Rodinal dillution rule-of-thumb..

Wirehead · Post by **Wirehead** » Fri Oct 20, 2006 1:32 pm

So I've started making the big leap from taking film to the developers to developing it myself. I want to make sure I adequately understand my process and the variations on it. Are there any "rules of thumb" for going between rodinal dillutions to generate a starting point development time? Say I see a time for 1:25... is there a percentage that will take me close to the roughly-equivelent time at 1:50?

Keith Tapscott. · Post by **Keith Tapscott.** » Fri Oct 20, 2006 1:41 pm

Wirehead wrote:So I've started making the big leap from taking film to the developers to developing it myself. I want to make sure I adequately understand my process and the variations on it. Are there any "rules of thumb" for going between rodinal dillutions to generate a starting point development time? Say I see a time for 1:25... is there a percentage that will take me close to the roughly-equivelent time at 1:50?

The development times for 1:25 and 1:50 for various films will be supplied with the developer.

Ornello · Post by **Ornello** » Fri Oct 20, 2006 2:44 pm

Wirehead wrote:So I've started making the big leap from taking film to the developers to developing it myself. I want to make sure I adequately understand my process and the variations on it. Are there any "rules of thumb" for going between rodinal dillutions to generate a starting point development time? Say I see a time for 1:25... is there a percentage that will take me close to the roughly-equivelent time at 1:50?

Look here:

http://www.digitaltruth.com/devchart.html

Wirehead · Post by **Wirehead** » Fri Oct 20, 2006 3:25 pm

Ah, that's not quite what I asked. But thanks.

For Fomapan 400, there's 1+25 and 1+50 times for E.I. 400. There's also 1+50 times for E.I. 800. There's no 1+25 time for E.I. 800, nor is there a 1+100 time for E.I. 400.

Obviously I cannot trust any timing that I haven't verified carefully with my pictures of George W. Bush and Bill Clinton sharing an intimate moment in the oval office and will need to run tests on my own, using the numbers given as a base..... But is there a way for me to close in on a reasonable starting point for where I should start my testing?

Fotohuis · Post by **Fotohuis** » Sat Oct 21, 2006 2:49 am

Fomapan 400 and Rodinal is a very grainy combination. Further this film is not so suitable for push processing which you can also see in the Fomapan 400 datasheet. http://www.foma.cz/Upload/foma/prilohy/F_pan_400_en.pdf

For some Fomapan film combinations you can look at:
http://www.fotohuisrovo.nl/documentatie ... tijden.pdf

and some examples in a para-amino phenol developer (R09 or Rodinal):
http://gallery.fotohuisrovo.nl/thumbnails.php?album=5

Wirehead · Post by **Wirehead** » Sat Oct 21, 2006 11:54 am

That also doesn't answer my question.

But incidentally, I haven't been worrying about grain ever since I moved from 35mm to 6x7.

So on another forum, I hear that one guy doubles the time when he doubles concentration, so if it's 10 minutes in 1:50, one should start the development time testing at 20 minutes at 1:100. That doesn't fully jibe with the datasheet, but can anybody come up with a counterargument?

Rodinal dillution rule-of-thumb..

Rodinal dillution rule-of-thumb..

Re: Rodinal dillution rule-of-thumb..

Re: Rodinal dillution rule-of-thumb..