Topic Author's Original Post - Jan 16, 2010 - 09:46pm PT
Trying to find that thread..
there were some directions to where it was taken from..
The next two weeks with all these storms backed up, there might be a break where you could catch it between the fronts ..with good light , in the afternoon. You know, if you just happen to be passing by.
Then again it might rain for the next two weeks straight.
Hall Road, .65 mile south of E. Keyes Rd. About 3.5 miles east of Denair, CA. and about 67.25 miles from Half Dome and in this image, shot at 400mm, the grain elevator is about 1.5 miles away.
I still say the perspective isn't right. Half Dome is too
tilted towards the viewer as it would look from above the valley
rim in a plane and not as it would look from the San Joaquin Valley
floor. There also doesn't appear to be adequate 'space' between the
grain silo and Half Dome. Nice job of 'shopping' IMHO.
Because the angle of the view is so low, atmospheric refraction is probably significant. The top of Half Dome is about 8700 feet higher than the central valley and if the photographer is 67 miles away, the geometric elevation is 1.4 degrees. This is small enough that the seeing-over-the-horizon effect may contribute.
Sometimes, you can lead a horse to water, but you can't make him drink!
:-)
I am certain such a photo is possible, because I have seen the lights in the central valley from the top of El Cap.
In Immoos' photo, it's clear a lot of El Cap is obscured by the intervening ridges, but we know Half Dome is above the Valley rim,
so we should be able to see pretty much all of the NW face, and this appears to be the case.
Because the distance of the shot is 67.25 miles from Half Dome,
the viewing angle is close to zero (or check arctan[(8800/5280)/67.25]) -
the angle is .025 radians = 1.42 degrees.
so the perspective is about the same as being level with the Valley rim,
or being on top of one of those intervening ridges.
" received another message concerning my Half Dome from Denair pic
informing me that it was not possible to see Half Dome from the central valley, therefore it was photoshopped...
What-everrrr. But it did get me looking at the image comments again and I clicked on brendon.m's link to www heywhatsthat com
Now I've done that before, but I had never before clicked the visibility cloak button.
The results are above and quite surprising. The top of Half Dome is theoretically visible from an incredibly large area.
Granted, from many places only the very top will be in view and difficult to see but I still find it fascinating.
If you live in the Central Valley anywhere in the red zone, get your binoculars,
telescopes or big telephoto camera lenses ready for the next clear day and catch a glimpse!"
And here's the map with the line of the shot -
areas in red are locations from which Half Dome is theoretically visible
(map not complete, because Mt. Diablo is not red).
(since I'm not the only one posting a huge photo):
The lack of "adequate space" between the silo and HD is due to to using a 400mm lense. A longer lens compresses the space between objects.
Think of all the images of the foothills or Smokey Mountains where the mountains look stacked up on one another. If you were standing there it doesn't look that way. Slap a long telephoto on and viola!
The image does look a bit "off".
There is another photo from the top of Mt Diablo (about 125 miles away) that you can see Half Dome in an enlargement. I tried to find it but couldn't.
There is a shot of HD taken from Mt Hamilton, Lick Observatory that I have seen. We had the reverse view from the big sloping ledge below the Robbin's traverse on HD. There was a dense layer of clouds across the central valley with really good lighting on Mt Hamilton, similar to looking through a tunnel. The cloud cover provided an effect like shading your eyes with your hand in bright sun light.
It is true - Half Dome is visible from the Central Valley on a clear day. I was extremely skeptical when I first read these threads a year ago. So we decided to check it out last March when the visibility was good. Sure enough, the unmistakable image of Half Dome was visible in the distance.
My photo isn't very good, but does show Half Dome.
Half Dome from the Central Valley
Credit: Rock Eagle
The coordinates where the photo was taken are N 37° 32.492 W 120° 44.229.
Of course agreeing with Clint. I just did the same research the last 30 minutes. Plus I too have seen Yosemite Valley a few times in the last 50 years, from the Central Valley. It is not that unusual; You only need 50-70 mile visibility, which often happens after fall-winter-spring storms. And Half Dome is 8836 ft high, so if you line it up through the mouth of the Valley, you have "Heywhatsthat.com's" visibility claim. Its simple math.
Further, I used the ruler tool and laid out the viewing vector from the spot the photo was taken from (It's actually marked on Google Earth) to the summit of Half Dome and aligning everything, El Cap included, to establish what we view in the photo. The two buildings are also there in the GE viewing.
So no the photo is not a composite but is a fun completely innocent and not-all-that unbelievable 400mm shot, actually.
One of my high school teachers, Phil Arnot, had a picture of HD taken from Mt. Hamilton...near San Jose. It was way cool.
A few years ago on a very clear winter day I took off from SJ on a commercial flight and you could see it clear as day once we circled around and gained a few thousand feet.
Surely that picture will crop up on the internet somewhere.
. . Not to weigh down the thread anymore , but look at the edges of the silo or whatever , they look so cut out / ragged compared to the telephone poles in the same area (the wires of the poles don't make sense either) . The photo on my original post is the original size , not an enlargement that would have anomalies or whatever . The camera is obviously of quality too . That's why I think the photo is cooked . Also there is a faint straight line going all the way across the middle of it that seems suspicious .
Er, the suspicious faint line I think you're referring to seems to have a slight droop and some possible birds (?) roosting on it at the right; are you sure it's not just an out of focus wire?
Again . . the wire is out of focus and the "birds" (more like fleas) are sharply in focus . You can't have the silo that in-focus along with Half Dome etc in the background unless the silo was at least about 10 miles away .
> look at the edges of the silo or whatever , they look so cut out / ragged compared to the telephone poles in the same area (the wires of the poles don't make sense either) . The photo on my original post is the original size , not an enlargement that would have anomalies or whatever . The camera is obviously of quality too . That's why I think the photo is cooked . Also there is a faint straight line going all the way across the middle of it that seems suspicious .
The cows, trees, grain elevators, roof to right, telephone/power poles, foothill ridges, El Cap, Half Dome, and peaks behind are all in focus.
The grass is the foreground is not. Looks normal to me for a good lens, shot with a small aperture (high F stop).
The telephone/power wires aren't ultra sharp, but that would be asking a lot from a lens at that distance.
Are you saying the grain elevators were pasted in?
They appear in the shots by other people, so they seem to be quite real.
Maybe what several people "feel" is wrong with the photo is that Half Dome looks "too big".
The harvest moon also looks "too big", because it's close to the horizon.
But I and many others believe the moon is real and is not changing size.
Maybe we get fooled by our feelings sometimes.
It may be wiser to be skeptical about your own feelings,
than to suspect others are trying to trick you.
"A wise fox checks his own hole first." :-)
or
"AT A CARDIAC ARREST, THE FIRST PROCEDURE IS TO TAKE YOUR OWN PULSE."
(rule 3. of The House of God) http://en.wikipedia.org/wiki/The_House_of_God
Its pretty simple to find... drive south on hwy 99 to Ceres. Go past Ceres and exit Hwy 99 at Keys Rd. On the overpass you can see it if you know where to look but you'll probably cause a traffic accident.
