Development time adjustment (ID11=D76)

[valdas]

I've been developing BW film for ages and this basic question never came to my mind because usually I don't develop many films at a time...
So here we go - I assume that developing time in the datasheets provided by film/chemistry manufacturer usually applies to single film. Then if developing in stock solution, there is a recommendation to increase development time by x% for each next film (e.g. 1liter stock = 10 films, first= standard dev. time then plus 10% for each next film). What about the situation if I develop 5-6 films at a time as one batch, how much should I adjust the developing time (if at all) - is it the same as if I was developing the 5th or 6th film? Intuitively this does not sound right to me... Another situation - if it is not stock, but 1:1 (which I prefer) and I develop several films at a time, do I need to adjust development time? What is your experience?
Thanks

 

[sevo]

YMMV. Actual depletion may not always be linear, and besides depletion through the active chemicals oxidizing while reducing the exposed silver, there also are depleting effects due to water brought in or carried out during the development stage, air contact or by chemical pollution with salts, surfactants and sensitizers from the film.

The right development time for n films simultaneously will usually be between that for the first film (given one shot developer with enough liquid per film) and half way between that and the time for the n-th (for a multi-shot developer depleted in that one run), but there will be exceptions.

 

[Ronald M]

I personally would not use a non relenished stock process because I demand perfect control. The few minutes or few pennies you save at time of development may mean a lot of wasted paper and time when you go to print them.

I use 1:1 as a one shot 90% if the time, sometimes stock as one shot, rarely 1:3 ( 16 oz per roll) for utmost sharpness.

If you want to use stock, mix some D76R and replenish as you go. This reguires a densitometer and test strips to do properly, but you can just use the recommended average replenishment. Either way, as bromide builds up in the developer, you get a decrease in film speed. Supposedly really nice negs result if the process is well controled but well controlled is difficult in a low thruput home process.

D76 is cheap at $5 or ten dollars a gallon, $2 if you scratch mix as I do a liter at a time, so consider the life of it 6 months, how much money will you save?

 

[valdas]

I personally would not use a non relenished stock process because I demand perfect control. The few minutes or few pennies you save at time of development may mean a lot of wasted paper and time when you go to print them.

I use 1:1 as a one shot 90% if the time, sometimes stock as one shot, rarely 1:3 ( 16 oz per roll) for utmost sharpness.

If you want to use stock, mix some D76R and replenish as you go. This reguires a densitometer and test strips to do properly, but you can just use the recommended average replenishment. Either way, as bromide builds up in the developer, you get a decrease in film speed. Supposedly really nice negs result if the process is well controled but well controlled is difficult in a low thruput home process.

D76 is cheap at $5 or ten dollars a gallon, $2 if you scratch mix as I do a liter at a time, so consider the life of it 6 months, how much money will you save?

It's about time, not money. I prefer 1:1 one shot, but have 5 same brand, same speed films exposed the same way, so it would be very convienient to develope all of them as a batch in this 1:1 solution, but surely I don't want to compromise the quality, therefore I ask this question...

 

[sevo]

It's about time, not money. I prefer 1:1 one shot, but have 5 same brand, same speed films exposed the same way, so it would be very convienient to develope all of them as a batch in this 1:1 solution, but surely I don't want to compromise the quality, therefore I ask this question...

For one-shot, the development time varies with area of film/unit of developer - but usually you need not bother to calculate that unless you operate large lab gear. With daylight tanks/spirals, the amount of extra developer needed per spiral is pretty close to that needed for the one-film charge, and will be big enough to keep you away from depletion, so that the time is constant regardless how many spirals you stack up.

