Half Dome picture from some where around Turlock

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Messages 81 - 100 of total 178 in this topic << First  |  < Previous  |  Show All  |  Next >  |  Last >>
Banquo

climber
Amerricka
Nov 27, 2012 - 11:14am PT
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.

Dan

Credit: Banquo
The Alpine

climber
Nov 27, 2012 - 11:41am PT
Johnboy - exactly which objects do you think are equidistant?

Foreshortening....
http://en.wikipedia.org/wiki/Perspective_distortion_%28photography%29
ydpl8s

Trad climber
Santa Monica, California
Nov 27, 2012 - 12:56pm PT
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.
Reilly

Mountain climber
The Other Monrovia- CA
Nov 27, 2012 - 01:05pm PT
Who makes a 3000mm lens?
ydpl8s

Trad climber
Santa Monica, California
Nov 27, 2012 - 01:12pm PT
Canon, for one.

Canon
Canon
Credit: ydpl8s
Jerry Dodrill

climber
Sebastopol
Nov 27, 2012 - 01:13pm PT
The thing is, aside from having a sacred rock in it, its not really that interesting of an image.
Reilly

Mountain climber
The Other Monrovia- CA
Nov 27, 2012 - 01:18pm PT
Isn't that a 300? :-)
Mike Bolte

Trad climber
Planet Earth
Nov 27, 2012 - 01:38pm PT
Photo of the Sierra from Lick Observatory on Mt Hamilton &#40;click fo...
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

ydpl8s

Trad climber
Santa Monica, California
Nov 27, 2012 - 01:52pm PT
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.
Ksolem

Trad climber
Monrovia, California
Nov 27, 2012 - 02:33pm PT
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.
Jerry Dodrill

climber
Sebastopol
Nov 27, 2012 - 03:12pm PT
Ed, My quick analysis concludes that the best bet for a moonrise is January 26 from somewhere near the Turlock Municipal Airport.
Chewybacca

Trad climber
Montana, Whitefish
Nov 27, 2012 - 04:40pm PT
I've never heard of a 3,000 mm lens but here is a 5,200 m f/14 Canon lens. At 220 lbs I doubt I would want to hump it up any peaks. http://www.popphoto.com/gallery/9-unbelievable-camera-lenses-actually-exist?image=4

9 Unbelievable Camera Lenses That Actually Exist
These rare lenses come with unbelievable specs and spectacular price tags.

By Theano Nikitas on July 8, 2010

< Prev
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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

;


The 1700m f/4 lens on that site is also massive at 564 lbs.
Reilly

Mountain climber
The Other Monrovia- CA
Nov 27, 2012 - 04:48pm PT
Chewy, is that a full-frame or DX lens? ;-)
Reilly

Mountain climber
The Other Monrovia- CA
Nov 27, 2012 - 05:12pm PT
You can read up on DOF and hyperfocal distance here:

Hyperfocal Distance

There are four pages to this tutorial and on the fourth page you can get a
link to an iPhone app!
Reilly

Mountain climber
The Other Monrovia- CA
Nov 27, 2012 - 05:47pm PT
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!


It's still bogus. ;-)
climbski2

Mountain climber
Anchorage AK, Reno NV
Nov 27, 2012 - 05:48pm PT
When the foreground is over a half mile away it's not that hard. The exact location is available on google and the photo is attached on google earth.
Banquo

climber
Amerricka
Nov 27, 2012 - 06:07pm PT
Here is the peakfinder view from the silo.

Credit: Banquo
Ed Hartouni

Trad climber
Livermore, CA
Nov 28, 2012 - 12:12am PT
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 = 4.01

at 4000 dpi on the film gives you 5512 pixels across that 35mm, Half Dome from the image position above is something like 0.16 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 2 around that to view the Sierra Nevada, since the crest is only about 1.5 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 0.5 across would be like 670 pixels, basically the entire crop for STForum image...
john hansen

climber
Topic Author's Reply - Nov 28, 2012 - 01:05am PT
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.



Jerry and Ed.,,..


The dream team, the moon and the sun...





Ed Hartouni

Trad climber
Livermore, CA
Nov 28, 2012 - 01:18am PT
from my calculations, on 12/26/2012 the bearing of the Moon when it is at the same apparent altitude as Half Dome will be 64.76 at essentially 4:00pm

Taking that bearing from Half Dome into the Central Valley gives the black line:


looks like there is a spot on McSwain Rd. which would allow some visibility...

Doesn't look great though for this Moonrise, it would be preferable to have something further North.

When the visibility here is greater than 70 miles then we've got it made!
http://forecast.weather.gov/MapClick.php?lat=37.367779&lon=-120.558334&site=all&smap=1&searchresult=Castle%20AIRPORT-MER%20%28MER%29%2C%20Atwater%2C%20CA%2095301%2C%20USA
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