Half Dome picture from some where around Turlock

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Ed Hartouni

Trad climber
Livermore, CA
Jan 18, 2010 - 05:23pm PT
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 = 1.4
at 50 miles this is 2.8

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 = 5.7

The moon will be at 6.56 at 1515 which means the shot has a 15 minute window around moon rise. The azimuth of the moon at that point will be 64.41

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!



wonder what the weather is going to be like?
wildone

climber
GHOST TOWN
Jan 18, 2010 - 06:16pm PT
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/
Clint Cummins

Trad climber
SF Bay area, CA
Jan 18, 2010 - 06:36pm PT
Awesome, Ed!
This would be a cool photo to seal the deal!
Ed Hartouni

Trad climber
Livermore, CA
Jan 18, 2010 - 07:26pm PT
wild1, I use KEH a lot...

Clint, all it takes is good weather... we can propose, the clouds dispose...
Reilly

Mountain climber
Monrovia, CA
Jan 18, 2010 - 07:43pm PT


Credit: Reilly

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.

Credit: Reilly
Clint Cummins

Trad climber
SF Bay area, CA
Jan 18, 2010 - 07:50pm PT
Reilly,

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.
Ed Hartouni

Trad climber
Livermore, CA
Jan 18, 2010 - 07:52pm PT
the bearing from Glacier point to the top of Half Dome is 61
the bearing from the Denair position to the top of Half Dome is 78

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 51 the effect of viewing the face at 10 from Glacier Point, and 27 at Denair, is quite different.
Clint Cummins

Trad climber
SF Bay area, CA
Jan 18, 2010 - 08:00pm PT
Ed,

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
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.
Ed Hartouni

Trad climber
Livermore, CA
Jan 18, 2010 - 08:20pm PT
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 6.5 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 300azimuth

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
Clint Cummins

Trad climber
SF Bay area, CA
Jan 18, 2010 - 08:31pm PT
Ed,

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!
corniss chopper

Mountain climber
san jose, ca
Jan 18, 2010 - 08:52pm PT
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 3732'46.26"N
longitude 12042'33.86"W
of the grain silo





GDavis

Social climber
SOL CAL
Jan 18, 2010 - 08:55pm PT
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.
Dick Erb

climber
June Lake, CA
Jan 18, 2010 - 09:04pm PT
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.
Clint Cummins

Trad climber
SF Bay area, CA
Jan 18, 2010 - 09:04pm PT
I'm giving Reilly points for explaining what seemed strange about the photo to him. That's half the battle sometimes.
Same for T H - he expressed his point well.
Ed Hartouni

Trad climber
Livermore, CA
Nov 26, 2012 - 01:39am PT
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.
Karl Baba

Trad climber
Yosemite, Ca
Nov 26, 2012 - 04:39am PT
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

Peace

Karl
The Alpine

climber
Nov 26, 2012 - 09:32am PT
100% most definitely a REAL image. Nice work on the math Ed. That would be a MEGA shot for someone to nail. Maybe team up with Jerry Dodrill?
Ed Hartouni

Trad climber
Livermore, CA
Nov 26, 2012 - 12:16pm PT
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)

Reilly

Mountain climber
The Other Monrovia- CA
Nov 26, 2012 - 12:24pm PT
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. ;-)
climbski2

Mountain climber
Anchorage AK, Reno NV
Nov 26, 2012 - 12:36pm PT
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.

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