Half Dome picture from some where around Turlock


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Ed Hartouni

Trad climber
Livermore, CA
Feb 24, 2013 - 11:36am PT
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...

...but it's still fun.
The Alpine

Feb 24, 2013 - 02:15pm PT
Nice efforts Ed!

Here's a little inspiration:

Kennewick wa
Feb 24, 2013 - 03:35pm PT
Am I the only one who doesn't understand half of what Ed writes? :)
Ed Hartouni

Trad climber
Livermore, CA
Feb 25, 2013 - 03:38am PT
well, close, and artistic, but not quite a success…

The schedule for today:

-2.38 78.87 17:00
0.00 80.77 17:13 moon rise
0.43 81.11 17:15
1.00 81.56 17:18 moon at Sierra Crest
3.26 83.34 17:30
6.11 85.56 17:45 sunset

80.77º true
67.05º magnetic

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
The Lisa

Trad climber
Da Bronx, NY
Feb 25, 2013 - 09:33am PT
Ed, this sleuthing work is fascinating. Sounds like you had a very productive day yesterday.
Ed Hartouni

Trad climber
Livermore, CA
Feb 27, 2013 - 03:23am PT
the crest...

now I'll be able to check the Moon position as a function of time with azimuth and altitude information... but not tonight.
john hansen

Topic Author's Reply - Feb 27, 2013 - 05:44am PT
That is pretty impresive Ed.

Trad climber
CA Central Coast
Feb 27, 2013 - 09:34am PT
Ed your efforts to get the shot are awesome.

thank you for sharing the journey.

Timid TopRope

Social climber
'used to be Paradise, CA
Feb 27, 2013 - 10:17am PT
Awesome image, effort and peak ID. Thanks for sharing your results.
mouse from merced

Trad climber
The finger of fate, my friends, is fickle.
Feb 27, 2013 - 10:47am PT
In your light we see light. Psalm 36: 9.

I must thank you, Eddly, for the explanation^^^. Lucid. Didactic, even! do you tap dance, too? :)

Oh, beauteous photos, too. Man-Oh-Man!
Mike Bolte

Trad climber
Planet Earth
Feb 27, 2013 - 11:20am PT
this. is. awesome.
Kurt Ettinger

Trad climber
Martinez, CA
Feb 27, 2013 - 01:20pm PT

Trad climber
the crowd MUST BE MOCKED...Mocked I tell you.
Feb 27, 2013 - 01:22pm PT
highly enjoyable

Like the peaks named image!

Trad climber
East Coast US
Feb 27, 2013 - 04:28pm PT
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.
Ed Hartouni

Trad climber
Livermore, CA
Feb 28, 2013 - 04:08pm PT
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.

john hansen

Topic Author's Reply - Dec 9, 2013 - 05:19pm PT
Since it has been so cold over there thought I would bump this and see what the viewing conditions are like.

Trad climber
South Pasadena, CA
Dec 9, 2013 - 05:37pm PT
Very nice stuff to see again... Ed, your curiosity and drive to action are inspiring.
Ed Hartouni

Trad climber
Livermore, CA
Dec 9, 2013 - 05:48pm PT
should be pretty good, though there is still ground moisture (warm soil, but probably getting cooler).

I posted this on another thread, from last week...

lots of "stuff" in the atmosphere at sunset... but this weekend is a full moon opportunity, I'll do a calculation and see what might be happening...

but certainly just shooting Half Dome should be a real possibility on these clear days...
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