Ignoring density, what difference do temps make with B&W developers?

Ian Grant · Apr 2, 2018

You need to take out the term "Grain Clumping" that would imply the grain structure itself is being altered by the temperature shifts. What's actually happening is the temperature shifts cause artefacts in the gelatin super-coat (and also the anti curl layer with some 120 films) these surface artefacts (Kodak's term) are also called "Micro reticulation". When printed or scanned they cause more apparent graininess, wet mounting can overcome this and was first used around 1926.

Kodak have upgraded their hardening in recent years, to make their films more scanner friendly, but that doesn't mean we can be complacent films some films can have serious issues, this can be exacerbated by developer choice (Rodinal) and Acros is particularly prone to problems, the original Tmax400 was another, Foma films as well.

Ian

BMbikerider · Apr 2, 2018

What I don't think is what is described as 'room temperature' is made clear. If you are in an area where there is a significant difference of temperature to others then the times will inevitably change. For instance where I used to live almost 20 years ago in the South of England then room temp in the summer could be as high as 80 degrees F in the winter it could get as low as 50F, so working at what is described as room temp will vary wherever you reside. Unless of course you have the benefit of a darkroom that maintains a constant temp whatever the conditions are outside.

Where I am now in the North of England room temp at present is around 50F. Outside it is snowing - yes in April! We reluctantly get used to it. In the summer on a really good day it can rise up almost to as much as in the south so really you cannot depend upon it. This is the reason for B&W I have heated trays to keep the chems at around 70F. For colour the NOVA tanks are indispensable.

Without experimenting beforehand to work out the increased/decreased times, the figures given by the various film/chemical companies, will be grossly inaccurate. The effect of developing at too high a temp will be increased contrast, density and did I mention grain, big lumps of it!! ........At too low a temp decreased density and the image on film will bet are as flat as the proverbial flapjack! In many cases almost unprintable. (Words as well as the image).

RPC · Apr 2, 2018

When people say "room temperature" I think they mean where most people would have their temps set in a room with a controlled environment. Most, I think would want their rooms between 68-75F, or therabouts. Not 50 (don't you have heat?) , not 80, although these temps may work for some apps.

BMbikerider · Apr 2, 2018

As I said you get used to it. If I am sitting watching TV or reading a book, then yes I do crank up the heating but normally unless it is lower that 45F I don't feel the need. In the dark room I often work in just a T Shirt with no heating on. We are hardy folk up north!

John51 · Apr 2, 2018

I'm not that bothered about the meat thermometer being spot on accurate as long as it is consistent. I've got 2 of them and they agree with each other at various temps so I think I'm good there. Back in the day it could be a hassle finding 2 (cheap) thermometers that agreed with each other.

When processing film at somebody elses home, I think the Ilford rinse and dump method would be the most practical method for washing. Not truly archival but they're not going to be pics worth looking at in 2118 so nbd.

Doremus Scudder · Apr 3, 2018

Ian, I do know that "grain clumping" as such doesn't really happen... It just kind of slipped in...

BMbikerider said:
What I don't think is what is described as 'room temperature' is made clear. If you are in an area where there is a significant difference of temperature to others then the times will inevitably change. For instance where I used to live almost 20 years ago in the South of England then room temp in the summer could be as high as 80 degrees F in the winter it could get as low as 50F, so working at what is described as room temp will vary wherever you reside. Unless of course you have the benefit of a darkroom that maintains a constant temp whatever the conditions are outside.

Where I am now in the North of England room temp at present is around 50F. Outside it is snowing - yes in April! We reluctantly get used to it. In the summer on a really good day it can rise up almost to as much as in the south so really you cannot depend upon it. This is the reason for B&W I have heated trays to keep the chems at around 70F. For colour the NOVA tanks are indispensable.

Without experimenting beforehand to work out the increased/decreased times, the figures given by the various film/chemical companies, will be grossly inaccurate. The effect of developing at too high a temp will be increased contrast, density and did I mention grain, big lumps of it!! ........At too low a temp decreased density and the image on film will bet are as flat as the proverbial flapjack! In many cases almost unprintable. (Words as well as the image).

RPC said:
When people say "room temperature" I think they mean where most people would have their temps set in a room with a controlled environment. Most, I think would want their rooms between 68-75F, or thereabouts. Not 50 (don't you have heat?) , not 80, although these temps may work for some apps.

The point of this thread is that, with proper time compensation, film can be processed in a wide range of temperatures. "Ambient temperature" is not the same as a comfortable "room temperature." Film processing at 80°F just needs less time than at 68°F. The OP wanted a way to process at different temperatures. Adjusting for different temperatures by changing developing time is quite reliable and the Ilford time/temperature conversion chart linked to above is quite accurate.

