Minimal chem for 8x10 dev

[Rscaboy]

Hello,

Could you confirm me what is the minimum of chem needed to develop an 8x10 sheet ?

I plan to use the D76 1:1 dilution 130ml stock + 130ml water is that enough for an 8x10 sheet ?

Also does it mean that I have to prepare the same quantity for each sheet that I want to develop or may I re-use the same chem for "X" sheet ?

Thanks for the answer

[Tin Can]

Maybe, but I don't use D76

I use Rodinol one shot 10 ml diluted 1/100 per sheet or 80 sq in

Read this https://imaging.kodakalaris.com/sites/uat/files/wysiwyg/pro/chemistry/j78.pdf

[Pere Casals]

Also does it mean that I have to prepare the same quantity for each sheet that I want to develop or may I re-use the same chem for "X" sheet ?

Se page 5 of the datasheet: https://imaging.kodakalaris.com/sites/uat/files/wysiwyg/pro/chemistry/j78.pdf , section "STORAGE LIFE AND CAPACIT"

It says that 1L of 1:1 dilution can do 2 sheets, so you need 250ml sotck + 250ml water to make a single sheet, then discard that solution.

Also it says "If you use Developer D-76 diluted 1:1, dilute it just before you use it, and discard it after processing one batch of film. Do not reuse or replenish this solution".

A recommendation: always read twice a datasheet, not all it says is true, but read it twice or three times !

[neil poulsen]

Interesting; this is useful information. I made my own tank for developing single sheets of 8x10 film with a minimum of developer. I think that I'm well above the 1 liter threshold; but I need to check to make sure.

[Jim Jones]

Long ago I used a Heathkit Color Canoe for developing single sheets of 8x10 film and paper. It took about 2 ounces of mixed developer to properly cover the film or paper. The developer was discarded after each sheet. The highly concentrated Kodak HC110 film developer is ideal for this use. It's data sheet https://imaging.kodakalaris.com/sites/prod/files/files/resources/j24.pdf implies that about 2 mL of the concentrate in about 3 oz of water would work well in the Color Canoe. The HC110 concentrate lasts for years in a partly full bottle.

[Tin Can]

HEATH-MITCHELL Color Canoe Stainless Steel Rocking Darkroom Film Developing Tray (https://www.ebay.ie/itm/321801385377)

Now that's a very good idea!

[Drew Wiley]

It takes very little developer to actually do the chemical work of developing. The greater problem is having enough solution volume to evenly cover the film and avoid surge marks, which in turn depends on your specific system of development. And it also depends on whether you're developing multiple sheets at a time, or just one at a time. In a highly efficient drum, even a single ounce of mixed developer can do it; other systems might require a full quart or liter. But there are a lot of variables. So you really need to divide this question into two aspects : 1)developer capacity before oxidation or exhaustion, and 2) the efficiency of your own equipment and technique.

[Luis-F-S]

I use HC-100 Dil B and use 300 ml per two sheets in an 11x14 unidrum.

[reddesert]

The datasheet that Pere posted the link to, says that the capacity of D-76 1:1 is per 1 liter: 2 8x10 sheets per liter in a tray, or 2 rolls of 135-36 or 120 in a small tank. Each roll has film area about equal to an 8x10.

If you've processed 35mm in a small tank, especially a steel tank, you know that you can only get about 16 oz (roughly 475 ml) of solution into a 2-reel small tank, which is half the rated capacity. What to do? Kodak helpfully notes at the bottom of page 5, "To extend the useful capacity of Developer D-76 diluted 1:1 - when processing two 36-exposure rolls in a 16-ounce tank - increase the recommended time by about 10 percent."

I developed 35mm that way, I have never developed 8x10 that way, but I would use Kodak's suggestion as a starting point. As others have said, you can't re-use the working solution of D-76 1:1.

[Drew Wiley]

All such specs are fudged for a significant margin of error. I could easily dev six sheets of 8x10 in a half qt of 1:1 D76 in a tray without fear of exhaustion or surge marks. I once routinely did it. But general instructions mandate greater conservatism both in terms of numbers of sheets and greater volume of solution. I never, ever re-use solutions of any kind, and never mix large volumes of developer long in advance, but always for sake of a narrow window of usage, segregated into full, tightly sealed amber glass bottles.

[Pere Casals]

All such specs are fudged for a significant margin of error. I could easily dev six sheets of 8x10 in a half qt of 1:1 D76 in a tray without fear of exhaustion or surge marks.

Drew, it always depends on how black the negatives are. Developer exhaustion depends on the silver amount it gets developed.

If your sheets are simply unexposed and only the usual fog level is developed then developer will last x10 to x40 times more sheets.

[Willie]

Are you tray processing? Closed tanks like Jobo or such? Other method?

Knowing the minimum needed is fine but no room for variables if you stick to that volume. Better to have some extra than right at the minimum, even with 'fudge factor' in mixing.

Mixing One Shot developer will give you more consistent and repeatable results than re-using developer that has lost a bit of its action. The cost of film and the time involved in photographing is more valuable to many of us than the cost of a few ounces of developer.

Good luck.

[Drew Wiley]

Why would anyone develop unexposed film, Pere? You might want to re-phrase that.

[Pere Casals]

Why would anyone develop unexposed film, Pere? You might want to re-phrase that.


All such specs are fudged for a significant margin of error. I could easily dev six sheets of 8x10 in a half qt of 1:1 D76 in a tray without fear of exhaustion or surge marks.

Drew, IMHO one can extend developer capacity beyond manufacturer's recommendations, but one has to be aware of the risks, in special if recommending other people to extend capacity.

Developer exhaustion depends on the amount of silver developed in a negative, if developing very dense negatives then a developer amount can develop less sheets than if the negatives are very thin, ideally if the sheet is not exposed then developer the exhaustion is very low, but if negative it's very, very dense then the actual capacity gets closer to the one recommended by manufacturer.

This has to be warned when recommending extended developer usage.