A b/w development question

[Pfiltz]

I've never really shot anything over a second or two with regard to exposure times. I use Arista EDU for my 5x4 film, and have the reciprocity chart for it with regard to exposure times.

When it comes to development, do I have to change my usual 6 minute development time with my current developer which is some old D76, or is there a chart somewhere, that I should be looking at to use for images that may have been shot at 5 minutes or so longer?

TIA

[Corran]

Generally you should use N- development when dealing with reciprocity. The lower values are affected more, so it increase contrast.

As a general rule of thumb in my case (usually T-Max 100), I do 1 "stop" of pull (N-x) per stop of reciprocity compensation. So in other words - 1 stop correction, I'll develop N-1. 2 stops of correction, N-2, etc.

[Pfiltz]

Sorry Brian, but can you dumb it down a bit more for me. I don't shoot/develope a lot of film. I shot my first macro shot last week, and guessed at my fstop for that bellows factor, and got lucky ... ;)

[Corran]

Um, let's see...

Let's say your value range looks like this normally:
http://www.oceanstarproductions.com/photosharing/recrange1.jpg

The lower values get affected by reciprocity more, while the higher values don't, so they get overexposed. So after a reciprocity correction of say, 3 minutes to 6 minutes (1 stop), your values look like this:
http://www.oceanstarproductions.com/photosharing/recrange2.jpg

So you need to pull the development ("develop for the highlights," as per Ansel Adams). So if your "normal" (N) development time was 7 minutes, and your time for ~15% less contrast is 6 minutes, you would develop for about 6 minutes in this situation. I'm just pulling these numbers out of thin air so don't quote me.

Does that make any sense? If not, please tell me what you're not getting. Also, this has worked for me, but there may be other ways to go about it.

[Pfiltz]

Thanks... I "think" I understand what your saying. First off, I've never pushed/pulled developments... All I've ever done is just develope based on the Mfg. suggested times/temps. ;)

I've never gotten into film at those depths. I know when I'm shooting, I meter for the shadows, and when I was printing, I printed for the highlights. That's about all I know with regard to film/development/printing...

Maybe I'll shoot two pieces of film at the same times [long exposure], and change my development times to see how they differ.

[Corran]

I see! To start I would just knock off 10-15% on your time and see what you get.
BTW, the text didn't work so I fixed my "illustration" on the previous post.

Alternatively - you could try semi-stand development if you wanted. That's another way I've tackled such an issue.

[Pfiltz]

Thanks buddy. I appreciate the insight.

[Corran]

No problem, good luck, hope to see your results in the Image Sharing Forum!

[Toyon]

Thanks... I "think" I understand what your saying. First off, I've never pushed/pulled developments... All I've ever done is just develope based on the Mfg. suggested times/temps. ;)

I've never gotten into film at those depths. I know when I'm shooting, I meter for the shadows, and when I was printing, I printed for the highlights. That's about all I know with regard to film/development/printing...

Maybe I'll shoot two pieces of film at the same times [long exposure], and change my development times to see how they differ.

I never found a manufacturer's suggested time that worked for me. Experiment. As for long exposures, remember that you exponentially multiply the possibility of weird artifacts and errors.