Drive east on Keys Rd... till it just starts to get hilly. If you go on Fed when the stone fruit blossoms are going off you will be treated to wonderful photog ops.
Its easy to see when there is snow on the mtns behind it.
Like I said go in late Feb when the stone fruits are in blossom. Its quite stunning, the green of the valley, the white and pink blossoms and the back drop of the mighty Sierra.
Just lovely.
Row upon row, farm after farm, a seductive carpet.
I always wanted to picnic with my honey on a big soft quilt out in one of these orchards. A bottle of chardonnay, some good cheese, a big fat skunk spliff hahahaha.
There are miles of these orchards, east of Turlock, south of Modesto. Seen from the air they are stunning as well.
OK, now to the goods.
HD, just above and slightly right of telephone pole.
Left part of image, above the closely spaced post fence line.
Between the garage and the house. This was taken at a public park in Denair.
Again, between house and garage. Now you can see even with a cheap digital pocket camera, the effect of telephoto. Its far more pronounced with a powerful lens.
After all this work a man needs sustenance. A killer carnitas taco from a convenience mart in Denair. Random stop, I noticed a lot of local hispanic farm workers milling about this store around lunch time and a hunch led me inward.... SCORE!!!!1111
I highly recommend the trip. Pack a picnic basket, grab your lover, take a big quilt and do some orchard love. You won't regret it... unless some Grapes of Wrath farm hand catches you that is.
For those of you who know Colorado....I was on top of La Plata Peak (in the Sawatch)with Craig Koontz when we had just completed the long arduous Ellingwood Ridge at about 2:00 in the afternoon. Craig had hauled a 1,000 mm lens with a doubler on it and a tri-pod up there . He was able to take a picture of Uncompaghre (in the San Juans, which I think is about 90 to 100 miles away as the crow flies, probably double that on the pavement) that filled the viewfinder. The hardest part of taking the picture was waiting to snap the photo between the rising "heat waves" that broke up the picture.
From Google Earth you can measure Half Dome and find that its face is:
0.53 miles wide
bearing 51º (or lays on the diagonal from the compass points SW to NE)
2000 m altitude at its base
2680 m altitude at its summit
-
680 m = 2231 ft = 0.42 miles tall
So roughly 0.5 miles by 0.5 miles.
At 100 miles distance this subtends the angle 0.5/100 = 0.005 radians
An object 1 mile away would subtend the same angle if it were 1 mile * 0.005 radians = .005 miles = 26 feet across.
Camera calculations for digital are confusing because they often quote lens sizes in "35mm equivalent" units... so I'll go with just 35 mm calculations.
For a 1000 mm lens the largest angle subtended by the film would be 35mm/1000mm = 0.035, Half Dome, at 100 miles would take up .005/.035 = 1/7 of the width of the landscape view of such a camera, or 14%
If viewed from the west, however, we have to divide the width of Half Dome by sqrt(2) = 1.414 (multiply by 0.707) and that would reduce the size to something like 10% of the picture width.
You can crop the picture to make the fraction of the frame Half Dome occupies larger... but at lower resolution.
With my FM2N I'd shoot a picture at a high f-stop but with a shutter speed not less than the lens size... my best lens for this would be the 180mm with a 2x teleconverter (TC-200) giving me 360 mm on film. This would make the angular width of the film of 0.10 radians, and half dome occupying 0.0025/0.100 = 2.5% of the film... digitized to 4000 dpi I'd see Half Dome in not more than 100 px wide.
Using the same lens on my digital camera, the equivalent focal length is 540 mm (with the teleconverter) which provides a somewhat larger image of Half Dome... 35mm/540mm = 0.065 radian at .0025/.065 = 3.8%, which gives an image of 163 px wide.
I have a 500 mm reflex lens, but I have found it problematic to shoot at a fixed f = 8, which does not produce images I desire... probably unload that lens and take a deep breath to buy a 400 mm prime telephoto (even used glass is pricey though).
Mr. Hartouni gets an A+ with a smiley face for his answer to the optics "word problem". All of the rest of us that took the test are pissed off cuz he wrecked the curve. :-)
the Moon's radius is 3474 kilometers, and it's distance from the Earth is 384403, so it subtends an angle of 2*3474/384403 = 0.018 radians 3x Half-Dome's 0.005 radian angle at 100 miles.
This means that you could pick a point to see the moonrise over Half Dome with the moon much larger than Half Dome... it would be killer!
So when might this happen?
The next full moon happens on Saturday 1/30/10, that day the moon rises around 1830, but unfortunately the sun set is at 1715 or so... you'd like to have some sun to illuminate your image.
On Wed 1/27/10 you could have a chance of shooting the moon in Yosemite Valley a la AA, moon rise is 1430 sunset is 1700, the moon's azimuth starts at 53.58º and at sunset is at 78.24º at an altitude of 25.38º sometime between those two times you'd get a great shot... but you would have to travel distance, pick a North-South road...
Your chance after this would be the week before Feb 28 2010...
The moon has to clear the Sierra crest, so say that's about 2.5 miles high, from 100 miles out that is an altitude angle of 2.5/100 = 0.025 radians = 1.4º
at 50 miles this is 2.8º
so the moon will be visible between 1445 and 1500 on 1/27/10
the maximum "height" of the film is for the 360 mm lens will be 0.1 radians = 5.7º
The moon will be at 6.56º at 1515 which means the shot has a 15 minute window around moon rise. The azimuth of the moon at that point will be 64.41º
According to the chart above, if you set yourself up on G St. in Merced between E Olive Ave and Yosemite Ave, you'd have a shot of the Moon Rise and Half Dome sometime between 1445 and 1515
Slightly better might be Thornton Rd, west of the airport between 140 and W. Dickenson Ferry Rd.
Or on S Gurr Rd (south of W. Dickenson Ferry Rd.)
Be prepared to move North-South, but you don't have a very big window to see Half Dome from this vantage point... maybe someone should be up on Snake Dike waving!
Ed, good work-thanks for your time.
Ever check out KEH.com for used high quality glass? Some pro photogs told me about it. I ordered a body and some lenses from them. They know how to assess used glass as they are nikon america's warranty workers.
They are also REALLY good for medium/large format stuff. http://www.keh.com/
So will someone please explain to me what has been my preeminent
argument all along? Why does this view of HD look like, as a pilot,
you are on approach to land on the summit? If you are at Glacier Pt
you sure don't see the top of the rock like you do in this view and
if you are 60 miles away at about 400' you sure as heck aren't going
to have this aspect.
I tried to explain about the viewing angle in an earlier post.
It's quite close to zero from Turlock/Denair.
From Glacier Point, you are looking up at a sharper angle, so the mountains on the other side of Half Dome don't appear above Half Dome as in Immoos' photo.
the bearing from Glacier point to the top of Half Dome is 61º
the bearing from the Denair position to the top of Half Dome is 78º
when you're at Denair your line-of-sight would put you North of Glacier Point...
the face of Half Dome, as I said above, lies along a bearing of 51º the effect of viewing the face at 10º from Glacier Point, and 27º at Denair, is quite different.
Another consideration for a "moon rise" Half Dome photo from the central valley is area from which Half Dome is visible (taking account of the intervening hills).
