Development Temperature vs. Grain - Data?

Hi all,

Very new to shooting film and getting into developing B&W at home.

I've shot a few rolls of various kinds (HP5, Kentmere 400, TriX, TMAX, Delta 400) and trying to see which I like the best.

Although I've noticed significantly different grain "character" from each film, all are consistently grainier than expected. To be more specific, I believe there is a higher contrast within the grain than I have seen in other people's samples, independent of clumping/density (TMAX and Delta are quite velvety, whereas I've noticed more grouping in the Kentmere/HP5).

I'm wondering if this is a result of the temperature used to develop. I am developing consistently at 24C (my bathroom's ambient temp, where all my material is stored), measured with a thermometer immediately before development.

I've heard a lot of heresay but haven't seen any scientific measurements of temperature's effects on grain pronouncement (same image, same film, same developer, different temperatures).

Does anyone have a link or reference to that kind of a resource? Very curious.

Thanks!

Using the proper times and temperatures for each film and developer combination, there is little effect of temperature on grain or sharpness.

PE

Thanks for the quick reply PE - known from experience?

Most of the films you mentioned were optimized for processing at 24 deg C (75 F.). You would need a microscope to measure grain differences between processing at 20 C. or 24 C. Your observations may be fulfilling your expectations.

p.s. PE bleeds yellow, he worked for a well known film and paper making company in Rochester, NY for many years. He now teaches workshops on emulsion making and coating.

With good consistent temperature control there is absolutely no difference in grain and sharpness with any film I've used whether working at 20ºC (68ºF) when in the UK or 27ºC (fraction over 80ºF) when I'm processing in Turkey. That's experience over a number of years and mirrors Kodak research.

If people are getting increased graininess and that's affeecting sharpness it's down to inconsistent temperatures during the process cycle which ideally should be kept very consistent at every stage.

Ian

You say they are all grainier than you expected. I find the grain of Delta 400 and TMax 400 to be very small. It depends on how much you are enlarging and also on the developer you are using. I use "fine grain" developers like Xtol, DD-X etc but it is a matter of personal preference. I recently developed a batch of 19 films at 24 C rather than my usual 20 C. That was because the weather was rather hot. Usually, my room temperature is around 16 C for much of the year so I have to warm solutions up rather than cool them down. Anyway, when printing and looking at the grain with a focus finder I could not detect a difference in grain.

pietb961 said:

Thanks for the quick reply PE - known from experience?

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Yes.

These should be obvious, but if you are not happy with the grain... don't forget to check the obvious.

I find significantly less grain in slower films such as TMAX 100 compared to faster films such as TMAX 400.

And I find significantly less grain in my pictures when I shoot on larger film sizes such as 120 or 4x5 compared against 35mm.

For the most grain, I will use half-frame 35mm camera and shoot a 400-speed film.

I am satisfied by the grain I get shooting 400 speed film in 120 and 4x5, but some others will prefer even less grain, for example what you get when you shoot a 100 speed film with 4x5.

darkroommike said:

p.s. PE bleeds yellow, he worked for a well known film and paper making company in Rochester, NY for many years. He now teaches workshops on emulsion making and coating.

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Good to know!

darkroommike said:

Most of the films you mentioned were optimized for processing at 24 deg C (75 F.). You would need a microscope to measure grain differences between processing at 20 C. or 24 C. Your observations may be fulfilling your expectations.

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Interesting - I didn't realize this since most charts/directions list 20C operating temp.

Ian Grant said:

With good consistent temperature control there is absolutely no difference in grain and sharpness with any film I've used whether working at 20ºC (68ºF) when in the UK or 27ºC (fraction over 80ºF) when I'm processing in Turkey. That's experience over a number of years and mirrors Kodak research.

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Excellent.

Svenedin said:

It depends on how much you are enlarging and also on the developer you are using.

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Good point - Ilfosol 3 is reputedly particularly "sharp" which may be what I'm noticing. I'll make a point of experimenting with some different developers in the future.

Bill Burk said:

And I find significantly less grain in my pictures when I shoot on larger film sizes such as 120 or 4x5 compared against 35mm.

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Didn't think to check the format of the images I was referring to - never hurts to check the obvious first...


Thanks everyone, really helpful!

pietb961 said:

I've heard a lot of heresay but haven't seen any scientific measurements of temperature's effects on grain pronouncement (same image, same film, same developer, different temperatures).

Does anyone have a link or reference to that kind of a resource? Very curious.

Thanks!

Click to expand...

Kodak lists an RMS Granularity for each of their films on the data sheet for that film. Tri-X is rated as 16 (fine grain) and Eastman 5222 as 14 (very fine grain). Unfortunately Ilford no longer does anything similar.

BTW forget about clumping it just does not occur. It is an old wives tale.

pietb961 said:

Good to know!



Interesting - I didn't realize this since most charts/directions list 20C operating temp.

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Developer time/temp charts list lower processing temperatures for a couple of reason, one of which in tradition, many early home darkrooms were in basements and other cooler parts of the house where a temperature of 18-20 C. (65-68F.) were more attainable, modern pre-hardened emulsions can be processed at quite a bit higher temperatures and often are in a commercial environment where time is money. Older emulsions would slide right off the substrate at higher processing temperatures or reticulate like crazy with sudden temperature changes. My own darkroom sits right at 72 degrees F. except in the depths of an Iowa winter, so that's my standard temperature.

