dkwrt200
Dear forum members,
Are there any guidelines on the minimum amount of developer to use? For black-and-white roll film development, I prefer to use my old Rondinax 60 daylight developing tank. It’s a wonderful piece of kit – why don’t they make things like this anymore? Loading in daylight without sealing the tank, no dust, no spills, no loading problems! What’s more, it only requires a batch of 130–150 ml of developer.
This means that with Rodinal at a 1:50 dilution, just 3 ml of chemical is needed, and a 125 ml bottle yields a whopping 41 films, which keeps development costs pleasantly low.
Now, I seem to vaguely recall a warning from Agfa that a minimum of 10 ml of chemical must be used for an RF. Of course, you can go below that, but where does it really get tight?
With A49, especially if a few films have already been processed, I use the half-litre tilting tank to be on the safe side. Otherwise, with Ilford/ADOX CHM 125, efke 100 and Foma, I’ve had nothing but positive experiences so far using just 3 ml in the Rondinax. Only one Lucky failed once, but that may not have been due to the small amount of chemical.
Actually, I’d prefer to stick with Rodinal 1+50 (or R09) for the Rondinax, but I’ve got a few shoots coming up with efke 25. Will the amount of developer still be enough for that?
Best regards,
Rainer
fotohuisrovo
No, that’s not enough. What’s more, with this minimum volume, you’re at the mercy of the subject matter on the film. That’s obviously very risky.
The official minimum volume for Rodinal is 10ml per roll of film (135-36 or 120 roll film). We know from several tests that 5–7ml per roll of film is ALWAYS just about manageable.
So: Switch back to 1+25, as there’s no problem with that. Yes, the downside is slightly less contrast, but the grain will therefore be less of an issue.
All developers have this: e.g. AM74/LPSupergrain/RHS: 20ml per film from a 1+7 dilution. Can be used up to 1+19. 1+9 will probably just about work with the Rondinax 60.
By the way, I often use Rodinal 1+100 with a Jobo 1540 (up to 1 litre). So no problem. :rolleyes:
Best regards,
Robert
Gast
Regardless of the dilution, the film requires a minimum amount of developer. This can become a problem with small batches and higher dilutions. If the manufacturer specifies a quantity sufficient for 10 films for a 1-litre batch, there should still be 100 ml of developer remaining even at higher dilutions. At some point, further dilution ceases to make sense due to the ever-increasing development time. It is often sensible to extend the time through dilution if the development time can only be estimated. If you develop for three minutes longer at 15 minutes, this has less of an impact than with a development time of 5 minutes.
