Question about 8x10 closeup DOF and Time

[mark]

i dusted off the 8x10 because I found an interesting zucchini. I then watched this:


Kim said Edward’s pepper and shell were 6-8 Hour exposures! My question is this:
Is this long an exposure and minuscule pinhole f-stop necessary for maximum depth of field with close up 8x10?

My wife chopped up my zucchini for dinner so that model is gone but I would like to know for the future.

 

[tedr1]

Several things can happen with very long exposures: one of them is that when the light source is daylight the light can change as the sky brightness and sun location vary with the time of day, and this might be apparent in the image. Film experiences reciprocity failure, a one hour exposure does not necessarily produce twice the density of a half hour exposure and neither produces density proportional to that produced by "normal" brief exposures. If the lighting was available-daylight and indirect and indoors which all seem likely, the light level might have been deliberately reduced to extend the exposure time.

I believe there are some journals by Weston, perhaps titled day-books?, which may shed some light on this?

 

[Dan Fromm]

There are books on close up and photomacrography. Buy and study:

Lefkowitz, Lester. 1979. The Manual of Close-Up Photography. Amphoto. Garden City, NY. 272 pp. ISBN 0-8174-2456-3 (hardbound) and 0-8174-2130-0 (softbound).

Gibson, H. Lou. Close-Up Photography and Photomacrography. 1970. Publication N-16. Eastman Kodak Co. Rochester, NY. 98+95+6 pp. The two sections were published separately as Kodak Publications N-12A and N-12B respectively. Republished in 1977 with changes and without the 6 page analytic supplement, which was published separately as Kodak Publication N-15. 1977 edition is ISBN 0-87985-206-2.

Both are available used at very reasonable prices from sellers on abebooks.com, alibris.com, amazon.com, bn.com, ...

The only way to get good depth of field is focus stacking followed by image processing. Unfortunately this is nearly impossible with 8x10.

 

[wiltw]

I pulled out a FOV calculator and found...

1. a 645 camera with 75mm lens focused at 13" captures an area which is 6.0" x 8.0"
2. a 4x5 camera with 150mm lens focused at 14.8" captures an area which is 6.0" x 7.5"

Firing up Cambridge Color's Flexible DOF calculator, set to viewer acuity with 20/20 vision (the optometrist's goal for correcting your vision)

1. a 645 camera with 75mm lens focused at 13" results in f/4 DOF zone which is 0.08" deep.
2. a 4x5 camera with 150mm lens focused at 14.8" results in f/4 DOF zone which is 0.04" deep
3. a 4x5 camera with 150mm lens focused at 14.8" results in f/8 DOF zone which is 0.08" deep

IOW, the DOF is very similarly shallow for both formats and when the aperture is proportional to the format size increase it is 'the same'. So many photographers fail to understand the relationship of DOF is mostly linked to the SIZE OF SUBJECT as a fraction of the total frame, which is why shooting 135 format with 50mm at 10 distance results in 'same DOF' as 400mm at 80' when the aperture is the same for both lenses.!

 

[Vaughn]

I remember something in the Daybook about it. Exposed on the front porch -- something about the vibration of a passing truck causing some unsharpness in one of the attempts.

More than likely he was dealing with increased exposures due to bellows extension, on top of reciprocity failure.

 

[Doremus Scudder]

I used to shoot a lot of close-up still lifes on my dining room table in my Vienna apartment. It was rather dim; lighting only from skylight (no direct sun) through gauze curtains over a window on the wall some 15 feet or so away. On cloudy days I'd set up the shot, pull the darkslide, uncap the lens and leave for work. When I got back, I'd cap the lens and insert the darkslide. Exposures were in the neighborhood of 4-7 hours. Never a problem. Keep in mind that an indicated 30-minute exposure is only a few stops overexposed with a 4-hour exposure. Add to this the extra exposure you'd need for the reduced development required by such a long exposure together with reciprocity adjustment and the effective overexposure is even less. An 8x10 negative that is a few stops overexposed is still very printable. I imagine Weston tended to err on the side of overexposure when working close up, similar to what I do. Couple that with the fact that his films were slower, had worse reciprocity failure than today's films and that close-up work with an 8x10 needs a lot of bellows extension compensation and it's no surprise that his exposures ran several hours.