 

[valdas]

For one-shot, the development time varies with area of film/unit of developer - but usually you need not bother to calculate that unless you operate large lab gear. With daylight tanks/spirals, the amount of extra developer needed per spiral is pretty close to that needed for the one-film charge, and will be big enough to keep you away from depletion, so that the time is constant regardless how many spirals you stack up.

thanks a lot... but still not sure and need clarification. so, 1l stock is enough for 10 films. Now, I have tank with 1l capacity where I can stack 5 spirals of 35m film. I prepare 0.5+0.5 so that I use full capacity of my tank - can I load 5 films here without developing time adjustment? Or from other end - what's the minimum quatity of 1:1 solution that will be sufficient for 1 film without developing time adjustment, because oh, forgot to mention - I will use rotary Jobo tank where the minimal quantity of liquid for my smallest tank is 0.24 l and I can load two 120 films here (but I'm sure developer would be depleted quite soon if I do this). and then i surely need to adjust because of permanent rotation... uffff....

 

[sevo]

thanks a lot... but still not sure and need clarification. so, 1l stock is enough for 10 films. Now, I have tank with 1l capacity where I can stack 5 spirals of 35m film. I prepare 0.5+0.5 so that I use full capacity of my tank - can I load 5 films here without developing time adjustment?

If you have a time for one-shot development in 1+1 dilution (and a minimum permitted developer amount of less than 200ml), you can do two one shot runs from that amount. If all you have are times for stock, you could do the first run in stock, at base time (or slightly longer). The second run would then be in half depleted stock, with adjusted time.

In any case, all factory recommended times (as well as guesses we make here) are start values - we don't know the chemistry of your tap water or flaws of your thermometer, stop watch and peculiarities of your agitation method. Pro labs would start from there with test strips, and shorten or extend development until the densitometry of the test strips is dead on spot.

Sevo

 

[katgut@earthlink.net]

The original post header says D-76=ID11, but I'm not sure that's quite true. Just look at Ilford's own spec sheets--they give different times for many films.

 

[Al Kaplan]

I have a variety of sizes of SS tanks so I use whichever sizes I need for the amount of rolls and the tanks are full. It's about 8 oz. of soup for each roll. You're not supposed to develop a second batch through used D-76 1:1 but it works fine if it's developer you just used, not stored after use. Add a minute to your times.

Worrying about the differences between D-76 and ID-11 is right up there with worrying if a Leica medium yellow filter is better than a Vivitar.

For instance: you have two Leica cameras of the same model. The shutter speeds and meters are "within tolerance" which DOES NOT mean accurate. The two cameras could easily be a stop apart and still be "within tolerance". Your darkroom thermometer might be a degree or more off, the ph of the water might be different than the stuff that Ilford used for deriving their data. And on and on...

You might like denser or more contrasty negatives than I like....you have to do your own tests, and you have to learn how to make great prints from negatives that aren't always the best. Have fun!

 

[venchka]

Back in the Dark Ages, Kodak stated "8 oz. D-76 developer per 8x10 film equivalent." They have since changed the wording, but you get the idea. Do many folks use a different amount of D-76 with good results? Sure. But they got there with individual testing.

Personally, I prefer Xtol 1:3. A more active and robust developer than D-76. 100ml per 8x10 equivalent works fine.

YMMV.

 

[Al Kaplan]

Just remember that it takes about 250 ml/8 oz. of developer to fully immerse a 35mm SS reel.

 

[valdas]

but you can do with less in rotary tank. 240ml is enough for rotation in Jobo Unitank 1500 unit and you can load 2x 35mm films

 

[Roger Hicks]

Exhaustion is seldom the problem. Rather, it's bromide build-up.

If you have a reasonable amount of developer per film (let's say at least 100 ml, which you can probably get away with in a rotary tank), extending development time should not be necessary.

Besides, if it is, you'll soon know. Develop for the time that gives you an adequare print on Grade 2-3, or a tolerable scan. If contrast is too low at the single-film time, increase it.

Finally, don't get obsessive about quality variations. They are usually well within the range that can be controlled with harder or softer paper. Remember: there is no variation in quality that is too small to be noticed by some people, including variations that do not exist.

To quote a friend from Ilford, back in the days when they coated for other people, on a comparative test: "We were delighted to be narrowly beaten by our own identical product."

Cheers,

R.