Best,

Doremus

RPC · Apr 3, 2018

The chart only goes down to 64F. My understanding is that at some low temperatures such as 50F some developing agents do not perform well, so even changing time may not give results consistent with what is correct for a given developer at normal temperatures.

Ian Grant · Apr 3, 2018

RPC said:
The chart only goes down to 64F. My understanding is that at some low temperatures such as 50F some developing agents do not perform well, so even changing time may not give results consistent with what is correct for a given developer at normal temperatures.

Few developers will work well below 18ºC (64.4ºF), this is at its most critical when a developer contains two or more developing agents,

Ian

bvy · Apr 3, 2018

Ian Grant said:
Few developers will work well below 18ºC (64.4ºF), this is at its most critical when a developer contains two or more developing agents,

Ian

This is actually a strategy used to control fogging when developing very old film. I developed a 50 year old roll of Verichrome Pan in HC-110 A or B at 55F, and got some decent images.

K-G · Apr 3, 2018

Ian Grant said:
Few developers will work well below 18ºC (64.4ºF), this is at its most critical when a developer contains two or more developing agents,

Ian

I have read that Rodinal sometimes has been used at around 16 deg C ( 61 F ) in order to get finer grain. Does anyone have facts on this ?

Karl-Gustaf

John51 · Apr 3, 2018

K-G said:
I have read that Rodinal sometimes has been used at around 16 deg C ( 61 F ) in order to get finer grain. Does anyone have facts on this ?

Karl-Gustaf

That sounds interesting. My place is 16'C for a good part of the year.

Ian Grant · Apr 4, 2018

K-G said:
I have read that Rodinal sometimes has been used at around 16 deg C ( 61 F ) in order to get finer grain. Does anyone have facts on this ?

Karl-Gustaf

Using Rodinal at 16ºC is a technique once more common in Germany, it does not actually produce finer grain, However with older poorly hardened films it does slightly reduce the risk of "surface artefacts / micro reticulation" which appear as increased apparent graininess in prints and scans from poor temperature control because the gelatin swells less at lower temperatures.

When Agfa_Gevaert re-formulated Rodinal (RO-9) in 1963/4 after their merger they cut the level of p-Aminophenol and increased the pH by adding more Hydroxide, previously Rodinal had contained no free Hydroxide. This free Hydroxide increases emulsion softening and of course higher temperatures will exacerbate this as well., the films that need most care today are Fuji Acros and to a lesser extent Foma, but you won't have issues around the 20º - 22ºC range as long as you keep good temperature control across the entire process including washing.

Ian

Agulliver · Apr 4, 2018

I'm just going to add that I was 7 when I began processing film and making contact prints. It doesn't seem to have done me any harm, and nearly 40 years on I'm still developing and printing.

If you are in any way concerned about your granddaughter, I would say give her some eye protection (safety spectacles). It kind of depends on your setup. My mother once came home from work to discover me kneeling in the bottom of her bedroom closet making contact prints from glass plates and using her roasting dishes for the developer and fixer....and her vinegar for stop bath! Improvised dark room! So there were splashes on my hands but no chance of any chemicals getting in my eyes.

K-G · Apr 4, 2018

Ian Grant said:
Using Rodinal at 16ºC is a technique once more common in Germany, it does not actually produce finer grain, However with older poorly hardened films it does slightly reduce the risk of "surface artefacts / micro reticulation" which appear as increased apparent graininess in prints and scans from poor temperature control because the gelatin swells less at lower temperatures.

When Agfa_Gevaert re-formulated Rodinal (RO-9) in 1963/4 after their merger they cut the level of p-Aminophenol and increased the pH by adding more Hydroxide, previously Rodinal had contained no free Hydroxide. This free Hydroxide increases emulsion softening and of course higher temperatures will exacerbate this as well., the films that need most care today are Fuji Acros and to a lesser extent Foma, but you won't have issues around the 20º - 22ºC range as long as you keep good temperature control across the entire process including washing.

Ian

Thank you , Ian .

Karl-Gustaf

removed account4 · Apr 4, 2018

i believe it was mortenson who would put film in developer and stick it in the refrigerator for a day or 2 look up his 7-D approach

John51 · Apr 4, 2018

Thanks to all the good info. It's looking doable.

I can tolerate 16'C but haven't been in anybodies house that was cooler than that. Here in the north of England, our heatwaves can have room temps go to 25'C but they're rare enough to discount. It'll probably be in the range of 18'C to 22'C when it happens.

The film, FP4+, will be shot on my XA1 so no under exposure worries. D76 was the first choice but on the off chance that a friend or grandchild gets interested enough to take film up as a hobby, the mixing of chemicals might be a deal breaker so Rodinal is the current favourite. Too much visible grain on 35mm for me but the young 'uns tend to like that.

Ignoring density, what difference do temps make with B&W developers?

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