huehnerhose
Hello,
I’m having a problem with the exposure times for Polywarmton – mine are around 40–60 seconds (13x18).
I work with
manual split-grade and need to perform exposure at 5 for about 40 seconds and at 0 for about 30 seconds, which I think is a bit long for 13x18. With Foma Variant III, the times are usually under 15 seconds. (both PE, Foma glossy, PWT matt)
I’m using a Durst M605 with a 6x6 condenser, a 150W opal lamp and a Rodagon 50mm/2.8 stopped down to f/5.6. KB negatives in a 6x6 glass stage. Filtering is done with insert filters.
I did consider the developer, but I’ve just made a fresh batch of Eukobrom – nothing has changed.
The real issue now is the exposure times for 18x24. The 5-sheet exposure time is around 1–2 minutes.
Are these long exposure times normal for this paper? Or is something wrong here?
Regards
Sebastian
Gast
Hi Hühnerhose,
PWT is a bit slower than other papers, but it’s not that slow either.
Using the same method and also a black-and-white negative at f/5.6, I get around 15–25 seconds per filter, and that’s for 18×24!! Possible errors that spring to mind:
- The Eukobrom concentrate has gone off, or
- You’ve accidentally screwed the density screen in
Otherwise, try the search function; I can recall a thread on the same topic – it was a relatively long one.
Good luck finding the fault, and best regards,
Taher Askar
SamuliSchielke
In my experience, PWT (and Fomatone too) is about two stops slower than Fomaspeed/Brom. According to the technical specifications, PWT is 160 ISO and Fomabrom Variant is 500 ISO (unfiltered!).
Samuli
SimonWeber
Well, with the same setup (M605, etc.), my exposure times are quite long too. f8 or f11 at 24x30cm: at least 30–40 seconds, but often 120–150 seconds (manual split grade).
Why is that a problem? (???)
Simon
Gast
I can well imagine that, in this case too, the use of a 35mm lens would result in significantly shorter exposure times.
Best regards,
Otto Beyer!
Wolfgg
Warm-tone paper has almost exactly a quarter of the speed of Ilford Multigrade 4. Warm-tone papers need to be less sensitive because the warm tone is caused by smaller silver crystals compared to neutral-tone paper, and as with film, the rule is: smaller silver crystals -> lower speed.
Best regards, Wolfgang
Wolfgg
One more thing: contact printing from 18x24 to a 6x6 frame means the base plate brightness is equivalent to a 6x6 negative printed on 45x45 cm paper! Exposure times of over 1 minute are normal with warm-tone paper. So, as already mentioned, a contact printing condenser is essential.
For contact printing, I’d also leave out the glass; I’m sure you have glassless inserts as well.
Regards, Wolfgang
arothaus
Hello,
If the exposure times are usually around 10 seconds and are now around 40 seconds, that’s exactly two stops longer. So everything’s fine.
Best regards,
Andreas
huehnerhose
Thanks to you all for your replies!
I’ll try to answer this bit by bit:
I have a condenser, but it doesn’t have any density for threading.
Unfortunately, I don’t have a KB condenser, nor do I have any glass liners. I don’t really have a problem with the times as such – as long as I’m not working under time pressure, it’s fine – it just struck me as odd, hence the question.
I don’t really think the Eukobrom concentrate has gone off. It still dissolves beautifully and looks just as it did on the first day – which wasn’t that long ago.
So, in conclusion: everything’s fine :blink:
Regards
Sebastian
Wolfgg
But it’s just occurred to me: a 6x6 condenser is designed for 80mm lenses; if you use it with a 50mm lens, quite a bit of light will pass right past the lens, and you might even end up with uneven illumination!
So it’s not just that the 6x6 condenser illuminates too much; the entire light path is then incorrect.
Regards, Wolfgang
Gast
Hi
Yeah, that’s just the way it is – you have to expect these long exposure times. It annoyed me at first too. But I suppose that’s the ‘price’ you pay for the best warm-tone RC paper I know.
Exposure times of 60 seconds at f/5.6 are apparently just standard with a condenser enlarger.
The advantage is that you’ve got plenty of time for dodging and so on.
Regards,
Martin
Gast
... The 6x6 condenser on the Magnifax produces unevenly exposed prints when using 35mm negatives. From experience, I agree with Wolfgang on that. I’ve no idea if that’s the case with other enlargers, but I’d definitely check it out.
Replacing the opal lamp with a more powerful one might do the trick, though it’s bound to generate more heat – and the energy suppliers won’t be too pleased about that.
Best regards,
Ronald
Gast
... sorry, I don't think it'll be possible to go over 150 watts. I missed that.
Wolfgg
If you’re handy, you could try replacing the opal bulb with a 230V, 100W or higher halogen reflector bulb. On many units, you can adjust the height of the bulb and position the shorter halogen bulb accordingly.
Regards, Wolfgang
