Delta Reciprocity

[steveo_mcg]

Has any actually tested Illfords reciprocity charts for Delta? I find it hard to believe that they're exactly the same as the traditional emulsions.

 

[wickerman]

Howard Bond carried out some tests, see here

 

[ChrisR]

Interesting. If I interpret that correctly (and I've never used tables like that before), then apart from Tri-X the indicated exposure needs to be over 30 seconds before there is more than a one-stop equivalent difference in the exposure time...

 

[RaglanSurf]

@ChrisR Completely off topic but Chris did you get my recent PM's? Or have you just decided to ignore me completely?

 

[ChrisR]

Yes (But to which question?)

Sorry, been all of a dither but will reply now.

 

[steveo_mcg]

Howard Bond carried out some tests, see here

So Illfords are overly concentrative. Drat, just when I was happy handing over thoughts of reciprocity failure to the app, it turns out the app uses Illfords data. I suppose I'll need to do my own testing Mr Bond's research doesn't cover Delta 400 that I can see.