Multiple Rolls = Extra Time In Developer (Perceptol)?

[grandallj]

Question about timing

I'm planning to try using Ilford Perceptol developer and have a couple of rolls of Delta 400 exposed at ASA 200. Ilford's data sheet says that 1 liter of Perceptol stock will develop 4 rolls of film, but it also discusses the notion of adding time for development of successive rolls if one is re-using the stock.

So -- if I were to develop 2 rolls concurrently in one tank, should I add any time to the recommendation that applies to 1 roll (10 minutes would be the time for 1 roll in fresh stock, according to the sheet)?

Thanks for advice --

Here's the data sheet link: http://www.ilfordphoto.com/Webfiles/2011427133131459.pdf

 

[Ronald M]

Successful B&W means knowing your materials and doing everything exactly the same every time. Time and temp are the variables most critical.

Trying to save a bit of developer is a fool`s errand.

 

[sevo]

That is no issue if you develop in stock: The amount of chemistry needed to submerge a 35mm reel in a narrow tank is about 250ml, so you need the required amount of chemistry just to fill the tank, to the required level, whatever amount of reels and films you use. Things would be different if you dilute Perceptol (where you would have to use twice or three times as much developer as reel volume), but even then, I would advise against using it below minimum volume. In general, it is unwise to use developers at or beyond the depletion threshold, at least unless you have the time (and intention) to run a full set of tests - developer may do very odd things when used that much beyond specifications.

 

[DKimg]

I'm not an expert when it comes to development and the use of perceptol but from my experience thus far using perceptol (mostly @1+3), I would advise not to reuse it more than once. I've at least experiment quite a bit, as perceptol is one of my main developers, and all I can say is that it definitely goes downhill with quality after reusing it the 2nd time.

But what Ronald M stated, it would be foolish to try and save developer by reusing it. I've learned my lesson with that already.

DK

 

[sevo]

Re-use was not even asked for. But I'd strongly advise against it - re-use is not even very wise when it comes to using ID-11/D-76 in a hand tank, even though that is comparatively patient, and has data tables for re-use - but for consistency you really need more than a measly 260ml/roll out of a 2l canister, the re-use/replenishment tables were calculated with tanks ten to a hundred times that size. And developer is cheap, much cheaper than film or most photo opportunities, there is no good reason to waste expensive film on exhausted developer...

 

[grandallj]

Successful B&W means knowing your materials and doing everything exactly the same every time. Time and temp are the variables most critical.

Trying to save a bit of developer is a fool`s errand.

I'm not trying to save developer, I'm trying to determine what time to apply when I'm developing more than one roll at the same time. The data sheet says the liter of stock has capacity for 4 rolls and I don't intend to use it for more than 4 rolls. The question is merely about what to do if I attempt to develop more than 1 roll at a time with fresh stock.

Now, re-use may become an issue insofar as I have 120 film to develop and would use 32oz of developer (whether stock or diluted) to develop 2 rolls in a double tank. So if I used the stock for one batch (2 rolls) and then saved it, I theoretically could use it again -- it would be within Ilford's stated capacity for that quantity of stock. I'd have to extend the development time by some amount and, as several have noted, there might be some degradation.

 

[Bill Clark]

Just a FYI, I develop one roll at a time. I use working solution once then discard.

However, my logic says, develop two rolls at a time, it takes twice as much developer to get two reels covered with developer.

Hence, I would develop with same amount of time as with one roll (reel).

One reason I develop one roll at a time as I have the tools(clips) to dry one roll at a time!

Hope this helps you.

 

[Roger Hicks]

Just a FYI, I develop one roll at a time. I use working solution once then discard.

However, my logic says, develop two rolls at a time, it takes twice as much developer to get two reels covered with developer.

Hence, I would develop with same amount of time as with one roll (reel).

One reason I develop one roll at a time as I have the tools(clips) to dry one roll at a time!

Hope this helps you.

Dear Bill,

Certainly. Any variation (and as you say, there is no reason why there should be any) would be far less than experimental error. Unless both of us are misunderstanding the question.

