Is 80f too warm to develop?

subtlelikeatrex · Jul 19, 2025

Hi folks. I’ve been developing my B&W film at home again for the past couple months and, for the most part, am enjoying the process along with the cost savings.

The issue:
My “cold” tap water comes out of the faucet at 79.5°f here in Hawaii. I have been using a plastic storage tub to create an ice-water bath to bring everything down to ~68°, which works but it’s a bit of a pain to do so often.

The problem is exacerbated by the fact that my tap water is also very hard. (When I tried to do my final wash with it, the negatives came out very spotty even with the use of Photo-Flo.)
I now use distilled water to mix with my developer and to do the final wash and photo-flo.

So that means I have;
A one-gallon bottle of tap water for stop bath and for the first part of the final wash (fill & dump immediately 3 or 4 times),
A one-gallon bottle of distilled water to dilute my Xtol and for the final wash and wetting agent,
A 1-liter bottle for my developer,
A 900ml bottle for my fixer, all sitting in the water bath. Juggling the timing of getting everything to the right temp is taxing. While I don’t get too precise about everything being at the exact same temperature, I do try to keep the water jugs and developer within a degree of each other. The fixer I will allow to be within a few degrees of the rest but since I’m going through all the effort I usually get to about the same temperature anyway.

All that being said, is 80° an acceptable temperature for everything to be at? I know there are time/temp conversion charts but some don’t show 80°. When I googled it, the AI result says it’s not recommended but these new AI search results are often wrong.

So what is your experience? Do any of you live in the tropics and deal with 80° water?

I’m thinking of getting an aquarium chiller so I can let the machine do the work for me so I don’t have to keep screwing around with ice cubes… and hot water when I let certain things get too cold.

Thanks,
José

pbromaghin · Jul 19, 2025

All of the Ilford developer data sheets recommend no higher than 79f. The Morgan & Morgan Darkroom Book has a recipe for a special tropical developer Kodak D-15. They recommend it for temps as high as 95f

mshchem · Jul 19, 2025

No worries. Way back when a hardening bath was required to prevent damage to the gelatin (emulsion) of the film. Consider the temperatures used for color processing.

Also you can develop at 75°F and wash in warmer temperatures.

Avoid developing times so short (under 4 minutes) that you get frazzled.

Using diluted developers, like D-76 1+1, XTOL 1+1, helps to stretch out the time.

reddesert · Jul 19, 2025

I live in the Southwest US. It is hot in the summer, both the room and my tap water are warm, and my tap water is very hard. It's fine to drink, but it's rather hard for film developer.

I mix developer stock solution with room temperature distilled water. This is say 82 F. I usually use a 1:1 working solution, and while diluting I put some tap water ice cubes or tap water that has chilled in the refrigerator in it as part of the dilution. This makes it easy to bring down to about 75 F, which is well within the range of developing charts and so on. 80 F would probably be okay, but it is not hard to hit 75 F. I don't care about mixing some tap water into the developer working solution: it's usually less than half, and even a half-distilled, half-very-hard solution is only mildly hard. If I really wanted to fuss over this, I could chill a gallon of distilled water in the fridge, and use that plus room temp water to make a full distilled solution.

I use tap water for the stop, fix, wash-aid, and water wash. I figure 80-85 F is fine for those. I haven't had any issues due to the hardness. I also do not worry about modest temperature changes like moving film from a 75 F to an 85 F solution, especially not with a modern emulsion.

I use room temp distilled water for the last stage, the Photo-Flo. I don't squeegee, just hang it up to dry.

ags2mikon · Jul 19, 2025

I have used 80 degrees with T-Max films with out problems. Not Foma though. You will have to dilute your developer, otherwise the times get too short.

retina_restoration · Jul 19, 2025

I keep cold distilled water in the fridge and use it to mix water to a reasonable temperature immediately before starting processing film.

albireo · Jul 19, 2025

retina_restoration said:
I keep cold distilled water in the fridge and use it to mix water to a reasonable temperature immediately before starting processing film.

