L-O-N-G Exposure Technique…

[Scott Rosenberg]

Hey guys,

For an upcoming project, I’m going to be making some very long exposures – well, very long for me, at least. On the short end, things will be from 2-15 minutes. On the long end, things will be from 15 minutes to 1-hour plus. I’ve already decided to use Fuji Acros, and according to the data sheet, no exposure compensation is needed up to 2 minutes. For 2 minutes to 15 minutes, Fuji recommends opening the lens ½ stop. A few questions…

What exposure changes would you recommend for exposures north of 15 minutes?
Should I develop the film normally?
Do you recommend anything at the time of capture, such as a filter, to recover some contrast?

Thanks for any and all suggestions – this is new territory for me!

[CG]

Hey guys,

For an upcoming project, I’m going to be making some very long exposures – well, very long for me, at least. On the short end, things will be from 2-15 minutes. On the long end, things will be from 15 minutes to 1-hour plus. I’ve already decided to use Fuji Acros, and according to the data sheet, no exposure compensation is needed up to 2 minutes. For 2 minutes to 15 minutes, Fuji recommends opening the lens ½ stop. A few questions…

What exposure changes would you recommend for exposures north of 15 minutes?
Should I develop the film normally?
Do you recommend anything at the time of capture, such as a filter, to recover some contrast?

Thanks for any and all suggestions – this is new territory for me!

Acros is supposed to keep much of it's sensitivity waaaay out. Try maybe a stop at an hour.

If you can, do preliminary tests at the times you will be using to confirm how things work for you.

Generally long exposure tends to bump up the contrast with most films, so don't mess with development unless you see a bump up in contrast you don't want.

Filter only to do just what you would do in shorter exposures.

C

[Ron Marshall]

See the following links. There is a curve fit that you can plug times into to get a good estimate of the reciprocity corrected time:

http://silvergrain.org/Photo-Tech/reciprocity.html

http://home.earthlink.net/~kitathome/LunarLight/moonlight_gallery/technique/reciprocity.htm

[Kirk Keyes]

Generally long exposure tends to bump up the contrast with most films,

This statement should be true with all films once you get into the real of reciprocity failure. At and given expsoure, the area of film receiving less light will have more reciprocity failure when compared to areas recieveing more light. This means the shadows will be underexposed more than the highlights and that's what increases the contrast.

Looking at Kit Courter's data link to above, you should need only about 50% more exposure at 1 hour with Acros.

[Mattg]

I'd try a few films if you have the time. Delta 400 is very good at night. Acros has a very particular look in night exposures, almost like day, I prefer Delta because the exposures still look like night.

It would help to know what sort of scenes you'll be attempting, urban landscapes at night require very different techniques to a full moon away from artificial light.

[Scott Rosenberg]

hey guys... thanks for the inputs. sounds like i'll start with acros and open up 1/2 a stop... normal filtration and development and take it from there.

[eddie]

hi scott,
i use the pinhole designer to get my reciprocity info for my pinhole exposures. arcos is listed as a film so youy just "plug and go" and you will have some very close times. i do reduce development a bit also. my favorite film is foma100. it has terrible reciprocity! when i use it i use hc110 dil g for 18 min at 68 with agitation every 3rd min. works well.

i have been using tmax100 recently also. it is a "fast" film similiar to arcos(acros is difficult to get in 4x5 cut) and i have been getting good results using the same 119:1 dilutions. i am still working on perfecting it. i am using the digital truths times and doubling the dil h times. i probably need to reduce dev.a tiny bit but the negs are printing fairly well. (with foma i get negs that scan and print very well. with the tmax the negs print well but my scanner hates them. [my scanning abilities are very poor so this may be the reason!])

eddie

[keithwms]

For long exposures in colour I like fuji 64T. Referring to this (http://mkaz.com/photo/tools/reciprocity.html) site, 64T isn't horrible.

But for b&w acros indeed looks great. It looks so good that I guess you might simply give it a stop extra and tone the neg a bit if necessary.

[Jim Noel]

T-Max 100 is not similar to Acros in film curve, color response, or reciprocity characteristics, and possibly other areas. In addition, if you ever intend to use the negatives for any of the alternative printing methods, TMax 100 will not work because of the built in UV filtration.