Confused about dev. time

[coops]

Just got some Ilford HP5 sheet and 120 film. I live in Florida and have a hard time keeping my darkroom below 76 degrees. Some people claim it is not advisable to dev. at this temp. Is this true? Should I use a large tray with ice and water to lower the water temp?
Secondly, the dev. times I have read using this film and 1:1 D76 range quite a bit, from about 6 mins to 9 mins. I doubt that much latitude is accurate, but perhaps it is.
Figured you guys would know. Thanks

[Ron Marshall]

This is the chart on Ilford's (Harman) website listing dev times for HP5 and various developers:

http://www.ilfordphoto.com/Webfiles/2006216122447.pdf

From the chart, for HP5 in D76, 1:1, at 68 degrees, time is 11 min; converting to 76 degrees gives a time of 7.25 min.

This time is for D76 1:1.

Kodak data for D76 list times for 75 degrees, so I am sure 76 is fine.

[coops]

Thanks for the response. I guess my next question, and forgive me if it,s a dumb one, is what conversion scale do you use to convert from 11 mins at 68 deg to the correct time at 76 degs? And does the conversion apply to all film?

Thanks again

[Ron Marshall]

Thanks for the response. I guess my next question, and forgive me if it,s a dumb one, is what conversion scale do you use to convert from 11 mins at 68 deg to the correct time at 76 degs? And does the conversion apply to all film?

Thanks again

Here is a time/temp chart good for all films (Click on time/temp chart in box on left side of page):

http://www.digitaltruth.com/devchart.html

[coops]

Nice. Cheers

[Gene McCluney]

Films from Ilford, Kodak and Fuji are modern "hardened" emulsion films and can be safely processed at elevated temperatures. You should test though, as a time/temperature chart is only a starting point for your own personal developing time derived from your exposure technique, agitation technique and personal taste.

[Brian Ellis]

The method used for development will have a major effect on your times and you haven't told us your method (or what method Ilford is assuming in its tables). One reason for the different times you mentioned that you've found may be because different tables were assuming different methods of development.

7' 25" at 75 degrees is surprisingly long to me unless perhaps it's assuming a development method involving periodic (as opposed to constant) agitation. I processed HP5+ 4x5 film in D76 1:1 at 75 degrees for many years. My tested normal development time at that temperature using BTZS tubes (constant agitation) was 5' 30" (FWIW, my other times were: N +1 = 8' 45"; N+2 = 16 minutes; N -1 = 4 minutes). As others have said, you should do your own testing, I mention my time just to point out the difference between my 5' 30" normal time and the 7' 25" derived from Ilford's table.

[Jim Noel]

Ilford's table is based on intermittent agitation.
The tables for converting from one temperature to another have been around for many years.I have used the one in Keepers of Light (1st edition) with all kinds of film and developers as well as varying development methods. It is accurate in every case I have tried.

[ignatiusjk]

Don't get t ocaught up with devo times try shooting a general scene no bright light or dim light and shoot 4-5 negs and try different devo times. HC110 dilution B worked well for me on Pant X 120@ 5-6 min. To many photogs like to get to technical with film and exposure.