If we add your moonrise and moon "set" lines to part of the Half Dome visibility map from the first page of this thread, we get:
moonrise over Half Dome 2010.01.27
Credit: google, Ed, and Clint
The moonrise and moonset [not really set, but when the moon moves too high above Half Dome to have them next to each other in the photo] are visible below the diagonal black line.
According to the map, Half Dome is not visible (areas in red) from the center of Merced, and it is barely visible from part of highway 99 NW of Merced center.
More of Half Dome is visible further to the SW, so good locations might be: somewhere like Volta overpass at I-5 x 152 the "basalt recreation area" near the dam for San Luis Reservoir
All this assumes a really good lens and very favorable weather conditions.
not sure where you got your moon rise/set line Clint, I calculated it for the data (in an Excel spread sheet I made which should be good to arcseconds... the northern most line is the bearing of the moon at about 6.5º altitude, by which time it is too high to get in the picture with Half Dome with a telephoto lens...
The moon sets at 1/28/10 the next morning between 0530 and 0545 at slightly less than 300º azimuth
My azimuths, altitudes and times are calculated from that spread sheet for 1/27/10... if the weather is good I'll use my calcs and take a picture (which I was planning on doing, either in the Central Valley or in YV itself)...
The places I mentioned were in the triangular sliver that does go through "greater" Merced area near the 140W-99 intersection
Oops, what I meant by "set" was the upper line in your photo, when the moon moves out of position (too high above the shoulder of Half Dome to be similar to the Ansel Adams shot).
Sorry about my poor choice of terms there!
You'll notice that the left edge of Half Dome lines up with the top of the
Nose on El Cap. Used Google Earth to draw a line using those 2 point out into the central valley and found the grain silo in the picture in seconds
-assumed a line 67 miles long-
latitude 37°32'46.26"N
longitude 120°42'33.86"W
of the grain silo
Man, Reilly figured this one out. its so obviously fake. I can't believe all these working professionals in their respective fields have been duped by this image for so long.
Anyone who has bivied on the NW face of Half Dome in clear weather knows you can see lights in the Central Valley. As for the looks of the edges of the silo, there are a number of photo processing programs which cannot paste in objects like Photoshop, but can often produce unrealistic edges when the contrast or clarity of a photo is adjusted. I never suspected this as being a fake.
I'm giving Reilly points for explaining what seemed strange about the photo to him. That's half the battle sometimes.
Same for ß Î Ø T Ç H - he expressed his point well.
nursing a cold so didn't make it to the Valley,
but I decided to do some recon work on this photo... to get the Moon behind the Sierra Crest with Half Dome...
A problematic bearing... I set up along Santa Fe Ave. just north of Ballico...
the weather was horrible, lots of haze, Sierra wave going off, etc... so the seeing near the horizon was not great. I didn't see the Moon until it was quite high... and you can barely see the Sierra Crest.
Here's my first attempt at an analysis:
I've got to work on the pixel-to-angle conversion, the expected Moon diameter came out larger than it should be. I was about 2.5 miles North of where I wanted to be, but the orchards blocked the view.
I have to clean my camera sensor as it is pretty dirty (the black spots are on the sensor).
You can see that the expected position of Half Dome is at least plausible (it's something like 70 miles away). This photo was shot with my 180mm lens (so 270mm on the DX format) because I wanted to get a lot of the scene in for reconstruction. Not sure it is visible from this position though. Might be too close.
I'll also be working on identifying the peaks on the crest... which would give me a very good bearing mark.
Finally, I'll have to wait for a really cold day to get a clear view.
It's really astounding how revolutionary the internet is in getting information and critical analysis to people around the world in instants and how they can prove stuff to each other with other amazing research and tools available online.
This thread sort of reminds me of all the incredibile detail and science collaborations of people who have gone to online to prove the government story on 9-11 is a lie.
I'll leave it to you to decide if they made their case. In the case of this picture, I was surprised myself how a long lens can make an improbable looking image
probably only a couple or three chances a year... has to have excellent atmospheric conditions (we're talking about the central valley here, which is among the worst air quality in the country)
if Jerry (or anyone else) is interested, I'd be happy to have the company... but I think I could produce a nice image, too... yesterday wasn't a day that such an image could be made... but it provided a check on my calculations, and that opens the door for the future.
in terms of atmospheric conditions, it may also be affected by the fact that cold air flows down the canyon and clears out the valley air around the mouth of the canyon where it meets the valley. This is just a hypothesis right now, but most of the images that have been made that I've seen are in and around the same area. There is a sight line from Brushy Peak, just 10 miles away from me, and probably 90 to 100 miles distant, but I doubt the atmospheric conditions exist to actually shoot the image... (but I might try)
I could bring my 600mm (900mm DX equivalent) but, as you said, it's a cold
day in you-know-where when it isn't too hazy there. Ed's assessment of two
or three days a year might be on the optimistic side.
Ed, that sensor isn't dirty it's gross! Almost as bad as mine sometimes. ;-)
I would imagine that the reason the photo looks like it was photoshopped from an aircraft altitude would be because your effective elevation on the ground (near sea level) from 60 miles away is actually several thousand feet due to Half dome dropping down the curvature of the earth. Add a bit of diffraction and it would make sense.
Climbski, good diagram but the reason I was initially calling BS was because
it appeared to me that HD was actually tilted towards the Central Valley
rather than away from it on the perpendicular to the tangent at Point B.
Hey guys. I saw this on my own long ago, looong ago, one time from around the same area, but it wasn't on Santa Fe, it was even closer to the foothills. Monte Vista rings a bell...duh!
It seems to me that a reputable shootist like Immoos is going to put his best stuff up, which includes some of the rarest shots you could imagine. So why would he try to shop the photo? Makes no sense. What I'd like to see is a shot by Anders of Ed shooting the Dome! Ta-da! If Anders is unavailable, I volunteer!
Another shot worth trying, but lots harder, would be of the silo from the top of Half Dome. I am not volunteering for that one, fo sho!
Isn't that they way they caught Clinton? Some d00d hiked to the top of Mt. Whitney (might have been Longs Peak??) and he took a pic with a really powerful lens. He focused on the eastern horizon. I think it was an 800mm with a 2x teleconverter or something?
Anyway, he gets the pics back from the lab and ... low and behold, there was Bill Clinton ... passing a doobie to Mz Monica, on the Whitehouse's back porch!!
Of course, he claimed that he wasn't inhaling ... nor did he have sex, "With THAT women!"!
LOL!!
edit: Maybe you, (Jerry&Ed) cud check that one out also (from the Whitney/Longs, summits)!
edit: nuttin', just my twisted sense of humor, i suppose! ;)
i wonder what length of lens it would take to get that shot from Turlock? I think 'elcap pics' uses a 600mm! throw a 2x converter on that and I doubt it would still bring Half Dome that close. Maybe with a telescope lens hooked to a camera body like they use to shoot stars, planets and constellations, etc, eh?
EDIT: for instance; i have taken pics from the wawona tunnel with a 300mm lens and they did'nt come even near to looking as close/large as the OP pic!
