Originally Posted by Robert Ley
I've also been using the MI-DUP and finding much easier to work with than lith film. I experimented with lith for quite a while with diluted HC-110 and LC-2 developer. Lith is a beast to tame. I was trying all different methods to keep the contrast down, including extremely dilute developer and extremely subtle agitation (including brush development). I also found that edge development was exaggerated. Of course it depends upon your image but with lot's of sky on the edge of the image, I was finding unevenness of tone a real problem.
Also, the mid-tones would begin to get quite flat at the same time.
X-ray dupe film has been much easier to work with. It's almost the opposite to lith. I've been using dektol almost straight with short development times (3 minutes). The lith were up to 18 minutes!
I've replaced my enlarger bulb to a brighter 150w bulb and use a glass carrier because of the extra heat. This is cut my times down but still around 60 seconds at 5.6.
The main way to control contrast of the negative is altering your developer strength.
The dupe film is weird to work with though, totally opposite than normal film/paper. It gets confusing at times, especially when you start dodging and burning! dodging to darken and an area!
I'm still having issues with agitation. The images I'm working with have a white background, and keeping that consistent is not easy. I've started trying brush development which hopefully will help.
Personally, I would say, stay with the x-ray dupe film.