View Full Version : ASA400 to ASA 800 - double development time?

19-Apr-2013, 09:44
Flog me as needed but if I shoot ASA400 film at ASA800, its a good starting point to just double my development time. I have read so many dev charts and I dream about numbers and ratios, brain is slightly fried...

19-Apr-2013, 09:51
Try to multiply by 1.5 instead of doubling.

Richard Rankin
19-Apr-2013, 09:54
Try here for your film/dev combo and probably get it right the first time:



19-Apr-2013, 10:07
Yea I have an odd ratio im toying with now, wanted to try it pushed and just wanted a rough idea where to start for time.

Terry Christian
19-Apr-2013, 10:44
1.25 x the original development time is usually a good start for a one-stop push. See the manufacturer's spec sheet on your film, as it might give you further information.

Peter Mounier
19-Apr-2013, 11:53
Tigger_six and Terry Christian are right in the ballpark. I used to increase dev. time 1.4x for 1 stop push with T-max. If the scene is contrasty to begin with try 1.25x, if the scene is flat, try 1.4x or 1.5x

19-Apr-2013, 17:49
The 1.4x rule of thumb is good for traditional films. T-grain films seem more sensitive to development time changes, so (for example) I add only 20% to TMY2 when going from 400 to 800.