SO, in regards to my comment in regards to Mt. Whitney/Longs Peak and Clinton, I was being facetious! becuz it looks photo-shopped to me!
I noticed the 400mm reference, but don't believe that would be nearly powerful enough! Like i have said, I have shots from the Wawona Tunnel with a 200mm and a 300mm lens and they are both tele's and fixed (focal length) at that mm (not zoom/were it could have been only partially zoomed in) and in neither shot does HD look that large!
edit: the shots i have were from an slr/nikon f3, from the mid/late 80's! I do have a digital camera today, but not sure how that would compare to my old film cameras vs the full frame sensors. the longest lens i currently use is a canon 70-200 f4 zoom!
plus, digital is much sharper than the old chrome slides (so i cud be wrong)!
67.25 miles from Half Dome and in this image, shot at 400mm, the grain elevator is about 1.5 miles away. I took many other images with my Sigma 135-400mm and Tamron 500mm mirror lens. On an Olympus DSLR that equates to a 270-800mm and 1000mm field of view compared to a 35mm SLR. This was the one that had the best focus of all the ones I looked at.
It looks like he's using an Olympus E-3, 3648 × 2736 .
here's a more careful analysis... I have included the effects of refraction though these may not entirely correct due to the local atmospheric conditions over the mountains...
it would have been nice to have had a clearer day to pick out the peaks on the crest...
like I said, I'd love to go out there with Jerry, and anyone else who's interested...
but it is a lot less interesting than watching climbers climb, believe me... for a Moon rise the whole scene is usually over in not more than a half hour, after hours and hours of preparation for the shoot... and you've got to have the weather cooperate all the way to the horizon...
this is not so bad when you're standing in Yosemite Valley, since you've had a whole day to shoot other interesting things (well, not the whole day, but usually the best parts just after sunrise and just before sunset... and maybe something in between). but when you're standing out in a fruit or nut grove somewhere in the vicinity of Turlock it definitely strains the imagination to find something interesting to do... the air museum at Castle Airport looks quite promising...
the next opportunity for a Moon Rise shot is 12/25-27/2012 (Tu, W, Th) with the last date having the Moon Rise just at Sunset which holds out the possibility of having alpinglow on the crest...
the bearings are around 65º which, for Half Dome, puts the shoot location very far south, roughly 5 miles north on Santa Fe Ave. from its intersection with 59 (ten miles south of the shot above)...
To shoot Half Dome from the central valley is somewhat less problematic... but challenging none-the-less
Here's what last Saturday looked like from Ahwanhee Meadows
there was about a 40 minute window to shoot, with the clouds ending it... close call... Sunday was worse (I thought it might be given the meteorological conditions over the crest I spied on my way to Escalon)... the sky was fine until about 3:30pm then the clouds came in obscuring the Moon.
Since I had gotten the shot from Ahwanhee Meadows a few times in the past, and still haven't completed my images, I thought to do something different this last weekend. Now it looks like that will be the new obsession.
I don't know if this website has been linked here. It is better than "hey what's that" at generating panoramas but it doesn't do the visibility cloak thing. http://www.peakfinder.org/
Ed-
I have a theodolite and tripod in the garage. It's old and not the most precise but it would work for identifying or locating peaks. Reads horizontal and vertical angles to the nearest minute and you can estimate to 6 seconds. The scope is 30x with a 1.5 degree field of view. I have California Topo! loaded on a laptop with a USB GPS so it is easy to calculate bearings from anyplace. One could relieve the boredom by setting up the theodolite, establishing a baseline and identifying peaks while waiting for the moonrise. Let me know if you think the theodolite would be useful or even just amusing.
I was on top of La Plata Peak in Co. with Gary and Craig Koontz. Craig had carried a 3000 mm lens up there (lot of extra weight for doing the Ellingwood Ridge). He took a picture of Uncompahgre Peak (in the San Juans) from the top of La Plata (in the Collegiates) that filled about a 1/3 of the lens (I'm guessing between 80 to 100 miles as the crow flies). Between the wind and the "heat waves" obscuring the image, he had to take about 30 pictures to get a good one.
Photo of the Sierra from Lick Observatory on Mt Hamilton (click for a larger version)
Credit: J. Fred Chappell
Some folks referred to this image. It is a mosaic of images taken on December 16, 1931 from Lick Observatory by Fred Chappell. This was a day after a storm had rolled through washing out the dust and haze looking across the central valley. The photographs were also taken on plates that were treated with "kryptocyanin" and filtered to only allow what they called infrared radiation then, but is probably around 900nm wavelength. This helped further to cut through the haze and to minimize atmospheric distortion.
The images were taken with a special camera with a 6-cm diameter lens with 1.5m focal length. This is one of the cameras that were built for photographing the area around the sun during a total solar eclipse to measure the deflection of starlight by the mass of the sun and test Einstein's theory of General Relativity.
There is a print up at Lick Observatory that is around 2.5m long and is really fun to stare at. There are at least three peaks misidentified in that big print. I think the IDs in the above jpg are correct.
Ed, Clint - smart and fun stuff you guys have put up on this thread!
EDIT: the canon lense up there is the 300mm f/4
EDIT 2: if anyone wants a larger version this photo, send me an e-mail via ST and I'll send you a 10k x 3k version
Reilly, I must admit I'm kind of a neophyte and might be getting focal length and focal distance mixed up. All I know is that lens he had was huge and added considerable weight to his pack, he called it a 3000, he mounted the lens on the tripod and then screwed the camera on to it.
I have a novice question about forshortening caused by telephoto lenses. Is the effect linear, or is it applied over a curve of some sort? Does f-stop alter the effect or just change the depth of field?
I am no expert, and out of respect to the photographer am not going to say anything about the reality of the image. What I am curious about and hope one of the experts can explain is why the forshortening in the picture appears to be greater in the distance between the siloh and the dome than between the dome and the distant peaks. Also the lighting of the dome and mountains looks so much different than the foreground lighting where the direction of the sun is very apparent. The background lighting looks ambient almost like a different time of day.
It is a very striking image, but I cannot get comfortable looking at it.
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Canon 5200mm F/14 Mirror Lens
Using a group of mirrors and a housing that's almost big enough to use as a coffin, Canon was able to stretch the focal-length on this SLR-specific lens to 5,150mm. Just how long does that make it? The original Canon info sheet claims its best used for photographing obects 18 to 32 miles away. In fact, in order for it tobe able to focus at all, your subject will have to be at least 120 meters (~394 feet) away.
Even with the mirrors to help keep things compact (at least compared to the previously mentioned 1,700mm Zeiss), the total package still weighs 220-pounds without the solid metal stand on which it's intended to sit. The rest of the measurements are just as impressive, including its 20-inch height, 24-inch width and its massive 75.6-inch length. There's currently a youtube video of it in action from a few months ago when one went up on ebay and sold for almost $50,000.
NEXT: Carl Zeiss' 50mm Planar f/0.70
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The 1700m f/4 lens on that site is also massive at 564 lbs.
How does he get an almost infinite and perfect depth of field and still shoot at 500 or 1000 mm or what ever he is shooting at?
