A method I found on http://www.apug.org and am using since then goes like that: take a 5 – 10 cm piece of the film you want to test. It shall be completely exposed to light. Take 50 – 100 ml of the developer you would like to use and pour it in a glass. Put half of the film in the developer and start the clock. First, the part of the film in the developer will become lighter and lighter. As the time goes, the developed part of the film will get darker. At the moment when wet and dry parts get similar at their density, stop the clock. The time, in seconds, multiply by 20. This is you development time for this film and this developer in seconds.
After a discussion on www.apug.org (now www.photrio.com) that this method is not a trustworthy one, I feel like you shall know all opinions there. Here is the link to the thread:
https://www.photrio.com/forum/threads/any-truth-to-this.166454/#post-2166295
4 Comments
No, it doesn’t work that way. No matter what you do it will still be a wild ass guess.
Hello Fred–
As I am testing a lot of (technical) films that are not listed in massive dev chart I use this method for close approximation and starting point for development. If you use a different method — please let me know, I would appreciate it!
Best regards,
Vesselin
Vesselin
Does this method work for you? Someone posted a link to this post on Apug recently. If you have a membership there, can you post information about your results?
Many thanks
Stevie B
Dear Stevie–
It worked in the beginning, when I was testing combinations of films and developers that there is no information about (Gevapan 30, ORWO TF-8, ORWO DK-5, etc.). I tried it two – three times to get an idea about the starting point for experiments. I am not saying this method would give printable results. It might have been a total coincidence, I was very beginner at this time. I remember I came across this method on APUG, but have seen it on other forums and FB groups. I will check my notes further and will publish the sources.
Thank you for your comment! I will check the discussion on APUG.
Best regards,
Vesselin