Diluted developers in BTZS tubes

[Garry Teeple]

I have been using BTZS tubes for processing 4x5 film. The problem came this summer when the incoming water and ambient temperature of my darkroom reached near 75 degrees. The recommended capacity for straight D76 is two ounces per sheet. According to Kodak publications it still requires two ounces of stock solution in a 1:1 dilution. The BTZS tube caps only hold two ounces. If Kodak is correct then it looks like I will need something other than D76 or HC110 to lengthen the development times. Has anyone used diluted developers in these tubes? The other choice is to ice everything down but one I really don't want to do.

[Jorge Gasteazoro]

Get an extra cap and have it ready with developer. Pour the old one and use the new developer to complete your time. Otherwise you are going to exhaust your developer.

[Oren Grad]

Garry, after seeing your question I double-checked Kodak's publication J-78 on D-76, and was surprised to see that that's indeed their recommendation. I say surprised, because I've always used only 1 ounce of stock D-76 per 20 square inches of sheet film surface, and my results have been fine. In practice, that means I develop 6 sheets of 4x5 in a Jobo 3006 drum using 12 ounces of D-76 1+1, and 5 sheets of 8x10 in a Jobo 3005 drum using 20 ounces of stock D-76. Specifically with respect to the BTZS tubes and 4x5, I've developed TMX in Phil Davis's darkroom, under his direction, using 2 ounces of D-76 1+1 (that is, only 1 ounce of stock) in the tubes. So I'd suggest you try it on a few test sheets and see whether it doesn't work for you after all. Just be sure the developer you're using is always fresh.

[Oren Grad]

Just saw Jorge's comment after posting mine. I should add for context that I'm developing film to contrasts appropriate for printing on traditional silver papers. I can't say from my own experience whether 1 ounce of D-76 stock per 20 square inches is enough juice to attain the kind of elevated negative contrast that Jorge needs for his Pt/Pd work.

[Brian Ellis]

I've been using D76 diluted 1-1 at 75 degrees in BTZS tubes for about 10 years, it works fine with HP5+ and TMax 100 and 400. Where did you see a recommendation of two ounces of D76 stock per tube? My recollection is that Phil Davis says two ounces of developer per tube, not two ounces of stock. But in any event, having developed at least 1,000 sheets using D76 1-1 in BTZS tubes at 75 degrees I can assure you that it will work fine. I develop anywhere from N - 1 to N + 2.

[Garry Teeple]

Thank everyone, looks like I need to do some testing. Kodaks recommendation must be to just sell more developer. I've always tried to stay within their recommendations just to be safe but times do change. The way Kodak is going I probably should be testing other developers also.

[Donald Qualls]

There seems to be some confusion. The recommendation I'm familiar with for D-76 is 100 ml of stock solution (that's a little over 3 ounces) for 80 square inches of film (135-36, 120 roll, 8x10 or four 4x5); that should allow use of 1+1 in the BTZS cap for a single 4x5. This is the same figure I've seen for XTOL as well. HC-110 requires 3 ml of syrup for this amount of film, regardless of the dilution; for 4x5, that would accomodate up to 1:79 (Dilution E) in the BTZS 2 ounce cap capacity.

[Garry Teeple]

I'm getting my information from a Kodak Master Darkroom Dataguide from the early '70's. The recommendation in it is sixteen 8x10 sheets per gallon. This is 20 square inches per ounce or 2 ounces for a 4x5 sheet. They also state that D-76 at 1:1 dilution is only half the capacity. I wonder if the amount of exposure on the film will have an effect, more testing it looks like.