View Full Version : Tropical developers - any experience?

02-28-2009, 01:20 AM
I live in Bangkok, and it is more or less hot, hot, hot, all year long. I have just recently started developing film, and currently use straight D-76 for 5.5 minutes at between 80 and 90 degrees. It seems to work okay, but what do I know?

I wonder if I would be better off using a dedicated tropical developer like Kodak DK-15. Does anyone have any experience using tropical developers that they could share?

Alternatively, BradS (who I recently bought a camera from) mentioned in another thread that Kodak D-23 had wide temperature latitude, but at digitaltruth this formula is listed as low contrast. I guess I'm not educated enough to know whether I want that or not. Can anyone comment on the differences in negatives developed in D-76 and D-23?

I know I could control the temperature of the developer I am using, but with the process I use (very small amounts of chemicals in a light-tight tray) that is quite difficult in this environment, so I prefer to work with the normal temperature inside the house (which I try to keep at a comfortable 80 degrees).


02-28-2009, 02:40 AM
Originally films were not prehardened, the emulsion was soft, and developing at elevated temperatures would cause reticulation and the emulsion actually coming off the film base. Thus "tropical" developers were developed to help this condition. All modern films from the "Big 3" makers, Kodak, Ilford and Fuji are prehardened and can handle higher temperature processing. I think you can safely use almost any film developer as long as you reduce the developing time to compensate for the higher temperature. You might want to use a hardening fixer just to ensure emulsion integrity thru the wash step.

02-28-2009, 03:43 AM
Great! That makes things easy. I'm using cheap Shanghai 4x5 film that I buy direct from China, so its not one of the big three, but I understand they have some sort of connection to Kodak, so perhaps they are using that technology. In any case, I have not noticed any problems yet with emulsion integrity.

Thank you. I have not seen this information anywhere else, and expect that a lot of people who are currently cooling their solutions might profitably experiment with higher temperature development.

Best, Tim

David A. Goldfarb
02-28-2009, 06:51 AM
If you're not having problems with emulsion sliding off the base, reticulation, or emulsion frilling around the edges of the negative, then you probably don't need a tropical developer.

Mick Fagan
02-28-2009, 07:14 AM
I have used tropical developer(s) on and off a fair amount, dependent upon where I was living.

In Darwin which is about 12-13 degrees latitude from the equator, it isn't exactly cold, ever.

I developed film there in the very late sixties and again in the seventies. I used a tropical developer which was basically a developer with a single major difference over most normal developers, it has Sodium Sulphate added.

Sodium Sulphate has another use, which is medicinal. In it's medicinal form it is Glauber salt. I also use Sodium Sulphate as a hardener in the hardening bath, when manufacturing polymer plates. I buy it by the 10Kg packet, very cheap.

If you do some research on the net you should find some formulae regarding the addition of Sodium Sulphate as a hardener.

The film you are using could be alright without a hardener component, as David says.

I was nearly always using 29C or 30C in Darwin, which was the coolest temperature cold water got down to during the year. I needed a tropical developer as the emulsion used to lift off, or to be precise, slide off.


02-28-2009, 07:21 AM
Thanks David. I'm not having any of those problems. I thought the heat might affect the image (contrast, sharpness, etc), and I was just not experienced enough to tell the difference. Actually the negatives, when I expose them correctly, look fine to my untrained eye, so I guess I have no problem. Uncomplicates my life, as I was wondering where I would buy metol.

Cheers, Tim

02-28-2009, 07:30 AM
Thanks Mick. I was almost in Darwin earlier this month, on a trip to East Timor, but the trip got postponed. I read in the Darkroom Cookbook that Sodium Sulphate can be added to D-76 and you can then use the D-76 at normal development times for 68 degrees up to 85 degrees, so that would be an option, but I like the short development times, and it seems that modern films are less affected by the heat. That being said, the emulsion will probably slide off next time...

When you were using the modified developer, did it produce negatives that looked the same as those produced with the unmodified developer at cooler temperatures?

Mick Fagan
02-28-2009, 08:13 AM
Tim, give me a break, that was around 40 years ago. :D

To be honest I cannot remember, however the difference between any of my negatives from those times is that I generally get an image from every frame these days.

Back then I often had interesting frames, some very, very thin, others as dense as a coal mine.

As I got usable negatives and I was living in a tent about 30 miles out of Darwin, which then was bush, I was happy. The water was from the nearby stream and always obtained in broad daylight (crocodiles). Developer was May and Baker, cannot remember what exactly, but it was a white cardboard box with some red on it.

Film loading was done under a tarpaulin whilst sitting in a wooden sidecar, printing was done under filtered moonlight (trees) in the wooden sidecar. If I got a picture I liked I was happy, if I got a picture my friends liked, I was over the moon.

My film was tied to a tree branch with a tent rope and anchored to a rock or small log underneath to get tension, for drying. Sometimes I used to get mosquitoes stuck to the emulsion, they appeared to be attracted to the water, although they also liked me for my blood.

For what it's worth, the light from a half moon filtered through the leaves on a tree, is a reasonable safelight, if you're quick(ish)!

My enlarger was a miniature one that folded down into a little brown suitcase, I had Ilford 5x7" paper, either grade two or three, I cannot remember which, probably whatever the local chemist had in stock when I was flush.


Mick Fagan
02-28-2009, 08:21 AM
Forgot to mention that I also had a tin of Glauber's salt from the chemist, used to add of a cup (I think) when mixing up the developer for a tropical developer.

I got this tip from a local (Northern Territory) chemist, told me it would stop swelling of the emulsion if used on film. If I was crook I could take the Glauber's salt and it would enhance my innards outwards, as most people know. :D


02-28-2009, 08:41 AM
It sounds you had a grand time. Dodging crocodiles and developing by the light of the moon. I reckon you got the makings of a song there, if there was a girl as well...

02-28-2009, 08:07 PM
It sounds you had a grand time. Dodging crocodiles and developing by the light of the moon. I reckon you got the makings of a song there, if there was a girl as well...

yes- more stories please! what were you doing out there anyway?

Mick Fagan
03-01-2009, 05:51 AM
Nothing great, just fencing.

The property was reasonably close to a road and ran alongside the proposed Darwin to Alice railway line.

As the railway line was supposed to be coming within two years, the property owner was given a subsidy to build a fence to keep stock away from the trains.

I remember about 30 miles of fencing was required, we finished just before the wet. The fence was under water for a couple of weeks after a cyclone came through, but it was still standing after the water receded.

The railway line actually wasn't built for another 30 or so years, maybe the owners got another subsidy to rebuild or replace the original fence!


Ian David
03-01-2009, 06:20 AM
Temperature control may still be another option, although I appreciate what you say about the potential difficulty of keeping your tray and small liquid quantities at a constant reduced temperature while you are working with them.
This is what I often do here in Brisbane where the tap water in my place in summer is generally over 25 degrees C. I keep a big bottle of cold water, a cold bottle of mixed stop and a cold bottle of mixed fix in the fridge. I also keep a bottle of mixed stop and a bottle of mixed fix out of the fridge. Then when I am about to start processing, I make up developer with a mix of tap water and cold water, the stop with a mix from the cold bottle and the warm bottle, and the fix with a mix from the cold bottle and the warm bottle. With a thermometer and a bit of practice it is quick and easy to get all working chemicals to a starting point of 19 or 20 degrees C.