Some time ago Kodak revised their temperature recommendation upward. Now you will find 24C (75F) listed. I have therefore changed my processing to 75F for Kodak films and have observed no problems.

Sometimes those electronic devices used to turn negatives into computer-viewable images can accentuate grain, especially if too much sharpening is applied. If that's the way you are working with these negs, the best way to make comparisons for things like grain and sharpness is to compare optically made prints.

Interesting this part of the control. I use a 10L bladder filled previously with filtered water allowed to go stale for all the processing steps. However my 10L of water was at 21.4 degrees yesterday, whereas the houses central heating was adamant the house was at 20 degrees, seems to me that if one doesn't carefully measure the temperature of the processing chemicals your development could be all over the place, 1.4 degrees difference can make a pretty substantial change to the required developing time going by the published charts (10% per degree in the Ilford guidance).

I find very small grain difference between 68 and 75 degrees. You need to carefully inspect to see it, but it is there.

The biggest difference is time in developer. Which relates back to dilution. More dilution requires more time & more grain. Pushing increases grain. Pulling reduces.

Take care not to be a slave to manufactures time which is set using their water and accurate thermometers and diffusion enlargers. If you use that time for a condenser enlarger, the neg will have too much contrast and grain.

Delta 400 in the early versions worked well in D76. The current is TERRIBLE. Use DD x or Xtol. Delta 100 is fine in D76.

Certain towns water supply makes big grain. My friend lives in one place and made wonderful prints on TM400 He used softened water one time and got golf ball grain. Even after I warned him.

Developers like Rodinal do not work well with 400 speed film

NJH said:

Interesting this part of the control. I use a 10L bladder filled previously with filtered water allowed to go stale for all the processing steps. However my 10L of water was at 21.4 degrees yesterday, whereas the houses central heating was adamant the house was at 20 degrees, seems to me that if one doesn't carefully measure the temperature of the processing chemicals your development could be all over the place, 1.4 degrees difference can make a pretty substantial change to the required developing time going by the published charts (10% per degree in the Ilford guidance).

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I reckon NJH is right. Getting consistent development outcomes by adjusting and maintaining a target temperature is very much the second best option for black and white chemistry. If development reaction kinetics are even vaguely first order over a moderate range of temperatures then a 10 degree Celcius change up or down means a doubling or halving of the reaction rate. A small change in temperature can mean a big change in results. Temperature is easy to measure but hard to control.
The best option is to work at an unchanging (and easy to measure) ambient temperature and adjust development time. This can be done with great precision, a second or two, with practice and a good darkroom timer.
I'm occasionally troubled by an inquisitive mind so I've done development tests between 34 Celcius and 13 Celcius to derive my own time versus temperature charts. As for graininess, whatever the temperature, grainy films stay grainy, fine grain films stay fine.

welcome to apug....

(the best advice i rec'd when starting my own darkroom was to choose one film and one developer and use it for a year to understand their capabilities...)

have fun

Hi - I'm new here too. I had a similar problem with too much grain when I started developing at home. Two things that affected it a lot were overdeveloping and scanner default sharpening. If you're scanning, dial the sharpening back to the minimum amount - you can add it later in Lightroom or any other image application. Unless your negs look thin, try dropping your development times or backing off on your agitation. Thick negs can result in grainy images. Sometimes I do it on purpose now and it "works" great.

Gerald C Koch said:

Some time ago Kodak revised their temperature recommendation upward. Now you will find 24C (75F) listed. I have therefore changed my processing to 75F for Kodak films and have observed no problems.

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Actually Kodak recommend much higher temperatures for roller transport development, up to 30C, but machine processing ensures accurate short process times and this is why times are on,y given for up to 24C for manual processing (dish or tank).

If your using a developer with a comparatively longer development time at 20C processing at say 27C which I do with Pyrocat HD still needs over 9 mins, the issue is when times drop below 5-6 mins.

Ian

The developer formula has the biggest influence on graininess. You have physical and chemical development. Among the chemical developers you have true fine grain formulae, so-called untrue fine grain developers that contain bigger amounts of agents like sodium sulphite that eats away on the silver salts during the process, and finally a number of diversely acting developers from old-time agents over caffenol to peenol, and whatnot.

P-phenylene-diamine is a true fine grain developing agent. Hydroquinone is a generally used developing agent and the base of wide range of MH, Metol-Hydroquinone variants. Metol is being replaced by Phenidone more and more. Potassium oxalate is an old-fashioned reducing agent which can help generating beautifully fine grained and low contrasted images.

The effect of a developer can be seen most distinctly with fast classic films. T-grain emulsions react less proportionally to the different developers due to their inherent silver protuberance structure. Fine-grain emulsions are the best precondition for fine-grain images for a given format. If you want high speed and fine grain, larger formats are the answer. But the cheapest ingredient to virtually grainless photographs is time. When you can expose for long(er) times you can use plates and films of little sensitivity. The way back to early photography is always open.

Europan said:

P-phenylene-diamine is a true fine grain developing agent.

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P-phenylenediamine is a very weak and slow acting developing agent that when used alone produces low contrast images. Its use in fine grain developers is primarily for its action as a silver halide solvent. With some films it can cause dichroic fog.