Very small apertures, long exposure & subject movement :-)

greenspun.com : LUSENET : Large format photography : One Thread

When using the larger cameras I find myself using really small apertures, on the order of f/256 and smaller. With bellows extension of 3-5 times the focal length I am getting exposures of a day or so with some things. I can keep some of the plants from blowing in the breeze by tenting, but how do I keep them from growing during the exposure and blurring it?

Is there a mathmatical equation or formula, or a way to keep them sharp as they grow? Or am I just out of luck? Or possibly by shooting down on the subject can I somehow control the film bowing out in the center to counter act the focus change as the plants grow up toward the lens & film? Or should I just stick to slow growing or dead plants & keep the problems at a minimum?

-- Dan Smith (shooter@brigham.net), February 04, 2001

Answers

Response to Very small apertures, long exposure & subject movement

Dan,

Have you tried feeding your plants some "Phen-Fen"? Just kidding. Can you use flash to freeze your plant movements/growth, and thus shorten your exposure time?

-- Geoffrey Chen (DB45TEK@AOL.COM), February 04, 2001.


Response to Very small apertures, long exposure & subject movement

Well there you are. Now you've discovered why LF photographers prefer to photograph either the Bristlecone Pines or large treeless monoliths.

-- David Goldfarb (dgoldfarb@barnard.edu), February 04, 2001.

Response to Very small apertures, long exposure & subject movement

Go with the flow. Our photographs are apt to become more interesting.

-- David Stein (DFStein@aol.com), February 04, 2001.

Response to Very small apertures, long exposure & subject movement

Hi Dan, at f/256, do you notice any diffraction? Can you shoot through that small of a hole without getting some diffraction blurring? Best, David

-- david clark (doclark@yorku.ca), February 04, 2001.

Response to Very small apertures, long exposure & subject movement

Even when plants aren't actively growing, they move around a lot, which makes time lapse movies so interesting. The motion can be considerably slowed (I don't know if completely stopped) by chilling the air inside the tent with a little dry ice, and mantaining constant lighting on the outside of the tent (no direct sun, for example).

-- Bill Mitchell (bmitch@home.com), February 04, 2001.


Response to Very small apertures, long exposure & subject movement

photograph rocks and peeling paint only. maybe vegetables, though I think shrinkage or swelling might be a long-term problem.

can't you add a Moose Peterson EI booster filter and lower those ungodly exposure times?

-- daniel taylor (lightsmythe@agalis.net), February 05, 2001.


Response to Very small apertures, long exposure & subject movement

I think licehn may the the answer for you - fits the bill perfectly. Could be a real nich market for you there.

-- Tim Atherton (tim@KairosPhoto.com), February 05, 2001.

Response to Very small apertures, long exposure & subject movement

Either shoot artificial plants or use liquid nitrogen to freeze them. When they thaw, they'll be guarenteed to stop growing. To solve the exposure time problem, only shoot in Alaska or further north from about June 21st to September 21st.

-- Chill Wills (wayupnorth@brrrr.com), February 05, 2001.

Response to Very small apertures, long exposure & subject movement

What Colour Correction filter do you have to use for a 12 hour exposure Dan?
Or is the Heliotropic blur so bad that you can't see the colour?
You could always develop the technique, and make a feature of it, like Canaletto. If you look at his paintings, he painted the shadows as they were at the time his brush was on the canvas. So one part of the painting is in morning light, and another part shows late afternoon.

-- Pete Andrews (p.l.andrews@bham.ac.uk), February 05, 2001.

Response to Very small apertures, long exposure & subject movement

Or you can let me take care of your plants. That'll make sure they don't grow any more!

-- John H. Henderson (jhende03@harris.com), February 05, 2001.


Response to Very small apertures, long exposure & subject movement

You might try photographing cactus, drift wood, or aloe plants.

-- Ken Burns (kenburns@twave.net), February 05, 2001.

Response to Very small apertures, long exposure & subject movement

You are very funny man Mr.Smith! HA!HA!HA!

But we haf vays of making you talk.

-- Ellis Vener (evphoto@insync.net), February 05, 2001.


Response to Very small apertures, long exposure & subject movement

after rereading your post, it seems the answer is quite clear. the problem is that you have been smoking the plants before attempting to photograph them. try photographing first, then smoking, and see if results improve.

-- daniel taylor (lightsmythe@agalis.net), February 05, 2001.

