Tri-X + D-76 (1+1) - 4 rolls in 1l tank

Hi all

Switching to a JOBO tank, got a 1540 (~1l - 975ml to be precise) which can handle 4 120 films at once.

With D-76 diluted 1+1, I read the instructions as I'm to extend developing time 10%, so 10 mins becomes 11, correct?

Also, should I use 500ml D-76 and 475ml water, or should i go 488ml + 488ml?

Rgds
Michael

500ml D76 + 500ml water. 975ml is the least amount of solution that can be used. Using 1l would do no harm. why do you need to extend development time by 10%?

Correct, 10 minutes plus 10% becomes 11 minutes.

If you're using a 1:1 mix, then you need exactly the same volume of dev to water.......if you need 1000ml, then that's 500ml of dev and 500ml of water.

Personally, i wouldn't aim for 488ml......much easier to measure 500ml and discard what's left over.

If your tank will take it, then use 1000ml.....it'll do no harm having more solution than needed.

Mike

Anon Ymous said:

500ml D76 + 500ml water. 975ml is the least amount of solution that can be used. Using 1l would do no harm. why do you need to extend development time by 10%?

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Thats from the Kodaks Technical Data for D-76: " You can develop one 135-3 roll (80 square inches) in 473 mL (16 ounces) or two rolls together in 946 mL (one quart) of diluted developer. If you process one 135-36 roll in a 237 mL (8-ounce) tank or two 135-36 rolls in a 473 mL (16-ounce) tank, increase the development time by 10 percent (see the following tables)."

Just making sure that I read the description correct.

Rgds
Michael

mpirie said:

Correct, 10 minutes plus 10% becomes 11 minutes.

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Mike, just to be sure, you're confirming that 4 films in D-76 1+1 should be developed for 11 minutes?

Rgds
Michael

Hi Michael,

I wouldn't give you times for Tri-X in D76.....i was just agreeing that adding 10% to 10 minutes adds up to 11 minutes.

If you want to check times, refer to the massive dev chart (www.digitaltruth.com) for a starting point.

Regards,
Mike

Worrying about the difference between 946ml and 1000 ml is 'micro management' in the extreme. Surely you have more valuable things todo with your time. Go with the 1000 ml and be done with it. No fuss, no bother, no stress.

Extending by a minute (or even two minutes) makes sense IF you tend to underexpose your shots by say, one third of a stop, or if you want to zip up the contrast by about that much, or if you print with a diffusion enlarger.

For any noticeable increase in contrast in the processed images, I would go two minutes more at least. However, I prefer my negatives just a tad under, as they scan better and also print more to my liking with a Leitz Focomat 1c (condenser) and Grade 3 or 3.5 Ilford filtration. So I process for the recommended times.

If in doubt about any of this, or if your images are particularly valuable, shoot a fresh roll as a test and process it. Ideally, expose a 36 exposure roll in the same conditions and cut it into two or even three sections. Process each at a different time. Keep notes.

As well, never ever re-use D76 mixed 1+1 a second time. Some say they do, but ignore that. It's false economy. I believe you are asking for trouble if you do, and trouble will surely find you.

This from one who in his time has processed many thousands of rolls in D76 1+1.

I guess that my english (2. language) isn't good enough, since my main question didn't come across clear enough.

I am asking with respect to the Kodak instruction for D-76:
"You can develop one 135-3 roll (80 square inches) in 473 mL (16 ounces) or two rolls together in 946 mL (one quart) of diluted developer. If you process one 135-36 roll in a 237 mL (8-ounce) tank or two 135-36 rolls in a 473 mL (16-ounce) tank, increase the development time by 10 percent (see the following tables)."

Given that the area of 120 films and 135's are equivalent, two rolls of 120 in 473 mL requires the 10% extension in development time. So does that mean, that when doubling this up, 4 films in 1 liter, just requires 10% extension, or more?

If anyone has experience with this, please let me know.

Thank you for all the other good advice, shared experiences and suggestions, but none of them answers my query.

Rgds
Michael

Michael, I've never used that 10% increase rule. I always regarded 100ml the minimum quantity of stock developer needed for a 135 36exp (or 120) film, regardless of dilution and used whatever development time the manufacturer provided, without extending it. IIRC, Ilford's suggestion for ID11 is 100ml minimum stock solution per film and they are more or less the same. For the record, I've developed film in 400ml of 1+3 solution and it came out fine, never had thin negatives.

Your problem arises because you are right up against the capacity limits of D-76 diluted 1+1.
Kodak's recommended developing times assume a certain amount of active development chemicals for each roll of film. Those recommendations include a safety factor.
If you are developing that many rolls, in that small a quantity of developer, you are at risk of exhausting or at least nearly exhausting the developer's chemical capacity.
The 10% increase in time that Kodak recommends will generally offset the capacity concerns, although you might still have problems if you have four rolls of dense (i.e. high key) negatives.
Yes, with your scenario, an increase from 10 minutes to 11 minutes should have the desired effect. The doubling from two rolls to four rolls should be appropriately offset by doubling the volume of working strength developer. And if possible, I would recommend 500 ml stock plus 475 ml water, because every little bit of chemical energy helps.
Or you could just develop in stock D76, in which case the capacity issues would go away.

Anon Ymous said:

Michael, I've never used that 10% increase rule. I always regarded 100ml the minimum quantity of stock developer needed for a 135 36exp (or 120) film, regardless of dilution and used whatever development time the manufacturer provided, without extending it. IIRC, Ilford's suggestion for ID11 is 100ml minimum stock solution per film and they are more or less the same. For the record, I've developed film in 400ml of 1+3 solution and it came out fine, never had thin negatives.

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The problem with this is that 100ml is so much less than Kodak's recommendation for a 250ml minimum.

Well, yes, it is 40% of the 250ml minimum Matt.

Think about it, if you wanted to use the 1+3 dilution (officialy supported by Ilford) you'd have to use a 1l tank for a single film. Does it sound right?

Anon Ymous said:

Well, yes, it is 40% of the 250ml minimum Matt.

Think about it, if you wanted to use the 1+3 dilution (officialy supported by Ilford) you'd have to use a 1l tank for a single film. Does it sound right?

Click to expand...

Yes
But of course D76/ID 11 weren't originally designed for small tanks. They were designed to be used in large tanks, with replenishment.
Ilford starts out with a 100 ml/roll recommendation for stock, and then recommends ever increasing development as you use it for more rolls.
Kodak approaches the issue in a slightly different way.
Both involve assumptions, including a determination of what the appropriate safety factor is.