Tone reproduction is fine. There isn't really a very straight region (like
TMax film), but as long as you are not doing reprography where you try to
match the original to the final print, separation is ok if you place the
exposure carefully.
Exposure range is short. It is about 7-9 steps of the 21-step step tablets. If
your original has a longer density range, you might have to worry about this.
Even if the density range of your original is short enough, the short exposure
range of lith film means exposure must be carefully control, otherwise you
will lose highlights and / or shadows.
If you are developing for high density, there usually isn't much problem. You
can use diluted Dektol, and the resulting images are usually pretty even.
If you are developing for low density (espeically for very low density for
single-coat gum, for example), there might be some physical/mechanical
problem. For example, with Dektol 1:7, the contrast is still way too high for
me. If you try to reduce development time, you might run into problem of
evenness. You can try higher dilution, but I found that I needed 1:20 or more.
Now you might run into capacity problem because if you have 150 ml stock, you
will need about 3 liter of water, so it is hard to agitate properly. If you
don't have enough stock, you might run into problem of exhaustion, buffer
capacity (you will see mottles, streaks, etc.) especially if your image has a
lot of high density areas (these areas used up the developer very quickly).
Presoak helps, but you still have to observe the capacity requirement (must
have enough stock).
One solution is to use a softer developer, for example, I have tried D76 1+3
successfully, and Judy also had success with glycin developer. With low
dilution, I can easily have 250ml stock + 750 ml water, thus fulfilling the
requirement of capacity and longer time. I have used D76 1+3, presoak in water
for 3 minutes, and develop for 4-5 minutes, and you will get very nice, even
negative (or positive).
Remember that you are using the developer at near exhaustion, so capacity is
important. In other words, 100ml + 300 ml H20 is different from 250ml + 750
ml H20. Both are 1+3, but the first one does not have enough stock.
My next tests will be developing using home mixed formula. I will try some
soft developer, divided development, and maybe even create a formula. I will
post my result here or write an article in the journal of PFP.
Dave