HC-110 Dilutions Help

[LightWriter85]

Hello,

I am experimenting with different dilutions and development times with HC-110 and Ilford Delta 100. On this web-site (Covington Innovations (http://www.covingtoninnovations.com/hc110/)) it mentions that dilutions D and E require 25% and 50% more development time than dilution B because "With this developer, development time is roughly proportional to dilution," and indeed, dilutions D (1:39) and E (1:47) are 25% and 50% more diluted than B.
The development time for dilution B with HC-110 is 6 minutes, leaving me to believe that the times for D and E would be 7.5 mins and 9 minutes respectively. Since dilution H is 1:63, or 100% more diluted than B, my assumption is that dilution H would require approximately 12 minutes, or double that of B.
There is a thread on this forum where someone was complaining about low-contrast negatives with dilution H and Ilford delta 100 after developing for 10 minutes, perhaps this would not have happened if development would have been 12 minutes instead.
I suppose my questions are: 1) Is it safe to assume that the correct development time for dilution H, in this case, would be 12 minutes, 7.5 mins for D and 9 minutes for E?
2) On the Massive Dev Chart (http://www.digitaltruth.com/devchart.php?Film=Delta+100&Developer=HC-110&mdc=Search) for Ilford Delta 100 and HC-110 it only has one other dilution listed which is E, and it says it should be developed for 7.5 minutes, which would be the time for D if my assumptions are correct. Is this a mistake on their part?
3) Is it a better idea to use the same brand developer as the film used? In this case using Ilford developers for Ilford film?

I appreciate the help if available. Thank you.

[Ari]

You're on the right track; depending on how dense you like your negs, you could go from 50% to 100% more with dilution H.
I use dilution H for all my B&W films in a rotary processor, and the development time for me is always 9 minutes at 21˚C (T-Max and Acros).
Much depends on your exposure, printing (or scanning) method, and personal taste.
But keep in mind that things do not always work in such a direct linear fashion when working out development times.
Test your development, and you'll arrive at your ideal processing time; start with 50% more development, and go from there.

[jcoldslabs]

I, too, use dilution H for most all of my developing regardless of film type. I have found that agitation over these longer development times affects overall contrast more than time--to a point. My guess is Ari gets 9 minutes because of the constant agitation from rotary processing. I use a Jobo tank (non-rotary) with 4x5 reel and agitate using two tank inversions each minute for 12 minutes with most films. With this method I find that doubling the dilution B time is a good place to start.

Jonathan

[philbed]

I develop Ilford HP5 in Ilfotec HC dil E (similar to HC-110) for 9 min. As I use a condenser enlarger I follow the Ilford instructions for agitation for a gradient of 0,52, (Invert the tank four times during the first 10 seconds. Repeat these four inversions during the first 10 seconds of each subsequent minute of development). This is a very low agitation process. If you want more contrast, it's not necessary to change the development time but you have to adapt your agitation scheme for instance each 30 second rather than each minute.

[Doremus Scudder]

I used HC-110 a lot years ago and found the dilution/time ratio to be approximately correct. The key word being, "approximately."

I think, if 6 minutes is your tested "correct" time for dilution B, then 12 minutes is a good place to start with dilution H. You will be able to print the negatives and refine you developing from there depending on the contrast refinements you want to make to your negs.

Best,

Doremus

[Bruce Watson]

1) Is it safe to assume that the correct development time for dilution H, in this case, would be 12 minutes, 7.5 mins for D and 9 minutes for E?


It's not safe to assume anything, especially when you can test it and find out for sure. In this case, too much depends on your agitation method and how vigorously you apply that method. The only way to know what development time will give you the best results is to do the work yourself, with your own workflow.

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3) Is it a better idea to use the same brand developer as the film used? In this case using Ilford developers for Ilford film?

There's really no connection between brand of film and brand of chemicals.

Get yourself a copy of The Film Developing Cookbook (http://www.amazon.com/Film-Developing-Cookbook-Darkroom-Vol/dp/0240802772). It'll lay it all out for you.

[LightWriter85]

Thank you for the replies everyone, much obliged.

[Ari]

My guess is Ari gets 9 minutes because of the constant agitation from rotary processing. I use a Jobo tank (non-rotary) with 4x5 reel and agitate using two tank inversions each minute for 12 minutes with most films. With this method I find that doubling the dilution B time is a good place to start.

Jonathan

Absolutely true, Jonathan; I forgot to add that (constant) rotary development requires slightly less time than inversion.
Thus, if the norm is 6 minutes at dilution B, I add 50%, and not 100%, due to the rotary development.

[Michael Clark]

Is not there a minimum amont of the consecrate for a 8x10 area of film, think it is 3 or 4 ml?

Mike

[jcoldslabs]

I have read that 6ml of syrup concentrate is the minimum to fully develop 80 sq. in. of film surface area, but others have suggested you can get away with less. Only your own testing will tell you for sure. I have never gone below this amount. I tend to use a minimum of 10ml when I do 6 4x5 sheets in the Jobo tank.

Jonathan

[Michael Clark]

Could not remember the exact amount and where I read the information.

Mike