Response to Very small apertures, long exposure & subject movement

This is a wonderful post since I can relate so well with it; it made me laugh out loud. I shoot slow film, small apertures and up here in Rochester NY it's usually overcast. I often shoot rocks but occasionally I complain to my buddy that I swear the blur on my negs is due to continental drift – so I wouldn’t consider rocks safe to shoot either.

Perhaps liquid nitrogen freezing would help.

-- doug mcfarland (junquemail222@yahoo.com), February 05, 2001.


Response to Very small apertures, long exposure & subject movement

Continental drift???!!! I had not factored that one in. Darn, it is always something. I had figured on the rising of the mountain ranges, especially when photographing in the Sierra Nevada range, which rises about an inch a year. I put the camera on a big tripod that has a rising center column an extend it a few millimeters & as the exposure progresses I let it slide down about 1/64 millimeter per hour of exposure in compensation for the rise. So far I think it works.

Then, to counteract the earths rotation I alway face the camera so I am loading the sheet film into the camera back in the opposite direction just in case the subjects lean the other way due to the spin. So far it seems to work OK.

But continental drift? Darnit, I knew there was a reason some images didn't come out right.

This stuff is so complicated. Never had these problems with 35mm. Maybe I should get the new AutoEverything cameras? I think they have computers built into them so they compensate for all this stuff. I wonder if they have earthquake sensors to compensate for the shaking? I did lose a good image one time as I pressed the shutter just as a nice temblor hit.

-- Dan Smith (shooter@brigham.net), February 06, 2001.



Response to Very small apertures, long exposure & subject movement

Dan: Most APS cameras automatically correct for the Coriolis force caused by the Earth's rotation. With large format, you have to do this manually. Carry a small pendulum to do the calculations. Moving to Mercury would help. Solar irradiation is much higher there so you can use slower film and shorter exposure times. Plants tend to vaporize quickly there so you will have to compose quickly.

-- Glenn C. Kroeger (gkroeger@trinity.edu), February 06, 2001.

Response to Very small apertures, long exposure & subject movement

While were on the subject you might also watch out for blur because of enlargment/contraction of objects due to temperature change. If you shoot rocks like a previos posted does, you could probably want to have a flame thrower with you to keep the temperature constant. You could aso try this technique if you shoot portraits but it could have some slight side effects.

-- Sorin Varzaru (svarzaru@bigfoot.com), February 06, 2001.

Response to Very small apertures, long exposure & subject movement

Whatever you do stay away from the rocks at the racetrack in Death Valley. On second thought maybe...

-- Jim Galli (jimgalli@sierra.net), February 06, 2001.

Response to Very small apertures, long exposure & subject movement

This is a ridiculous question and lots of ridiculous answers, overcomplicating the situation. The simplest thing would be to put a pair of 0.90 neutral density filters together. Normally, this would increase exposure time by a factor of 64 times (6 stops). However, if you use a reversing ring and put the filter BACKWARDS, it should reverse the effect and bring in extra light, reducing your exposure time by a factor of 64. So a 12 hour exposure will go down to about 11 minutes. Problem solved! Be careful not to use too much reversed neutral density as it could cause a fire in your camera.

Alternatively, if you don't want to spend the money on ND, there is another obvious way out. Plants depend on sunlight for their growth. So if you are worried about plant growth during exposure, MAKE THE EXPOSURE AT NIGHT!

(Disclaimer to novices: this is A JOKE)

-- Bill C (bcarriel@cpicorp.com), February 06, 2001.


Response to Very small apertures, long exposure & subject movement

What a bunch of maroons. Everyone knows about using reversing film. It takes care of all those problems. lumberjack

-- lumberjack (james_mickelson@hotmail.com), February 06, 2001.

Response to Very small apertures, long exposure & subject movement

How about Crossbow. If you just carry a bottle with you, it may scare the hell out of 'em.

-- neil poulsen (neil.fg@att.net), February 07, 2001.

Response to Very small apertures, long exposure & subject movement

I'm having a similar problem with extended times, although my problem is from extended development. My favorite developer is Rodinal diluted 1:20,000. You should see the edge effects you can get! What I do is stand develop in a sealed 55 gallon drum for one year, or two years for N+1. Every month or so I give the drum a kick for agitation, and at the half way period I roll it down the yard. My problem is rust. The drums deteriorate during the development period. I've tried plastic, but too much oxygen gets in ruining the developer, and I had one crack open and fog the film at the 10 month period. How do the rest of you solve these problems with your dilute developers?

-- Erik Ryberg (ryberg@seanet.com), February 07, 2001.

Moderation questions? read the FAQ