Film Matter: Clearing Out Old Film Stock and the Right Soup

Dear Readers,

You probably expected another part of the sequel Building a small exposure meter, right? Unfortunately, I had a major headache with the purchased digital panel voltmeter as the display for the meter. It looks like a shitty electronic component, with a weird output, so I need first to find out where the problem is, or another voltmeter....But at least, the circuit (with some minor modifications) performs well, with an even lower error as I calculated. So expect to see the final part of the build next week (or a week after). 

The "breadboard" version of the exposure meter works well, but I am still in search of a usable panel meter.

And these are my very last outdated films from the "old good days".

While shuffling my photo stuff, I came across a bunch of films I put out of the freezer a few months ago with the intention to shoot these films at last...trouble is, all 4 films are more or less of the »specialty« type-very high or very low sensitivity, and one is for tungsten light as well. But all of them were venerable emulsions back in the day. So I'll need to pay some respect to them when shooting. The EPT 160T (slide film) will be most likely used when I find some nice happening, like a concert, same for the Tmax P3200. As for the APX25 and the »holy« TechnicalPan, I am not really sure when, but they'll be used probably for some landscape stuff. Ok, this is my business what I should do with these films, but when it comes to develop these BW films, we all have the same problem - in which soup we shall develop the old outdated stuff. For the TechPan and the APX25, I'll probably just use Rodinal or its »clone«, the R09 developer (quite similar, but closer to the original pre-WWII formula), except that for the TechPan I shall use a highly diluted solution. Rodinal is quite a flexible chemical, since you can mix it with a buffer (the plain formula is highly alkaline, but it's not buffered), most often with borax, giving a more gentle development. If you haven't tried Rodinal (or R09) yet, give it a go, especially for low- or medium-sensitivity films. Here you can also find the link to the legendary Unblinkingeye article (written by Ed Buffaloe) on Rodinal and its flexibility.

As for the P3200 (very prone to fog), I am not quite sure how to »soup« it, but most likely I will mix up the post-WWII developer formula, reportedly invented by the Czechoslovak ing.Koblic (a great photographic inventor BTW). After the war, there wasn't any fresh film stock available in Europe (and we had other greater problems then), but only old, mostly highly outdated film stock. So ing.Koblic came out with the formula to preserve film's sharpness and keeping down film fog (to be expected otherwise with old film).  Here is the formula: 

Metol - 4 g
Sodium sulfite (anh.) - 16 g
Disodium phosphate (.12H2O) - 4 g
Borax (sodium tetraborate) - 8 g
water to make - 1000 ml (pH around 8.5)

Here disodium phosphate acts as an antifog agent, in contrast to other developers where potasium bromide is usually used. As for the developing time, one should find him/herself the most appropriate time, but reportedly up to 15 min should do the job, and the developing time shouldn't be so critical (in case of a too long devlopment). Here is also a link to APUG where this developer has been discussed a bit, but not too much unfortunately.

My bottom line above all this is: I am always fascinated how many developer formulas have been invented over the decades, some simple and some (many) very complex. In the end, we often come back to the simplest ones, since they work so well (and Rodinal is just one example). It never stops to fascinate me how can such a (relatively) simple black-and-white chemistry produce such outstanding results, over and over again.

Mitja