over exposing film

I have been advised of a technique of over exposing your film by 3 or 4 stops

and then underdeveloping the film when processing. This is supposed to expand

the range of the film and bring out detail in the shadows. Under developing the

film is supposed to stop the highlights from blocking out. Has anyone used this

process and if so can you provide any hints. Thanks Bill

Bill,

 

Did you ever use Diafine? This will do what you want with no hassle.

Many people, me included will overexpose (by the iso speed) by a stop and reduce development. On bright contrasty days this gives maximum shadow depth. Anything else is going to lead to huge depth of field/camera shake issues. Doesn't sound a good idea to me, besides with above technique you get more than enough "range".

Yes, it is the basis of the Zone System.

 

For example, in dull, overcast conditions where there are no shadows, I use the film at rated speed and dev as per manufacturer's recommendation (or thereabouts). If the light is hazy and there are soft shadows, then I down rate one stop and reduce development time by one-third. In bright sun with hard shadows, I downrate 1 1/3 stops and reduce dev time by 45 percent.

Film speed will drop with shorter and shorter development times. So work out your times/exposures before doing anything you can not repeat.

 

One stop more is common for small format users who look for maximum shadow detail in average scenes. Reduce development 20%.

I have exposed Tri-X and HP5+ @ 50 before, which is a 3-stop pull from box speed. I process it in D76 1:1 for about 6:30. I used that speed because it was noon on an extremely sunny day on a cobble stone street with lots of highlights and harsh shadows everywhere. It was also the only speed that would let me use an aperture wider than f/8 as well.

 

I typically reduce development by 20% for each stop pulled.

 

I personally didn't like the results I got with HC110 for this type of over-exposure, but the D-76 1:1 turned out nicely.

It's common to go one stop under the published ISO speed, to the point where it should almost be the preferred starting point. The danger in going beyond that and cutting development too far is you can lose the contrast of the midtones and your shots will have no pop, snap, brilliance, or whatever term you choose. IMO, it's best to *not* think in terms of over or underexposure, but think about the range of the scene, the film, and the paper. That's what the Zone System is all about. Even if you don't actually use it, the concept is valuable. The terms over and under exposure are too simplistic for what's really going on. If the scene is flat, there will be a range of exposures that qualify as correct. If it's very contrasty, there may be no good compromise.

It's hard with 35mm. The whole roll needs to be shot under the same light conditions. I shoot Tri-X @ 200: develop at 10.5 minutes in HC-110 dilution H, with 30 second agitation to start then 3 inversions two times, spaced. This is a compromise on any flat low contrast shots but the information is there and I have to add contrast with PS.

Ron, if you come back here, would you say your 20% estimate can be applied to non-solvent developers, or does that matter? I ask because I'm having trouble adjusting dev times with PMK, whereas with Xtol et. al. 15 or 20% always gets me close.

All this over and under exposing is really unnecessary if you take an incident reading in the shadows and expose according to that. Always in the shadows, regardless of whether it's sunny or foggy or whatever, and adjust development time according to the scene and the lighting conditions.

 

The little difference you get in shadow density with different development times is negligible according to my (limited) experience, but if you want to fuss around for 1/4 or 1/3 stops, which I hardly believe would yield any visible difference in black and white film, you can do that.

 

If you take an average reading with a matrix meter, of course you'll have to compensate in sunny weather.

I agree. What people are really telling you is not to over expose, but to meter on the shadows. I regularly move my shadows up to Zone V (4 stops "over") and still get highlights in my TMAX. I was having a hell of a time printing until I read an article recently that suggested doubling the exposure under the enlarger and halving the time in the developer. This gave me the best prints I ever had, and eliminated dodging and burning. I'm still trying to figure out why this practice is n't more recommended.

pulling?