This. I do the same.

abruzzi · Jul 19, 2025

Right now cold comes out of my tap at about 32C (90F). So the very first thing I do is mix up my developer and stick in in the freezer. Then I get the film holders, and dev tank, go in my darkroom and load them. Then I fill it with water as a pre wash (the 32C water). My other chemicals are room temp which in the summer if 25C (77F) but I since those run to completion, and modern film seems really hard to reticulate, I just use it as-is. Usually by the time all the prep is done the dev is close to 20C. I only use distilled water for the the last photo-flo bath.

mwdake · Jul 19, 2025

Where I lived until last year the tap water would get to 84F.
As the interior of my house was usually around 75. If the tap water was above 80F I would just fill a jug of water and leave it on the counter for a few hours before mixing up my developer.
Once it was below about 80F I’d be good to go and adjust the development time according to the Ilford chart.
What is the temperature in your house, could you try the same?
Now that I’ve moved I have the opposite problem.

koraks · Jul 20, 2025

ags2mikon said:
I have used 80 degrees with T-Max films with out problems. Not Foma though. You will have to dilute your developer, otherwise the times get too short.

I don't expect 80F/27C will be a problem for Foma films either. You're right about development times.

The main issue with very high or very low temperatures IMO is that you run into regions of non-linearity. E.g. take this often-cited figure from p.449 of Mees based on work by Ferguson and Howard in 1905:

What this shows is that the compensation for variations in temperature are non-linear to begin with (note the non-linear scale of the vertical axis), but that for some developing agents, the compensation factor even expressed as a log-function won't be constant across a wide temperature range. To make matters worse, the temperature compensation isn't the same for all materials (films, papers) either.

Within a reasonable temperature range and accepting a certain fudge-factor, tables like the Ilford compensation table/chart can be used. It won't be exact science, since as indicated above, 'it depends'. However, the question really is what level of exactness you're after. Personally, I wouldn't hesitate to develop my B&W film at 27C if that's the water temperature I happen to get out of the tap. I would do so in the awareness that my negatives would be a little 'off' - but that scanning as well as printing on variable contrast paper would allow me sufficient flexibility to deal with that slight problem. On the other hand, I'd hesitate to develop in temperatures significantly below the standard 20-22C: it's all too easy to heat half a cup of water so a jar of 20C can be mixed, and there's a limit to my patience waiting for my film to develop...All of which goes to show that IMO this is really a practical consideration for the most part, and not a very theoretical/fundamental one.

Ian Grant · Jul 20, 2025

When I lived in Turkey the Spring to Autumn water temperature was a constant 27°C (that's 80.6°F), so I always processed at that temperature. I never had an issue and in fact it was easy to keep to within +/- 0.2°C of that 27° because that was roughly the ambient room temperature. I used a digital thermometer.

Ian

Paul Howell · Jul 20, 2025

Ive processed 70s and 80 vintage TriX and Plus X, along with the ILford versions in the tropics at 80s degrees, in those days I used standard fix as I could get it in quart sizes so there was a hardener. There was guy who posted years ago that he developed all his film at 90s degrees, the images he posted were ok. I would try a roll at 80 degrees and see how you like the results.

beemermark · Jul 20, 2025

I use a 1:1 developer/water ratio. With water over 80f I use developer higher than 75. I get water from my fridge to add to the developer until I get 68f. Not that hard l

Maris · Jul 20, 2025

Modern black and white films develop nicely at elevated temperatures. Three precautions that work to promote even development at short developing times are:

1. Pre-soak the film in water at the temperature of the processing solutions; developer, stop, and fix all the same.
2. Get the film in and out of the developer smoothly and quickly. Hesitation risks the formation of a "tide mark".
3. Prompt agitation as thorough and random as you can do. Practice makes perfect.

When I look at my development chart for Fomapan in replenished Xtol I see 80F for 5min 40 sec, 90F for 3min 25sec. Both work fine.