That is like me getting a perfect shot of a hummers beak at 700 mm and having the entire forest around the bird also in focus.
When in reality my depth of field (in focus area) at that focal length is around 1 mm a best.
The pic doesn't make sense to me..
Im going with shopped as well.
Ironically the pic of Ousley on EL Cap isn't shopped as far as I know
The photog used a 400mm. He was 1,5 mile from the silo.
A 400mm at f/11 would have a near focus limit of 1353',
........................................ far focus limit of Infinity
and ................... a hyperfocus distance of 1856'
If he shot at f/8 the near focus would be 1331'
and the hyperfocus distance would be ...2625'
with the far focus still at INFINITY!
If it is real it is a much stranger and cooler pic than anything I have seen before.
No way you see half dome that close up at 400 mm from that distance?? can ya??
Im trying to imagine being far back from the silo and still getting it all in but it will still require huge focal length to magnify Half Dome that much.
My best guess is that it is two photos, the forground and the mountains, spliced together.
I dunno - i spent 2 years looking through a telescope at birds.
I just dont see how this works
peakfinder is cool, though I still don't have all of the peaks id'd, the one I had as Dana is Mt. Hoffman...
Lots of things are going on in the image that make it difficult to reconcile with "your gut"
interestingly, one of those things is that the Earth is a sphere, and it dips down out past your horizon... that skews a lot of perspectives and makes things difficult to place...
with a 500mm lens the entire view across a 35mm piece of film is 35/500 = 0.07 rad = 4.01º
at 4000 dpi on the film gives you 5512 pixels across that 35mm, Half Dome from the image position above is something like 0.16º or 220 pixels...
given that a standard STForum image is 800 pixels across, a crop with Half Dome centered on the image would have the middle quarter of the image filled up with Half Dome... and ±2º around that to view the Sierra Nevada, since the crest is only about 1.5º high you get everything in that scene, to the crest, and all the peaks on a 10 mile section subtended by the image plane.
I count 13 peaks in that area, 5 of them at about 12,000' elevation.
Getting the Moon in that picture, at 0.5º across would be like 670 pixels, basically the entire crop for STForum image...
This is a cool thread, I have no doubt the photos are real. I drove around looking for the silo a few times but the central vally is not real good for photo;s, unless they are after a storm.
I decided to analyze the photo referred to in the original post to see if it had been photoshopped.
The EXIF data from the original image records that the camera was an Olympus E-3 and that the focal length was 400mm (the photographer also states it was a 400mm lens). The EXIF also says that the image was processed using Silkypix software which is RAW image processing software. Being captured in RAW rather than JPEG format and processed in the RAW state may explain why it doesn’t look like the typical JPEG. All digital cameras have built in software that converts the image from RAW to JPEG format. The software built into cameras usually isn’t all that great. The image also has an embedded color profile.
Olympus E-3 has:
18.00 × 13.50 mm (0.7087 x 0.5315 inch) sensor
3648 × 2736 pixels (10.1 megapixels)
Aspect 4:3
The width of the field of view is 2arctan(9mm/400mm) or 2.57 degrees. The height of the field of view is 1.93 degrees. If the image hasn’t been cropped and ignoring small angle errors, in the original 1600x1200 pixel image, 1 degree is about 620 pixels. I believe the error in estimating angles this way is about 0.1% and much smaller than my other errors. I drew lines on the image at 1/10th degree intervals from which I find the left eave of the grain elevator is about 0.94 degrees left of image center and the peak of the shed roof is about 0.62 degrees right of image center.
Image with 1/10th degree grid. Grid scale may be off by 12 or 13%
Credit: Banquo
TOPO! Tells me that the top of Half Dome is 65.95 miles from the elevator on a bearing of 77.59 degrees (clockwise from north). In the reverse direction, the bearing from Half Dome to the elevator is 77.59+180=257.59 degrees.
Bearing and distance from Montpelier to Half Dome
Credit: Banquo
I copied some images from Google satellite and made a composite so I could lay things out. I drew a line from the left eave of the elevator roof on a bearing of 77.59-0.94 degrees and one from the peak of the shed roof at a bearing of 77.59+0.62 degrees. I extended these lines until they intersected. From the intersection I added a third line at a bearing of 77.59 degrees to represent image center and the summit of Half Dome.
Red lines are the bearings to the elevator, the shed roof and Half Dome. The lines converge in the canal.
Credit: Banquo
The lines intersect on the canal which is short of Hall Road where the photographer says he took the photo. If I extend the line it intersects Hall Road 0.65 miles south of E. Keyes Road. The photographer says he took the photo on Hall Road 0.65 miles south of E. Keyes Road. The fact that my projection came up a little short of Hall Road tells me that he cropped the image a bit, probably to put Half Dome in the image center or otherwise make it look better. Most likely it was cropped to level the image if the camera wasn't level.
Credit: Banquo
The intersection of my lines is 1.36 miles from the elevator while Hall Road is 1.57 miles which suggests he cropped the photo about 13.3%. The camera sensor is 3648 pixels wide so if he reduced by half he should get 1824 pixel width. The image is 1600 wide which is a reduction of 12.3% from 1824 pixels.
So, it seems clear to me that the image was taken from the exact spot he says it was taken from with the camera and lens he reports. I believe it has been cropped 12 or 13%. The image has also been processed for sharpness which has left some odd defects when inspected at full resolution. It doesn’t look like what the eye or a telescope sees because cameras don’t see the same way the human eye does and it has been enhanced a bit.
Also, the 2000 foot high NW face of Half Dome should be about arctan(2000/65.95*5280)=0.33 degrees high in the image which it appears to be although you can’t see the bottom of the face. Also, the grid scale is probably off due to the cropping.
Edit addition:
The dirt berm in the foreground is probably the canal. The dirt ramp to the right can be seen in the satellite image.
I think one of the most interesting things about this side view is getting a more accurate perspective of the relative heights of features within Yosemite (e.g. El Cap, Halfdome, and the mountains behind). When you're up in it, you just can't see that as clearly.
good work!
another interesting thing is that all of those locally vertical faces we seen in the Valley are leaning back about 1º (or more) from the vantage point of the Central Valley, which can distort the scene.
I don't doubt that shot at all, and am planning on getting it myself at some point in the not to distant future!
The Lick shot's so good, it's about the type of clarity needed to produce valley shot, but even moreso for the definitive shot, I bet.
Night before last I mentioned in a thread that yesterday was looking like it was gonna be such a day. It was cloudy up top above the Sierra day before yesterday, the wind was strong and cold out of the west, and the clouds were headed east quickly. Yesterday morning was a disappointment, really, though the view of the mtns was great, it wasn't crystal from cown here.
The view of the mountains has been excellent here the last couple of days. I can see crack systems on Patterson Bluff on the way home, with Mt. Goddard's new coat of snow in the background. Now if I only had remembered my camera (or even my phone).
So this thing is 100 percent?
There is no chance two pics were taken from the same exact place with the same camera and they were carefully photo shopped together?
