Delta 100 contrast problem

I developed two rolls of Delta 100 at ISO 100 this morning in Xtol diluted 1:1. My filtered faucet water temp read 75 degrees, and Kodak's data sheet instructed me to develop it for 7 and 1/4 minutes at that temp. Both rolls had somewhat of a lack of true contrast in that there were no deep blacks or bright whites on the negs. Thus, they were somewhat flat.

I then went to Ilford's site and clicked on the PDF for Delta 100. They listed no development time re 75 degree water, but their recommendation at 68 degrees was 7 1/2 minutes, only 1/4 minute more than Kodak's! I now, thus, see the mistake to be Kodak's recommendation of 7 and 1/4 minutes, since a 1/4 minute difference between them and Ilford makes no sense in terms of getting acceptable contrast at the higher temperature.

Does anybody have a workable development time for Delta 100 at 75 degrees?

I use Ilford Delta 100 for most of my B&W work and develop in a Jobo CPP2.
The developing times I use alter very little, no more that 20sec. depending on the contrast of the scene. I expose Delta 100 @ asa 125 not 100.

I use one temperature, that recommended by Ilford; 20 Deg. 'C' or 68 Deg. 'F'

I am unable to comment on your developer times as I use Aculux 2 only, which is a one shot developer for recommended a dilution of 1:9. With this soup my time is 9 minutes +/- 15 Sec. I get a full tonal range.

Nevertheless, your time for the increase should be about right to get a good range of tone.
Have you checked all other parts of the developing operation such as dilution and agitation?

This combination is used by me for all formats from 5X4 to 35mm, I have never found just cause to change it over the last ten years or so.

I think it wise to make a real effort to get your developer temp. spot on 20 Deg. C, and use that as a sort of control sample for any other alterations.

Delta problem

Thank you for your thoughts, Stan. I scratched my head, hoping to prompt a memory of something that might have gone awry, but I found no answer. I took a nap this afternoon and, upon getting up and again giving the experience a clearer thinking basis, I suddenly remembered I had taken a 1 liter container of pure Xtol out of my refrigerator, poured 8 ounces of it into a graduate, added 8 more ounces of 75 degree water, and immediately poured the mixture into my 16 ounce stainless steel tank containing the two rolls of Delta 100. Aha! I had reduced the 75 degree water temp to the temp of the refrigerated Xtol! Boy, I've never made a silly mistake like that before but, fortunately, I learn from my oversights and mistakes and I'll never err in that fashion again. Happy shooting, processing, and printing, Stan!

Terry

Another thing is that perhaps 8 oz for two rolls (~120 ml per roll) is a little bit on the low side for Xtol?

I use for delta 100 ID-11 stock, 8.15 min at 68F. jk

Check page 4 of Ilford’s PDF technical sheet. Instructions for processing at temperatures other than 68 degrees may be found there.

I have tried to develop DELTA 100 in a couple of combos, but I found to get the nicest tones in Rodinal 1+50 with the film rated at ISO 100 or 125. The times are between 14 and 17 min.
Another way I use this film is rating it at ISO 64 and develop it for 10-12 min. in Rodinal 1+50. This gives me rather high contrast for experimental portraits, especially modern fashion work with harsh studio flash.

Greetings, Morten

Hi Terry.
Good you sorted out the problem yourself, but, whenever possible it is better to learn by the mistakes of others - it is also cheaper! Good luck. Stan L-B