Tropical Developers

[Krzys]

From The Manual of Photography 8th edition

For processing at high temperatures up 35C

DK-15

Stock
750ml Water
5.7g Metol
90g Sodium sulphite, anhydrous
13.5g Borax, crystals
2.9g Sodium hydroxide
1.9g Potassium bromide
46.5g Sodium sulphate, anh stockydrous
Water to make 1000ml

Use without dilution. Times: 8min at 21C, 3.7min at 30C, 2.5min at 32C

D76
For temperatures 29-32 add 100g of sodium sulphate per litre of d76

The D76 solution interests me quite a lot, though since I don't have any fresh film to spare on new experiments can anyone share their experiences with developers catered for high temperature. Contrast is my main concern.

 

[Anon Ymous]

Do you think you really need a tropical developer? They were meant to be used with less hardened films than we use today.

 

[Krzys]

No I don't need one. It just sounds appealing with the water coming out of the tap over 30 degrees.

 

[Anon Ymous]

We live in places with probably similar temperatures, so my workflow is probably fine for you. First of all, developing at 24C is easy; development times are shortish, so maintaining temperature is easy. A water bath and a presoak is all that is needed. The later can be probably omitted if you don't wish to do so, but use a waterbath for the tank. If you dilute developer, mix water accordingly to get reasonably close, it's easy. If you get higher, ie 25 instead of 24, you can also easily reduce the temperature. Get a film can, put some water in it and keep it in the freezer. You now have an ice cube that doesn't melt. Obviously, that trick can be used for stock solution, if you don't dilute your developer. You should also use a waterbath to cool stop - fixer and mix a large quantity of water for washing at the desired temperature. It's very easy to have a process with temperature deviations at +- 1 degree C.

 

[Ian Grant]

Second Mr Ymouse's work flow - I live in sight of Greece . I regularly work at 26°C with no problems. Just be much more careful to keep all steps at the same temperature, including the washing.

Tropical developers were needed for older poorly hardened films, might be useful with EFKE/Adox films still though, but I use Pyrocat which is semi-tanning (hardening) anyway.

Ian

 

[Neal]

Dear Krzys,

In the '80s I regularly processed Tri-X (400) in Perfection XR-1 (It was a speed increasing developer that really did work quite well) at 30°C. I had reticulation problems once but because you won't have to apply heat to get your wash water up to an acceptable temperature that will not be an issue for you.

Neal Wydra

 

[nworth]

I've used D-76 with at water temperature around 27C and an air temperature above 30C without a problem, but I didn't like doing it. With a water temperature above 30C, a tropical developer may make some sense. I'm not sure what effect adding sulfate to D-76 will have on developing times. Some research or experimenting may be in order.

The formula for DK-15 is unlike anything else I have seen. It is a metol only developer buffered to a rather high pH and having a lot of restrainer. Metol only developers normally have low contrast, but the high pH may counter that. The high sulfite content hints at full or high film speed and fine grain, although the high pH may counter the fine grain a bit. I can see how it might be a quality developer for the films of the 40s and 50s, but I would be curious about how it would work with modern films.

 

[juan]

I regularly work with water temps of 27-30C. I played with tropical developers, but found that Pyrocat HD, diluted 1.5-1-150 used with minimal agitation worked just fine. Maybe the developer tanning helps. I also found that there was less danger of negative damage if I just let all the solutions come to room temperature and adjust my times accordingly.
juan

 

[ninchi]

can you tell me more about tropical developers...i have an examination question but i can't find anything about that...
thank you a lot
nina

 

[Ian Grant]

Easy just add Sodium Sulphate see the 1st post, taht stops the gelatin swelling, Easy

Ianm

 

[CBG]

One issue comes up when processing at high temperatures, very short developing times. It gets difficult to process consistently with very short times. A more dilute developer than ordinary will lengthen developing times. Think D-76 1+1 or 1+3 etc.