Wed Dec 26 is still looking cloudy and possibly wet...
though the weather is certainly unsettled
Thur Dec 27 might have a weather window: clearing skies through the day and clear by 6pm (sunset at 4:50pm, which is when the moon rises... that would be spectacular timing with a snowy alpinglow on the Sierra crest..
here is the Moon rise ephemeris
the apparent altitude is calculated taking into account atmospheric refraction using Saemundson's expression:
R = 1.02/tan((pi/180)*(h+10.3/(h+5.11))/60 (in degrees)
and h is the true altitude (in degrees) the apparent altitude is:
h0 = h + R
[see Meeus p106 eq(16.4)]
that location is "good enough" for altitude... and time.
The Sierra Crest is at an altitude of about 1.2º to 1.5º (estimated from my previous attempt)
The bearings are shown on the map:
the red lines point to Half Dome, the central one at 65º and the upper and lower ones being 0.25º on either side, the angular diameter of the moon is 0.5º
the jagged white line is the Half Dome sight boundary, it is visible to the west of that line...
Given the existence of orchards of some sort along the Central Yosemite Hwy. (Hwy 140) it looks like good viewing would be in the field south of the Hwy, and west of Lincoln Rd, though no public roads access the west side of that apparently open field... another option is to go north on Sultana Dr. just a bit south of the aquaduct where there seem to be open fields...
The weather is still wavering for these days... Th is still "partially cloudy" and is worse than the previous Weather Underground report... The NWS calls it "partially sunny" with a chance of rain.
Great picture from Mt. Hamilton, Mike. If you get another chance/clear day, and have a red filter (perhaps left over from B+W photography), try also taking long distance photos with the red filter and converting to black and white. Less effect of haze due to scattering and absorption.
I have used a very red filter with a DSLR - you need a tripod because the DSLR is not very sensitive in the red due to an internal IR-blocking filter - to take photos that are almost near-IR. The reduction in haze means the landscape can have an appearance of immense depth. It is an effect that shouldn't be overused, but great for these long distance pictures.
Yup - I was up at Mt Hamilton for other business and was luck to have a long lens with me. If I have known what the view was going to be like I would have come better prepared with filters to push the response red and would have tried a few other tricks to increase contrast just in case.
Open up your camera and take out the IR filter. I've done this and it is pretty easy with some cameras - practically impossible with others. There are commercial services that do this too. Just google "ir camera conversion."
A red filter on an IR camera would make some cool images.
I converted an old, cheap, point and shoot, digital camera to infrared.
Credit: Banquo
Ed-
Finding an unobstructed view could be an issue. Have you thought about moving across the valley to the hills above I-5? I think Butts Road out of Gustine might work.
I think a lot of the critics of the size of Half Dome in this shot ignore that basic fact that the intervening atmosphere acts as a powerful lens enlarging images seen at the horizon. Hence, when you photograph a moon rise, say from Skyline Boulevard, looking east toward Mt Hamilton, the lunar disk, when it first emerges over the horizon, is much larger for a few moments before it ascends higher in the night sky. Sometimes the lunar disk on the horizon even appears at first in discontinuous wider and narrower bands. It seems like this phenomenon is stronger when the intervening atmosphere is more polluted too. Is this due to defraction of the light rays caused by the higher particle count in the atmosphere? Don't know about that, but am sure this shot is the real deal.
Bruce, Half Dome looks large because the photographer used a very long telephoto lens and was far away from the barn. Another way of thinking about it is that standing back from the barn made the barn look "small," but standing back a half mile or whatever doesn't change the apparent size of Half Dome much, since it is already many miles away.
Atmospheric refraction is real, but it just bends light, which causes some over-the-horizon and vertical squishing effects (looks like horizontal stretching, a little). It does not magnify objects. The reason that the moon appears larger when near the horizon is an optical illusion, whose origin is not that well understood: http://en.wikipedia.org/wiki/Moon_illusion
John I don't know if anyone has posted did read all of them...You can catch Keyes road off highway 99 just past Ceres and just before Turlock. It is posted. You will have to travel east for a while as you make your way out of the urban areas. Years ago I used to be able to catch a glimpse of what I though was Half dome out of my back door right after a good storm. I am about 60 miles away as the crow flies.
the combined effects of atmospheric refraction and the curvature of the Earth highlight the fact
that what we perceive may lead us to conclusions that are very different then what the
"actual" scene presents.
the angular diameters of the Moon and the Sun are roughly 0.5º, which is close to the angular
diameter of your thumb held at arms length. The appearance of a "huge moon" on the horizon
can be blotted out by your thumb... (as with the sun at sunset) demonstrating that the actual
angular diameter is not changed significantly.
Atmospheric refraction will change the position of the moon with respect to the horizon, and the
horizon that you view is not the position of the local level of the ground. For instance, if you had
a laser level at the position I was at in the central valley for the shot above, it's "dot" would be
roughly 2000' above sea level in Yosemite (though still below the local surface level). However,
our perception of the Valley, part of which is the perspective we keep in our minds from
familiarity of he place, would seem to suggest that the images produced from the valley were very
different from what we would expect.
In general we do not experience the spherical Earth phenomena, and our perception does not
incorporate it in a scene which it plays an important role... so while most people on this thread
"accept" the theoretical notion that the Earth is a sphere, they would argue passionately that the
view of Half Dome doesn't correspond to their perception of that scene, and therefore the image
is false.
Shades of the inquisition of Galileo...
In some odd way, our perceptual adaptations still dominate our thinking, even though we have
knowledge contrary to those perceptions.
wed looks dreary, sorta like today...
thu looks less definite, with some cloud cover forecast... but the weather model shows hopeful signs as well as the forecasts
thought that the atmosphere would be the problem tonight, it was the low clouds hanging on the Sierra, and obscuring the Sun set...
...got to see the Moon rise over the crest, though, but no Half Dome view...
I'm still analyzing the images to get an idea of my calculations for the next time, here are the 71 images I shot at 30 second increments. It's still a great thing to see the Moon rise on the horizon when and where you expect it too... set the camera up, and let it shot automatically.
shot with my Fujifilm S5-Pro and Nikon 180mm lens
ISO 100, 1/125 s exposures
varying apertures f11, 8, 5.6, and 4 corrected with Photoshop
timed with Nikon MC-36 15s increments alternating between "mirror up" and "expose"
Back in 1975, sitting in Don Reid's van in C4, he showed me a photo of Half Dome (and a bit of the Valley), taken from the top of Mt Diablo. Now the crap sandstone on Mt Diablo is where I cut my teeth climbing, and I was up there a lot from 1970-74.
I wasn't sure if the photo was real. Several years later, back up on my old stomping grounds and I went to the summit with a friend's telescope. Sure enough, there it was. It was a very clear day with no haze, fog or smog. And the top of El Cap was also visible.
They say you can also see Mt Shasta from the top of Diablo. I never have.
I went to take a look but from a different spot than Ed. I opted for a shorter drive from my house. This was taken from the I5 overpass at Taglio Road near Gustine.
From my location Half Dome should have been in a bearing of 66.3 degrees and 92.5 miles away. I've sketched in Half Dome roughly the correct size but I simply guessed how high to place it in the image. The clock in my camera was about 12 seconds slow if you check the EXIF data.