Cheers,

R.

 

[judsonzhao]

if your solutions can occupy the whole tank and merge the two rolls entirely, you should not add time. You need to add time once you reuse them, say, next time you develop two rolls using the solutions you left last time.

 

[grandallj]

I guess I could just use it 1+1. Develop my first batch of film, dump the used mix, and keep the unused half-liter of stock for the next batch of film. Now that I think about it more, I'm not seeing any reason to extend the development time beyond what's on the sheet assuming the stock/mixed solution hasn't been used before.

 

[sevo]

I'm not trying to save developer, I'm trying to determine what time to apply when I'm developing more than one roll at the same time. The data sheet says the liter of stock has capacity for 4 rolls and I don't intend to use it for more than 4 rolls. The question is merely about what to do if I attempt to develop more than 1 roll at a time with fresh stock.

You use (at least) 250ml per roll (can't avoid that in any case, as there are no tanks that make do with less), and develop to specification, that is all. There is no issue with 120 either, as the common tanks need about 420-460ml to cover a 120 reel (which will take one 220 or two 120) That is roughly the same film area per mm tank height as you have with 35mm - in doubt, fill up to 500 and you are set (but I'd expect a 10% margin by volume to be uncritical).

 

[Roger Hicks]

I guess I could just use it 1+1. Develop my first batch of film, dump the used mix, and keep the unused half-liter of stock for the next batch of film. Now that I think about it more, I'm not seeing any reason to extend the development time beyond what's on the sheet assuming the stock/mixed solution hasn't been used before.

That would do it.

Cheers,

R.

 

[Roger Hicks]

You use (at least) 250ml per roll (can't avoid that in any case, as there are no tanks that make do with less), and develop to specification, that is all. There is no issue with 120 either, as the common tanks need about 420-460ml to cover a 120 reel (which will take one 220 or two 120) That is roughly the same film area per mm tank height as you have with 35mm - in doubt, fill up to 500 and you are set (but I'd expect a 10% margin by volume to be uncritical).

At the risk of being a smart-arse, and answering a question the OP didn't ask, you are neglecting rotary development in e.g. a CPE-2. For normal tanks you are of course quite right.

I mention this only to make the further point that the vast majority of the developer that you pour into the tank is there to wet the film quickly and evenly. With very few exceptions, you don't need a great deal of developing agent to do the actual work, as evidenced by two-bath developers.

Cheers,

R

 

[grandallj]

Unless both of us are misunderstanding the question.

Cheers,

R.

Roger, I'm not sure I understand my own question anymore. A product of both over- and underthinking it after reading the data sheet. I will do the 1+1 approach, which will give me fresh developer in sufficient volume to process 4 rolls of 120 (which is the goal).

Thanks, all, for your patience and advice.

 

[sevo]

Roger, I'm not sure I understand my own question anymore. A product of both over- and underthinking it after reading the data sheet. I will do the 1+1 approach, which will give me fresh developer in sufficient volume to process 4 rolls of 120 (which is the goal).

You could also thread two 120 rolls into some spools. Jobo spools have a little red plastics tab to prevent overlap (which often has been lost over the course of time). A few other makers spools (e.g. old dedicated 120/127 metal spools) were too short, but every spool stated to hold 220 will hold 2x120 at least by length - but it may take considerable experience to prevent the inner roll from migrating outwards and to stop at the right point.

 

[Roger Hicks]

Roger, I'm not sure I understand my own question anymore. A product of both over- and underthinking it after reading the data sheet. I will do the 1+1 approach, which will give me fresh developer in sufficient volume to process 4 rolls of 120 (which is the goal).

Thanks, all, for your patience and advice.

Dear Gordon,

Always a risk!

I'm sure your 1+1 approach will work fine. The first 2 rolls will be more than printable. If you decide you need slight changes to exposure/development for the second two, they'll be even better.

Cheers,

R.

 

[aldobonnard]

Ilford recommends to add +10% time for the second batch