Best,

Doremus

 

[John Koehrer]

Keep in mind too,The film was slow and E.W. judged exposure by "feel" and a lot of experience
with his processes.
Considering that none of his lenses would stop down to anywhere near pinhole size, Oh My!

 

[Ian Leake]

A long exposure is almost inevitable with an 8x10 1:1. Only more light, wider aperture or faster film will shorten the exposure; and all of these introduce other problems. Bear in mind that if you’re contact printing, then when using DoF calculators you can get away with a larger ‘circle of confusion’ (https://en.m.wikipedia.org/wiki/Circle_of_confusion) because you’re not enlarging.

 

[Dan Fromm]

A long exposure is almost inevitable with an 8x10 1:1.

Eh? Wot? What does 8x10 have to do with anything?

I ask because for all formats effective aperture at 1:1 is 2*the marked aperture. Exposure time on 8x10 at 1:1 will be the same as exposure time on all other formats.

 

[Ian Leake]

Exposure time on 8x10 at 1:1 will be the same as exposure time on all other formats.

This statement is only correct if all variables remain constant, but given normal working practices with large format it's misleading. For a start, you're likely to be using a long focal length lens (much longer than smaller formats). You're likely to be shooting at f/90 or above. You're likely to be using a slow-ish film. Of course your bellows will be considerably extended for 1:1 giving a 2 stop reduction of light. All these conspire to make a long exposure almost inevitable.

 

[Dan Fromm]

This statement is only correct if all variables remain constant, but given normal working practices with large format it's misleading. For a start, you're likely to be using a long focal length lens (much longer than smaller formats). You're likely to be shooting at f/90 or above. You're likely to be using a slow-ish film. Of course your bellows will be considerably extended for 1:1 giving a 2 stop reduction of light. All these conspire to make a long exposure almost inevitable.

Stuff and nonsense. A shot taken at 1:1 at f/90 set, f/180 effective, is at the very edge of acceptable sharpness for contact printing, probably over it, and is useless for enlarging.

It pains me to say it, but if the OP wants decent DoF at 1:1, the best approach is digital with focus stacking and a composite final image.

 

[Ian Leake]

Stuff and nonsense. A shot taken at 1:1 at f/90 set, f/180 effective, is at the very edge of acceptable sharpness for contact printing, probably over it, and is useless for enlarging.

It pains me to say it, but if the OP wants decent DoF at 1:1, the best approach is digital with focus stacking and a composite final image.

Words like 'decent', 'acceptable', 'best' and 'useless' are subjective and over-used. The OP asked a question about the practicalities of using an 8x10.

Lots of people have made fabulous, emotive close-up photographs using 8x10 cameras. And they've tended to use long exposures for all the reasons stated above.

Weston's peppers and shells have plenty of sharpness for their purpose. And he didn't need a digital camera, focus stacking and other digital techniques to achieve it. But he did use a long exposure.

 

[Dan Fromm]

Ian, that was back in the dark ages when men were men and so were women. Shooting close up follows the same rules and faces the same problems for all formats. There's nothing special about 8x10, except perhaps practical matters like carrying the gear long distances.

As for evaluating image quality, there's reason to believe in an objective reality that nearly all people agree on. Do a google search on Kodak and "subjective quality factor." The term SQF is slightly unfortunate, but the results of Kodak's research on acceptable print quality seem to be correct and universal.

 

[mark]

Contact printing, eventually.
No desire to use my digital stuff for this
Weston's pepper and shell look spectacular to me

Long exposures it is. Now I have to try and wrap my head around developing with reciprocity in mind.

Off to read up on reciprocity.

 

[Jim Noel]

The fastest film Edward ever had at his disposal had a Weston (no relation) speed of 50. Many in his time were in the 10-20 range.

 

[DREW WILEY]

I've done lots of 8x10 closeup work. Typically around 8 to 15 sec. Learning good depth of field skills is an involved topic. It's not just about stopping down. View cameras allow intelligent movements. If you enlarge, it gets counterproductive to stop further down than f/64. Contact printing will tolerate smaller stops. However, the point is to get an interesting image. At what point does something really look compelling on the ground glass? Some selective focus might be needed; but don't think of that as a liability. Use it creatively. I've never used a depth of field table in my life; and I've made quite a few big prints with immaculate detail where it counts. You do need to know the bellows extension factor per the exposure, as well as the reciprocity characteristics of your chosen film.