Thursday, March 3, 2011

HC-110 Resource Page by Michael A Covington

Here is a link to a superb technical resource page about Kodak HC-110 and its many uses, including monobaths and as a paper developer.

There is a lot of technical detail about this low toxicity developer that has long been favored by certain particular photographers, including Adams, and of course aficionados of the New55 Donald Qualls-inspired R3 Monobath, same as we have used with great success.

I am asking the most earnest users of Old Pol's T55 to please prepare to mix some of their own R3 and use it with Efke PL-25, as this will be an essential step toward the making of a T55 replacement later on in the New55 Program.

Once again, here is the link.

7 comments:

Greg Roberts said...

Bob, I sort of followed your suggestion to try mixing up some R3. I don't have any Efke 25, so I used Ilford HP5+. My initial results are on flickr: http://www.flickr.com/photos/gregrob/5525505014/

Bob Crowley said...

Greg
Nice work with the HP5+. Like the TMX and TMY, about 10 minutes are needed. Quall's ammonia monobath is very versatile and seems to work with a fair number of emulsions. The Rapid Fixer is ammonium thiosulfate. We'd like to repeat and confirm a two minute process to convince the funding sources that the mechanical part of the project is worth investing in, so if I can persuade you to try this with EFKE at 25C we will be closer to what the methyl cellulose filled version will be, we think! Maybe not. I'd like to get at least a half dozen well controlled experiments repeated in various geographic locations to show that users can get 1. the ingredients, and 2. get a result similar to what is obtained with the PL25 or the Pan-f as we have these as benchmarks. Meanwhile thanks for the interesting results!

Greg Roberts said...

Do you have a recommendation of where to locally source methyl cellulose?

I realize the 25C is nice temperature as it significantly speeds development, but wouldn't a 20C bath be easier for most people to attain? And if the works at 2 minutes at 20C then you likely get an even faster result at 25c?

Have you tried different efke emulsions? I do have some efke 100 sheets, but not loaded in any holders right now. Working with clips of 35mm film is certainly a quicker method for rapid evaluation of different formulations, and or different development times.

Bob Crowley said...

Greg

Please feel free to experiment: There are countless combinations of times and temperatures to explore. We just suggest this one time, temp and emulsion because after some experimentation we have been able to get what we think is a consistent and good result.

CMC or methyl cellulose can be bought on ebay and I think Amazon too. It is used for food, as a thickener. K-Y jelly is a source of CMC too. But if you get a bag of the CMC powder, you can create gallons of jelly! A litte bit goes a long way.

Where are you located? There may be a food supply outfit that carries it.

Bob Crowley said...

It is on Amazon!

Try this link

http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=methyl+cellulose&x=0&y=0

Greg Roberts said...

So I finally got around to trying the Efke 25 in R3 at 25C for 2 minutes. Turns out lovely, no problem with clearing as I was having with the HP5+.

http://www.flickr.com/photos/gregrob/5569933397/

Bob Crowley said...

AH! Thank you!!!! Look at that curve. Nice job. Thank you!!