Eukoton and speed papers

ravebenni · 2008-04-13T19:51:28+00:00

Hallo, ich habe mal wieder in der Bucht gefischt: Eine Flasche Eukoton und eine kleine Packung AGFA Brovia Speed BN 310 RC 3. Eukoton ist ein Schnellentwick...

ravebenni

Hello, I’ve been fishing around on eBay again: a bottle of Eukoton and a small pack of AGFA Brovia Speed BN 310 RC 3. Eukoton is a rapid developer designed for papers containing built-in developer substances. It works perfectly with the AGFA paper; maximum density is reached after three seconds. However, as I don’t have much experience yet, I wanted to try other papers as well. I then tried it with Foma Variant III, but nothing happened at all. The Foma paper is perhaps two years old and develops perfectly in N133. However, the Impex catalogue states that the paper contains embedded developer substances. So why isn’t it working anyway? :rolleyes: P.S. It seems to me that with Eukoton and the aforementioned Agfa paper, the blackness intensifies slightly after development. Is that just my imagination, or is there a chemical explanation for it?

MirkoBoeddecker

Hello Benjamin, Fomaspeed Variant is only suitable for use with an activator to a limited extent. MCP is a genuine rapid-access material. With Foma, you’re therefore better off sticking with N113. The other effect you’ve observed is what’s known as post-darkening during drying. All papers (especially PE) exhibit this property to a greater or lesser extent. However, it’s actually rather undesirable, as it has to be factored in during printing. The less a paper is prone to this phenomenon, the better. Best regards, Mirko

wschwetz

Hi Mirko, That darkening during drying can be a real nuisance at times. As you’re likely to have a good overview of this, which PE papers are most prone to it and which are least? Wilfried

MirkoBoeddecker

Hi Wilfried, I haven’t analysed this scientifically yet, but my impression is that Fomaspeed doesn’t really cut it here, unfortunately. The new Easy Print is better, and Ilford Multigrade IV and MCP are even better. But the effect always occurs. Gelatin is, after all, a complex colloid. I do have the feeling, though, that sometimes it also ‘depends’. That is, on drying conditions and chemicals. But that might just be a hunch, as lighting conditions aren’t always exactly the same either. It certainly can’t hurt to see the effect for yourself. So simply cut a print in half, re-wet one half under identical lighting, and compare. Then you’ll know by what percentage you need to print lighter to avoid the effect. Best regards, Mirko

PeterVolkmar

Hello, Given that the Foma film is so striking, I can only agree! However, the effect also occurs with baryta paper. The effect is slightly different there and difficult to assess, as the blacks are richer on wet baryta paper; it is mainly the light areas that darken further. That’s why this work is worthwhile: the dry-down effect . Best regards, Peter

cfb_de

Hi Peter, Exactly. That should clear up any questions. To make it even clearer for the PE enthusiasts: it works exactly the same way! And when it comes to hot drying versus a clothesline, certain PE emulsions (e.g. the old Amaloco Varimax, Efke Varycon or virtually any new emulsion from various brands) can spark lively discussions about ‘blooming’. Simply melt the emulsion properly during drying and the issue is sorted. Then you’re left with only the “dry-down” effect, which you can control yourself. I’m sure everyone is familiar with my favourite paper from the host’s company. There are still a few metres left on the roll; I know the dry-down of this paper, and I know the changes in speed and tonality over the first year after casting and thereafter. I’d love to have something just like that again. At a similarly attractive price. Best regards, Franz