Delta 100 in HP Combi Tank?

[timlayton]

I just tested some Delta 100 4x5 sheet film and determined my personal EI rating to be 80. The odd thing is that I used the normal development and agitation stated by Ilford which was 6 minutes with HC110 - B and I got N+3 which was shocking to me. I can't believe it was due to agitation causing these results. My best guess is that it may have something to do with the HP tanks or I may need to dilute +1 possibly (in other words instead of using 30ml(1oz) per 32 oz water to dilute +1 therefore using 15ml(.5oz) per 32oz of water. I would rather not guess if others have experience and I could at least get closer than then continue my testing.

My question. Is anyone using Delta 100 sheet film and HC110-B in a HP Combi Tank? If so, what have you found your normal development time to be? And then N-1 and N+1?


Thanks

Tim

[trexx]

My question. Is anyone using Delta 100 sheet film and HC110-B in a HP Combi Tank? If so, what have you found your normal development time to be? And then N-1 and N+1?


Thanks

Tim

I don't have a combi tank but have found that film charts are only a starting point and then only for roll film. Sheet film very much becomes dependant on the individual and technique used, be it trays, tank, tube or whatever. From my own experience with sheet film the time of 6 min. from the chart does seem long to me. Not N+3 long but long. But getting shorter makes for hard be consistent.

What I would do, is follow the procedure outlined in Way Beyond Monochrome for both HC-110 dilution B and dilution E.

TR

[timlayton]

TR, thanks for the reply. I was very surprised at the N+3 as well but I know it is right because I am using a 31 step tablet and densitometer to take the readings to plot the curve. I own "Way Beyond Monochrome" and will go take a look at it as you suggested. Based on some initial research others seem to think a further dilution from B will get me closer to normal development. The most consistent comment so far has been 10ml of concentrate to 1 liter of water and develop for 5 min following Ilfords agitation recommendation. I am going to keep digging before doing more testing. The great news out of all this is that I know exactly how to get N+3 with Delta 100 in a HP Combi tank if I want it...

Thanks

Tim

[Michael R 1974]

It sounds a bit odd, but not overly so. I have found in general the starting point recommendations from Ilford and Kodak range from quite accurate to wildly wrong, depending on the film/developer combo. I don't use Delta 100 in sheet film, but I have used alot of it in 35mm and just so you have an example, my Delta 100 N time in DDX, with full film speed, is 8 minutes. Ilford recommends 12 minutes. I found that time way too contrasty, and grainier too.