Digital BW, The Print

Hi there,

I am returning to 4x5 photography after a long absence and will 
develop Tmax-100 sheets in small tanks with D-76/T-max fixer. I will 
scan my negs on an Epson 3200 flatbed scanner (capture with 
SilverFast as 16-bit grayscale) and then work with the images in 
Photoshop, printing eventually with the ultratone inkset for the 
Epson 2200.

I would like advice on doing some testing to determine my best 
exposure index and development times. I do not have access to a 
densitometer. The rough outlines of my plan are to make 9 exposures 
of the Kodak Color Separation Guide and Grey Scale (Q-13).  I will 
make 3 exposures each at three different EI's – say 50, 100 and 150. 
I will then develop each series of low, medium and high EI's at 3 
different development times, starting from some base time then adding 
or subtracting 30% development time. (My normal agitation pattern is 
5 seconds every 30 seconds, where I lift my negative holder out tilt 
left, then right 45 degrees, and replace the negative holder back in 
the small tank). 

On a different, but related, note I am interested in ensuring that my 
critical plane of focus really is at the ground glass, so I am 
interested in suggestions on what kind of other targets I should add 
to my test scene to evaluate this.

Back to my basic question of EI and development time testing, one of 
my problems is I am not sure what to look for in the resulting scans –
 if I understand correctly the other posts I've read I should be 
aiming for thin negatives and not care about contrast as I can add 
all the contrast I want in Photoshop. For me this means I should tend 
towards a higher EI (I used to use 65 when printing from my negs), 
and perhaps shorter development times. Another more specific question 
I have is whether I would be better advised developing longer in a 
1:1 dilution of D-76, or shorter with full strength developer.

Any and all comments on a testing process/approach that will help me 
nail down EI and development times very gratefully appreciated.

David Meddings

Cross posted to large format photography forum and photo.net