scottlaursen.com

All that changing the development time does is to alter the contrast (maximum density) of a negative.

 

Unless the film is severely underexposed (which 1 measly stop isn't), such a change in Dmax and 'slope' can mostly be easily compensated by using a different paper grade or in post-processing after scanning.

 

In short: An N+1 development will be plenty.

 

Here are the curves of 100 and 400 ISO films at different (push-pull) development times.

[ATTACH=full]1373519[/ATTACH]

You can see that the 'toe' of the curves stay quite firmly put on the X axis. Whereas if there was a true effect on the film speed the curves would move to the left with increasing development time.

 

In other words, nothing you do to the development time affects the speed of the film at all.

 

Thank you.

If you're happy with your results at 200 with the 400 time, then probably N+1 would be the way to go. If this is important, once in a lifetime work, then shoot and develop a test roll to see if you like the results.

thanks! It is not important lifetime work. I live in Michigan's UP and just have not seen the sun for weeks, so I thought I would give push processing a try for a bit most contrast.

I normally rate HP5 at 200 and develop per 400 times. I pushed it to 800, thinking development would be N+1, now I am wondering if it should actually be N+2 since I normally rate it as 200? Input is appreciated.

Looking for this hard to find module to fit my Noblex 150.

Please drop a message if you have one.

thanks

 

Were you able to locate one of these bad babies? I am looking for one as well.