DREW WILEY · Jul 20, 2025

Why can't you simply improvise a water jacket with an ice pack in it? It's a far better approach than gambling with higher temps.

But there are various related questions. What format of film is being contemplated? How do you process it? How much direct handling will it get? What specific developer? I've seen even roll films edge frill at just 75F. I've seen grain structure changes.

MattKing · Jul 20, 2025

FWIW, I would personally be more concerned about my working in warm (and often humid) 80F temperatures, than with taking appropriate steps to use 80F temperature chemicals.
What can I say, I'm used to a temperate climate!

Sirius Glass · Jul 20, 2025

The problem with developing black & white film at 80 degrees F is that the development time for most developer is less or much less that 5 minute. As the development time drops from 5 minutes and purposeful or accident variation that occurs becomes more pronounced and does not get averaged out with the normal longer developments.

koraks · Jul 21, 2025

Sirius Glass said:
As the development time drops from 5 minutes and purposeful or accident variation that occurs becomes more pronounced and does not get averaged out with the normal longer developments.

But in practice, development times like 3-4 minutes are perfectly feasible as @Maris also confirms. Plenty of people do C41 at home - that's 3m15s development time.

Tel · Jul 21, 2025

My tap water has been running around 78F lately (hot spell underway). When that happens I use the ice cube method: I have a large graduated pitcher and I throw some ice into it and stir vigorously until it gets down to 20C. Then I have enough for a pre-wetting bath and mixing developer and initial water-only stop bath. After that, I fix (room temp) and rinse in tap water and finish with room-temp distilled water. It slows me down a bit at the beginning, but the payoff is that it takes less effort to get up to 102F when I’m doing C-41!

subtlelikeatrex · Jul 24, 2025

After all the helpful replies I realized it's a bit less work to get the water bath to bring the chems to 75 and adjust to that temp.
Thanks all!

subtlelikeatrex · Jul 24, 2025

DREW WILEY said:
Why can't you simply improvise a water jacket with an ice pack in it? It's a far better approach than gambling with higher temps.

But there are various related questions. What format of film is being contemplated? How do you process it? How much direct handling will it get? What specific developer? I've seen even roll films edge frill at just 75F. I've seen grain structure changes.

I'm going to have to google that. I don't know what a water jacket is.

I develop 35mm and 120mm b&w film in plastic spiral tanks using xtol and ilford rapid fix with water as a stop bath.
I also develop 4x5 b&w sheet film in a Stearman Press tank. Same chems.

Sirius Glass · Jul 24, 2025

koraks said:
But in practice, development times like 3-4 minutes are perfectly feasible as @Maris also confirms. Plenty of people do C41 at home - that's 3m15s development time.

That was why I specified black & white development.

MattKing · Jul 24, 2025

Sirius Glass said:
That was why I specified black & white development.

Just as with colour film, you can use short development times with black and white.
In the past, most commercial labs did.
The issue is that short development times require a fairly high level of care in order to ensure consistency as well as evenness of development.
Longer development times are more forgiving of small errors.

koraks · Jul 25, 2025

Sirius Glass said:
That was why I specified black & white development.

If anything, B&W allows more leeway in process variations.

joho · Jul 25, 2025

Temperature of 68f [20c] was set as the threshold for B/W as that is where they start to work.
above that it is a matter of how one stander the process.

Is 80f too warm to develop?

subtlelikeatrex

pbromaghin

mshchem

reddesert

ags2mikon

retina_restoration

albireo

abruzzi

mwdake

koraks

Moderator

Ian Grant

Paul Howell

beemermark

Maris

DREW WILEY

MattKing

Moderator

Sirius Glass

koraks

Moderator

Tel

subtlelikeatrex

subtlelikeatrex

Sirius Glass

MattKing

Moderator

koraks

Moderator

joho

Is 80f too warm to develop?

Moderator

Moderator

Moderator

Moderator

Moderator

Privacy & Transparency

Privacy & Transparency