Long Exposures: Starting Point

[Alex Hawley]

I'm going to try some long exposures; basically, still lifes in a darkened room that will take several minutes.

Anyone have a good idea on a time to start with? 10 minutes, 15 minutes, 30 minutes? I'm using 100 or 200 speed B&W film.

[steve simmons]

What film? They do not all respond the same.

steve simmons

[Alex Hawley]

APX 100 or J&C Classic 200 Steve. I also have some Tri-X 320 if anyone has experience with it.

[Bill_1856]

Press 40, 1/100@f:8.0.

[Matt Miller]

I just shot a still life in low light last night with J&C200. Light readings were between EV1.5 & EV3.5 with an EI of 50 for the J&C200. I exposed the film at f32 for 1 hour, after reciprocity consideration. I developed today in F09 and the neg appears to have the right density (for me at least). If I were using something like Tmax, the exposure would have been around 12 minutes instead of an hour. I'm not sure about APX 100, but with J&C200, reciprocity can be a big deal.

[Brian Ellis]

I asume you're asking about reciprocity. There are basically two types of normal black and white film from a reciprocity standpoint, T Max and everything else. If your initial reading is 2 minutes and you're using T Max 100 then try 5 minutes. If you're using T Max 400 then try 6 minutes. If you're using anything other than T Max then try 12 minutes.

These times are based on a table handed out by John Sexton in one of his workshops and they've worked well for me using T Max 100 and HP5+. I've never used T Max 400 so I have no experience with the suggested time for it. Remember that when you get into five and ten minute exposure times you're not in a situation where perfect precision is important or even possible. It's almost impossible within reason to overexpose. An extra 15 seconds on top of a five minute exposure, or even an extra minute or two on top of a 12 minute exposure, will make very little difference. Also remember to adjust your developing times for the increase in contrast that reciprocity adjustments will bring about. If you use your normal development times with these kinds of increases you'll get the equivalent of an N+1 to N+2 development so you need to reduce your times unless you want the increased contrast.

[Christopher Condit]

Bracket in larger increments than you would ordinarily. I do some pinhole work that requires very long exposures, sometimes into the hours, and I routinely bracket by 2.5 stops, one down, and three or four up.

[Alex Hawley]

Thanks for all the suggestions so far. I made the first trial last night - exposed for 20 minutes. It was too much. Onward and upward.