From my personal experience its the snowy backdrop of the high Sierra behind, which renders Half Dome visible. Given the sun will have set and the moon is rising behind half dome, doesn't this lighting play against the goal?
Yeah, moon photography is a problem. The moon is in full sunlight and should be exposed accordingly. Dusk is getting pretty dark for the terrestrial part of the image. Summer would be good since the sun sets much later but the visibility is never good then.
The next full moon is on Jan 27 but it doesn't rise until 6:30 pm when it will be too dark to see half dome.
On January 24 the moon will be 95% and rises at 3:30. This might be good enough if it is clear.
the trick will be to get the Moon rise with sun still on Half Dome
and with a very long lens... which stresses the accuracy of the calculation of the trajectory of the Moon as seen from some location in the central valley...
I'd hope to get 360mm or 500mm lens on the scene, perhaps even 1000mm if the light is excellent...
the angular field-of-view at 1000mm is about 1.4º on my sensor, the Moon is 0.5º so it takes up a very large area, but it's also moving fast, requiring a quick exposure time... the aperture can be set larger than the typical full Moon setting of f11 at 1/125 s because the atmospheric attenuation is large viewing it on the horizon... looks like f4 at 1/125 s was fine for my last effort... 3 stops down (1/8 th the light) but that doesn't give much room for the exposure unless the lens is very fast (my 500 mm reflex is f8, with a x2 teleconverter this goes to f11)... if the scene is too light, the Moon-sky contrast is not so great and the effect is diminished...
Good, long focal length lenses are terrifically expensive. I see some nice ones in the 10 k$ range but I won't be buying one. I have a super cheap 500mm reflex lens but it is hard to get good photos with. My aging eyes have trouble with the manual focus and like all reflex lenses the contrast is poor. If one had a big mega pixel camera and a good lens in the 200mm range, a cropped image might do.
I did learn a few things yesterday that will be helpful if I try again. The position predicted by the Naval Observatory seems to match the photo I got. It seems like they must account for atmospheric effects. I would try to get an image when they predict the moon is about 0.7 degrees elevation. I think it would look best with the moon a bit left of HD so I should have been a bit farther south than I was.
My next target is about 3:27 pm on January 24. The moon will be on a bearing of 64.5 degrees. I think a position along a bearing of 65 degrees from HD would be just about right. By I5 where Butts Road crosses the California Aqueduct would work and There is some elevation there to look over the orchards. Also Lincoln Blvd about 0.5 mile south of 140 if there is a clear view from there.
right now my climbing schedule will have me in Cody WY on the 24th... so I'll miss that one... try for Feb.
I suspect that the differences between the "apparent" altitude and the "actual" would be more to do with timing than with position as the corrections are pretty small...
most of the lenses I've bought are used, that brings the price down a bit... and getting a teleconverter 1.4x and 2x helps though they can soften the focus a bit and reduce the light by a half stop to a full stop, with fast primes I haven't found this to be a limitation.
Isn't 1/125th a little slow for a 500 without VR? I suppose with the
mirror up on a good tripod it will do? How fast does the moon move?
I know you mentioned it before but I guess 1/125 is fast enough for that?
the first hint of the Moon was at 16:48
here rising over the Sierra crest
This was a bit later than I had expected in my calculations, but points out a problem with this shoot, I didn't setup good landmarks for determining azimuth or altitude... owing to the fact that I had gone with the expectation of seeing Half Dome which would have been the landmark.
In the future I'll have to make sure to have secondary "targets" to establish the directions from my station.
The data from the images with the moon are seen in this plot of apparent altitude versus azimuth:
which shows the expected trajectory as the red dashed line. This is consistent with a 0.29º shift in azimuth which is very possible since I established the azimuth off of the pine tree in the image above... about 3/4 miles away.
Another task for this shoot was to establish probable exposures. The image above was shot at f8, 1/125s and ISO 100, and was very dark (the image is corrected in Photoshop with Brightness=2.94 to make it equivalent to f4) . I could have shot at f4, two stops down. The bright Moon overhead is usually shot at f11. You expect that the light going through the atmosphere is attenuated more at the horizon since the length through the atmosphere is longer than when the Moon is at its zenith (over head). I averaged the brightness of the pixels on the moon images as a function of apparent altitude and was surprised to see this:
the red dots are the data, the 6 "low" points are taken with f8 (the lowest) f5.6 (the two intermediate) the rest at f4... a rough correction shows that the Moon gets brighter as it ascends, but that there is a point below which it doesn't change. The solid line is what you'd expect if the attenuation was due to the light's travel length in the atmosphere.
Thinking about this it is possible to contrive an explanation which has all of the light of a particular wavelength extinguished, while light of other wavelengths is passed, which could be due to aerosol size, for instance, so it is not unreasonable. Once the path length gets short enough, the light starts to get through and the overall brightness of the Moon increases.
The speed of the Moon here is 0.0037º/s, and for this camera with this lens that translates into a 2.1 pixel/s motion. Blur due to the Moon's transit will not be a factor at 1/125 s exposure times, basically 0.02 px... The distortions of the image are due to the convection changing the index of refraction along the light path.
The whole scene would have been nice in this image:
with Half Dome down and to the left of the Moon... but for the clouds...
The darkness of the foothills is due to low cloud cover all the way out to the coast... the hope would have been for clear skies and an alpinglow cast on the Sierra, and Half Dome.
The reason for all the calculations is that the shot doesn't last that long, so everything has to be setup for the shot ahead of time... and basically happening automatically during the time. Here is what the different lens Fields-of-View look like:
where the bright purple line is the presumed azimuth of Half Dome. Had the conditions been excellent I might have attempted the shot with my 500mm reflex and the x2 teleconverter, so 1000mm effective, but at f16 fixed I'd have had to decrease my exposure times to 1/8 s, the Moon would be traveling across the scene at 12 px/s, which would have lead to a 1.5 pixel blur, probably not horrible given the very soft focus of that lens combination.
With these calculations I would have gotten the shot having lined up on Half Dome. That's good to know, I would probably not have gotten a good exposure, but I'll work on setting up automatic bracketing in the camera.
I'd love to get that shot though... for me February will be the next possible time... maybe Banquo will have something for us in late January!
The weather forecast is for cloudy on Fri and Sat, and clear on Sun, then it get's cloudy again, so there is a small window which is a moving target...
On Sunday, the closest location in the Half Dome view space is on Montpellier Rd., 0.2 miles south of the intersection with Hall Rd. looks like open fields to the east in Google Earth.
ok, missed yesterday... couldn't work it into the schedule....
four potential sites for today, listed in order of distance:
site 1: on East Ave., 0.95 miles east of Santa Fe Ave
site 2: on Santa Fe Ave, 0.28 miles southeast of the intersection with East Ave.
site 3: on N. Vincent Rd., 0.48 miles south of East Ave.
site 4: on S. Story Rd, 0.69 miles south of East Ave.
main criteria will be visual sighting of Half Dome... hopefully it will be breezy enough to blow the haze away...
These are on the azimuthal bearing of the moon rise, the moon will be slightly south of Half Dome when it appears over the Sierra crest at roughly 16:15
I'll bring a lot of cameras and get other "opportunity shots" if the blossom is in
I plan on being on site an hour before the moon rise... but I don't know which of these 4 places I'll be...
