B&W Underexposure: exposure or processing ?greenspun.com : LUSENET : Large format photography : One Thread
Hi, I have recently purchased a 5x4 tachihara and have taken a few pictures. However, they all seem to be of too low contrast. I downrate the film (usually to about half the asa on the box) and underdevelop by about 20% to retain shadow detail. The worst was HP5+ in rodainal. Why should this be, and what can i do in future. Does the problem lie in exposure or processing. Thanks
-- David Ivison (email@example.com), July 17, 2001
David: I rate HP-5 at 250-300 and develop normally in ID-11. The contrast in beautiful. What lens are you using? New? Old? Some of the older lenses can be low in contrast. Make sure the lens is clean. Still, I think you may be experiencing problems with development. Recheck your time, temperature, and agitation. Not enough agitatioon can kill contrast. Also, check your thermometer for accuracy. Hope this helps,
-- Doug Paramore (firstname.lastname@example.org), July 17, 2001.
The film development times given by Ilford are apparently for a condensor enlarger. If you're using a diffusion enlarger, you'll want to increase the dev time 15 or 20%.
HP5+ in Ilfosol 1:14 for 10.5 min with continuous agitation (sheet film in tubes) or 12.5 min with 10 sec agitation (roll film in tank) every minute prints well for me on a diffusion enlarger. This is a bit more time than Ilford recomend.
-- mike rosenlof (email@example.com), July 17, 2001.
Your too low contrast may be because you aren't giving it enough time in the developer. Holding back development trying to retain shadow detail isn't the waya to go. You get shadow detail through exposure and develop enough to get the highlights where you want them.
-- Dan Smith (firstname.lastname@example.org), July 17, 2001.
Moreover, what are you photographing. Does it have a full range of contrast. Remember, you will only get a full range of contrast if you photograph something that has a dark shadow in the shade and a bright highlight in the sunlight. Otherwise, you will not be photographing a full range subject. Obviously, you cannot get contrast when there is no contrast there. In addition, why do you blame just your development. have you had your meter checked. Your shutter checked. your thermometer checked. has your agitation changed. there could be alot of things causing your problem. best to get one foot through the door first, and then eliminate things one by one. do a film speed test (i.e. zone 1 at .10 above film base plus fog) once you get that, you can go from there.
-- Kevin Kolosky (email@example.com), July 17, 2001.
Besides all of the previous posts, bellows extension and/or filter factor may come into play and you will have to increase exposure to compensate.
-- Pat Kearns (firstname.lastname@example.org), July 18, 2001.
I had a similar problem with my crown graphic and when I converted to a c1 it still happened. Guess what? I had been putting the sheet film in upside down!
-- Echard Wheeler (email@example.com), July 18, 2001.