D76 equivalent to HC110-B

Discussion in 'Black and White' started by ben_hutcherson, Feb 3, 2018.

  1. I recently acquired some glass plates, and the developing instructions with them are a bit scarce. They advise 5 min in HC-110 dil. B "or equivalent." I used straight D76 for 5 1/2 minutes.

    Looking at some of my favorite emulsions, the times seems comparable. I think I exposed the plate fairly well(metered, but 4s at f/22 under an overcast sky and EI 2), but it's still quite thin.

    So, with that in mind, I'm wondering if anyone can advise any guidelines on how to get things at least in the ballpark for developing these.

    Alternatively, I'm guessing that I should just buckle down and buy some HC-110. I'd have picked some up if the local camera store carried it...

    Also, for reference, I also have Rodinal, TMAX, and Dektol on hand. I'd appreciate any advice if any of those would be more suitable.
  2. Are you saying that you DID develop the plate and they came out thin? What developer did you use? temp? I've done a lot of testing of films and developers over the decades, when I have a partial failure and when I redo the test I, A: increase the exposure by 1 stop, 2 stops or 3 stops. B: increase the developing time by 50%, 75% or 100%. C: increase the temp of the developer from 68* to 72*, or 75* and sometimes I do a little bit of all three till I get to a useable negative.
  3. I did 5 1/2 minutes with straight D76 and 20ยชC.

    I used 4s(manually timed) at f/22 for these ASA 2 plates. The image is thin enough that it's barely visible.

    I'm hesitant to up the temperature too much as the maker says that the emulsion is fragile when wet. I did it in an SP-455 tank held sideways and agitated by gentle sloshing.

    In any case, the plates are safelight safe, so perhaps next time I'll watch them develop.
  4. This is one of two problems. I have a feeling they were underexposed. ASA 2 at f/22 on a cloudy day? I'd say probably 10 seconds and maybe 20. You might also go to 10 minutes development and I would not be surprised if 15 was better.

    Rick H.
  5. I am assuming that you don't have a ton of these plates to do extensive testing, so you may have to do a Hail Mary. To me, the key words are "barely visible" which indicates gross underexposure. You may have to increase exposure 3-4 stops and increase development by at least 50%. Other things to consider are: Are the plates out of date? if they are, how out of date are they? Are they Panchromatic plates or are they designed for spectral photography, sensitive to a very narrow color of light?
  6. Thanks guys.

    These are fresh plates and have roughly the same spectral response as paper(if I understand the maker correctly).

    I'll try increasing the exposure time(I did meter it).

    Also, they are safelight safe, so for next time I probably should heed that advice and tray develop them by inspection.
  7. If it's sensitivity is similar to paper you might try an enlarging meter if you have one.
  8. Or do some test shots on paper. I used to have fun making paper negatives with an 8X10 Deardorff because I couldn't afford film.
  9. Alright, I tried 2s at f/16 on a sunny day(metered for the shadows) then developed for 5 1/2 minutes in Rodinal 1:19. We're getting there at least, but still not to a good workable density.

    I have HC110 due to be delivered today, so my next attempt will be overexposed by one stop relative to this and then tray developed by inspection in HC110 B.

  10. That looks like plenty of development, maybe too much, but not enough exposure, to me.
  11. +1. Definitely underexposed with hot highlights. Add a stop or two more exposure and cut development in half or double the dilution at the same development time.
  12. Okay, plate #3 this afternoon.

    I did 8 second at f/16(slightly overcast) then 5 minutes in HC-110 B(I finally have some). It's still a BIT thin for my taste, but I'm going to try contact printing tomorrow. I didn't appreciate just how delicate this emulsion is and did lift it a bit through washing a bit too vigorously, but it's fine. I actually picked up a nifty 4x5 contact printer at a flea market yesterday.

    BTW, I thought I'd blown this one since my plate holder came apart when I was pulling it out of the camera. Fortunately, it stayed light tight, and I've already glued the holder back together. It separated at one of the dovetails on the end, so I figured that was a perfect application for the modern miracle known as polyurethane glue-AKA gorilla glue.
  13. Vincent Peri

    Vincent Peri Metairie, LA

    Hmm... go Great Apes, go
    Great Apes...

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