The valley air looks pretty clear, and the Moon looks great,, you can see the clouds over the coast range and the mountains accross the vally, nice photo. someday soon, perhaps tomorrow.
I keep looking for some signs like the wind last night, and the chill as a result, hoping for clarity. This a.m. the mountains just seemed so far away compared to other days. It's really clear, but the distance seems rather MORE distant than close, in comparison with other clear mornings...
I'll start differently today... on the west side of the Central Valley southeast of Grayson (on Elm Ave near Loquat Ave) and move along the moon-rise-over-half-dome bearing of 80.77º with the intention of spotting Half Dome first...
8 potential sites are identified on the basis of the Google Earth (GE) indicator of possible locations with a view (e.g. no groves or buildings)... the altitude of the Sierra Crest is about 1º (0.0175 radians) which means that a 20' tall tree obscures the view if you're closer than 1146' (0.21 miles)...
This is more of a problem farther away from Half Dome than closer... but it provides a bigger range of possibilities of views.
another improvement for today: I finally looked up the magnetic declination in the area, -13.72º (magnetic north is east of true, e.g. GE, north) which means I can use my compass to get an idea of just where I'm looking rather than trying to do that off of sight cues, I don't know the Sierra Crest that well (yet) and even if I did, the cloud cover obscures many of the important points.
the farthest east potential view point is on Montpellier Rd south of Hickman (just south of the intersection of Hall Rd.)
as far as why it looks so far and seems to be clear?
don't know exactly but we perceive distance by a number of cues, one of which is the "atmosphere" which attenuates light as a function of the distance it travels... the ground fog this morning gives you 100% humidity near the ground, so the base of the mountains might look far, but the tops of the mountains don't travel through as much atmosphere, the humidity might be half or less... so the tops look close... your brain puts that all together and the result is a rhetorical question...
the humidity today isn't going to be very low, 54% around the time of sunset, and 18% cloud cover... so I'm not hoping for too much...
for photography you want to have clouds, but in the right place... given the constraints of this shoot, it's a timing issue... and so far the timing hasn't happened...
after a morning gym sesh with Dr. Sharpe I launched from home with a thorough plan, 8 possible view points. The drive over and back from Sunnyvale was revealing high clouds, lots of moisture, and still winds aloft which seemed considerable.
I was on the road by 1:10pm and after a fuel up the first real indication of conditions was summiting Altamont Pass on I-580, and I saw the snow clad Sierra. That was a relief since actually seeing it gave me a chance.
Starting this quest from East to West the first stop was near Westley. But I blew the approach by not having my instructions and ended up way South. Still, I had plenty of time, I arrived at "Site 8" at 3:06pm, which was supposed to be 0.1 mile SE on Elm Ave from Loquat Ave… 37.52988ºN, 121.12800ºW which was about 123' short of my intended line… not bad.
Sighting Half Dome was the main task, and though it was hazy, and this location was 88.71 miles from the summit, I still was able to locate it and get two images, one with the 180mm x2 and one with the 500mm x2:
Half Dome is just up an left of the tower at image center.
It is HUGE compared to the background… didn't expect that, at least with a 1500mm lens (equivalent on the DX format sensor).
The next stop "Site 7" was on Vivian Ave 0.73 miles south of W. Keyes Rd. at 3:34pm, my location was 37.54195ºN, 121.04860ºW, which was 390' north of where I intended… once again, Half Dome was located and shot:
look just above the "barn" slight left of center in the image…
here with the longer lens. This site was 84.32 miles away.
Site 6 was at 37.54760ºN, 120.99370ºW, 385' south of the line, the view was obstructed by hedges on the road and at the other side of that particular lot of land. When I look at Google Earth (GE) again I can see the hedges, the shadow angle didn't reveal their height.
I missed Site 5, didn't write the distance down, Site 4 view was obstructed by trees, as was Site 3. These trees were distant on the GE look, but the tree height was sufficient to block the Sierra crest view. I hit the Site 3 location at 37.56570ºN, -120.87272ºW just 27 feet East of intended. My anxiety was rising, however, since I hadn't spotted Half Dome since Site 7, there was little more than an hour to Moon Rise and the thought of going all the way back to Site 8, the best view of the two seemed a bit improbable.
I landed at Site 2 at 4:15pm and found it to be a terrific site, though I was having trouble spotting Half Dome. With time running short a quick hope over to Site 1 revealed it to be obstructed by a hill and trees, so quickly back to Site 2 at 4:26pm, 37.58155ºN, 120.75567ºW, 212 feet South of the intended position.
With the view, and the low light, I didn't see Half Dome. I should have looked at the set of images that I had taken, but decided, instead on going with a slightly wider angular field of view afforded by the 180mm x2 combination 3.66º and hope to find Half Dome in the image.
This was the scene:
and you'll notice right away that Half Dome isn't there, it's off frame to the left. This should have been a disaster, but it wasn't, somehow I messed up my calculation of the azimuth of the Moon Rise, or the bearing from the view point.
My times where correct, however, though in disagreement with Debbie's Garmin GPS Celestial page information. Of course this caused a lot of angst (GPS calculated 3 minutes earlier). I expected the Moon to be at the Sierra Crest around 5:18pm.
Having setup, I started the exposure timer at 5:05pm. This was set to "click" every 7 seconds. I had the camera in "mirror up" mode, so the first "click" brought the mirror up, the "click" after that exposed an image. I also had the camera "auto bracket" the exposure +/- 0.7 stops. In this mode the timer "clicked" the mirror up, then "clicked" an exposure with my settings, then clicked the mirror up, exposed with +0.7 stops then clicked the mirror up, and exposed with -0.7 stops. So every 6x7=42 seconds the process repeated itself.
I had the iPod tunes running and the binoculars out trying to chill. The haze was a bother, but the state of the atmosphere east of the Sierra crest was an unknown. The Moon will arrive like the Cheshire Cat's smile, slowly emerging from the mirk, it's not obvious at first, but then it is there:
By my calculation, this should have been off the image to the left…
two minutes later:
I dropped out the x2 Teleconverter and got a wider view:
if you're good you can pick out the top of Half Dome just above the foreground ridge in the bottom left of the image… I'll ID the peaks over the next week, too tired to do it now.
final view through the haze…
My calculations were off, I'll ponder that too... and the images need a bit more work, this is a quick pass through
Cool stuff. I climbed the RNWF almost 21 years ago and I remember looking west as far as I could see from Big Sandy Ledge. It felt like I could see the ocean, which might have been Turlock.
the distance of the horizon that you can see from a particular altitude is given by a simple formula (in which things just work out... if you don't believe me, do the calculation yourself):
horizon distance in miles = square root of your altitude in feet
so at the top of Half Dome, at roughly 9000' the horizon is 94.5 miles, not correcting for atmospheric refraction, which will take you out a little bit further than my site 8 which was nearly 89 miles distant. The horizon you would see from Half Dome would be the hills that define the eastern boundary of the Central Valley.
somewhere like Volta
Let us know!