Just to document how to calculate the exposure of Ansel Adam Moonrise

[dng88]

After 5 year missing the filter calculation, I finally get around how to do the calculation (even though it is not that unclear in the original description in the book Examples - the making of 40 photographs or here
http://www.anseladams.com/content/an...ancedotes.html

- ISO 64 for a moon at 250 c/ft2 mean f8@ 1/250s for zone V.
(exposure calculation Example p. 174-175;
which meant EV 14-2/3@ISO100 or EV14@ISO64)
- to zone VII the moon is now at f8@1/60s
- filter is Wratten No. 15 (G) filter with filter factor 3
(See http://www.kodak.com/US/plugins/acro...h2_filters.pdf Kodak said filter factor 3 means 1-2/3 additional stop is required.)

it will be f8@1/20 or f32@.8s approx. f32@1s used by Ansel

The only one remained not sure is how the lens is being used. I have a cloned triplet and I am not sure which element is being used (the back one?) and how it was placed (in the front?)

BTW, the Moon and Half Dome (p.133) use 400 c/ft2 by adding 150 c/ft2 sky on top of the moon 250 c/ft2 with filter factor 4 (or 2 stop).

[BrianShaw]

Wonderful trivia! I have one for you: did you know he had bacon and eggs, washed down with a cup of coffee, for breakfast that morning?

[Ron Marshall]

Didn't he use BTZS on his Palm Pilot?

[Eric Leppanen]

The only one remained not sure is how the lens is being used. I have a cloned triplet and I am not sure which element is being used (the back one?) and how it was placed (in the front?)

Here is an excerpt from The Negative, where Ansel describes how he took Moonrise (page 127):

I had to exchange the front and back elements of my Cooke lens, attaching the 23 inch element in the front, with a glass G filter (#15) behind the shutter...I knew that because of the focus shift of the single lens component, I had to advance the focus about 3/32 inch when I used f/32.

I always thought Ansel used a Cooke XV convertible for this shot, but if this is correct, it is unclear which focal length he used, at least based on the above description. For one thing, there is no 23-inch focal length to the Cooke XV (it supports focal lengths of 12.25, 19 and 25.5 inches). It's also unclear what exactly he meant by "exchanging the front and rear elements", as his description otherwise seems to imply that he used only a single "23 inch" element in taking the shot.

So it would seem either Ansel incorrectly recalled the focal length while writing The Negative many years later, or he used a different lens.

[Greg Lockrey]

Maybe he was just a good BS'r. Blasphemy!

[dng88]

I understood the issue when one talks about St. Ansel (as some said). Moonrise is one of his most famous picture (if not the most), some comic relief is expected. However, the issue is not that trivial.

First let us start with the way he deal with the situation in the split seconds (he was 4 seconds too late for the second photos). He took the picture by using the highlight! Expose for the highlight, ... really. But that is what he did. Hence the later problem of being a bit difficult to print. On the other hand, he did not have the choice.

The key to that is the exposure value of the moon. We have two major sources of available natural light (the sun and the moon). Unlike the sun (which is either very bright white or surprisingly turn into a dark spot if too over-exposed), the moon we have the issue of whether to keep the details (zone VII or zone VIII, St. Ansel speak). The problem when we have the moon, everywhere is dark (but not that dark in full moon). How to do the exposure is the problem. I still not able to solve this. But by solving this trivial question which bugs me for five years, I have at least confirmed the EV@ISO 100 of the moon purely by itself is 14-2/3 and with a clear sky a bit higher. One subject solved. If one exposure for shadow, one can check the development time where you put the moon is (it is normally way beyond zone VIII, e.g. EV7 meant zone 12 whilst in the case of Moonrise, the foreground is in zone II i.e. EV9-2/3). Need to get your BTZS tube out I guess for this one but cannot save St. Ansel -- he has to use intensifer instead of the tube :-).

Anyway, it solved one of the puzzle and instead of always taking digital picture with moon as the main source of light (plus street lamp), I guess I can now use my large format to do it.

For the lens issue, I would do a bit more research. Hopefully, not another 5 years (but I did have a habit of posting comment in Photo.net after the thread has not been discussed for 5 years. It is not unusual it seems, as I guess there is a major surge of guys who after taking digital going back to film and found that old thread is very useful to understand those auction site and day-to-day film camera things. I document it here in case someone has the same silly questions of missing the factor factor is a 2-power thing. 2 to the power of 1-2/3 is 3.)

Good nights for now and have a good breakfast in America / Europe.

[dng88]

On the lens part, a preliminary search it seemed there is some conflicting sayings (with explicit link to St. Ansel)

http://www.f32.net/Services/Equipment/Lenses/cooke.php mention "All three combinations cover 8x10 at infinity. The combinations are 12.25 inch, 312mm, f/6.8. Back: 19 inch, 483mm, f/12.5. Front: 26.50 inch, 673mm, f/16." but then http://www.hctc.commnet.edu/artmuseu...illiamson.html mentioned "Lens: Cooke Series XV lens (a 12 1/4 -inch triple convertible with components of 19- and 23-inch focal length)." One note that both mention 12.x and 19 but one said 23 and one said 26.x inches.

The 23 inches seems odd man out as Cooke in getting out the new Cooke Series XVa mentioned that "he Series XVa has the same classic lines and the same focal length combinations as the original Cooke Series XV lens that Adams used to capture fourteen of his most famous images, including "Moonrise." Cooke's redesign of the popular classic maintains the favourite characteristics of the original lens while incorporating new features requested by contemporary photographers:

Focal lengths: 311mm (front + rear), 646mm (front cell only), 476mm (rear cell only)" which is also 12.25, 19 and 25.5 (but note it is neither 26.x inches or 23.x inchese but 25.x inches...) One wonder.

That is enough for one night.

[Brian Ellis]

Didn't he use BTZS on his Palm Pilot?

No, he probably wouldn't have had time to punch in the numbers. But he would have gotten a better negative if he did have the time. Actually it would have presented him with an interesting dilemma - do I use my Palm Pilot and risk losing the shot or do I go with my quick mental calculations and risk an unprintable negative? Given the time situation, while contemplating the dilemma he probably would have lost the shot entirely.

As it was, a straight print from the negative he did get is vastly different from the print you actually see. I've always thought it was a real tribute to Adams that he recognized the possibilities in the negative. I likely would have made one proof from that negative forgotten about it.

[Deane Johnson]

I've always thought it was a real tribute to Adams that he recognized the possibilities in the negative.

That is, indeed, the greatest tribute to Adams rather than the exposure calculation. It actually goes back further than that. I saw the location many years ago before it had been so drastically altered, and to envision a great photograph looking at the raw seen took a very trained and visionary eye.

[Ron Marshall]

No, he probably wouldn't have had time to punch in the numbers. But he would have gotten a better negative if he did have the time.

You do realise that I was joking.