APX 100, two different EI on same roll

I have finished about a dozen frames in a roll of APX 100 at ISO 100, only to realize

afterwards that it had started its career at ISO 50. That's more than one stop, right? What

would be the best EI to pick to process it in etiher DDX or Xtol? Thanks.

The box ASA is almost ALWAYS overated by a stop anyways.

Let's say I'll go a little bit over EI 50, like 15 seconds more. How's that?

Develop as if the whole roll were 100 ASA. Your 50 ASA frames will be a little dense and contrasty but they'll print.

APX 100 is reasonably forgiving. I think it'll handle a little underexposure better than it will overdevelopment. I'm with the advice to develop for EI 50 and let the EI 100 frames take care of themselves.

 

Or - giving the advice I'd take myself - develop for the most important frames, regardless of what the exposures were. If I expose the first half of a roll of Tri-X at 400 and am forced by circumstance to shoot the rest at 3200, well ... if the first half was a bunch of boring architectural studies that I could go back and do over while the second half is of Paris Hilton caught streaking ... I think I'll develop for the more unusual stuff.

hi Olivier,

 

two bath developers are great for this situation - esp. d23 with alkaline

afterbath.

 

or

 

 

partial stand development with diluted developer eg. rodinal 1:100 normal agitation

for first 5 minutes ( agitate for first min. then 10sec per min ) then stand for 20 min. this

with ensure that the highlights remain within printing range and good tonal separation.

i've used this technique combining daylight and nighttime exposures with good results.

 

hope it helps . gonzalo.