Gast
Hello,
I’m having a problem with the Fomabrom baryta paper. The catalogue states that it is similar to the old OrWo paper and can also be processed under yellow-green light. When I tried this, the entire test strip suddenly turned completely black, even though the exposure time was set quite short—in two-second increments at f/8 and a 75 W lamp for a 13 x 18 cm print. I only got decent results in complete darkness. But even then, I ended up with an exposure time of about two seconds, which suggests a very high speed.
I then loaded a whole sheet in the dark to perform exposure for two seconds and aligned it with a red filter in front.
The result was poor. Ghost images appeared and the photo was far too dark, as if it had already been pre-exposed through the red filter during alignment.
Could it be that the Fomabrom is not properly orthochromatic? It cannot be down to the filter, as all other papers (Agfa, Ilford) did not show any signs of fogging.
How should I process it?
Regards
Thomas G.
RomanJRohleder
Thomas,
The Fomabrom data sheet states the following regarding Duka lighting:
"FOMABROM should be handled and processed under yellow-brown, red or orange
safety lighting with filters (for example, Ilford 902, Osram Duka 50, Durst Sanat, Kodak
OC, Agfa G7, Agfa Y7J, etc.) in combination with a 15-watt lamp. Direct light must be diffused by inserting a matt glass. Because of its high speed, FOMABROM should
not be exposed to this safelighting for longer than 3 minutes and 10 minutes at a
distance of 0.5 metres and 1 metre respectively.”
Also: no yellow-green and always exercise caution.
Have a go at a proper veiling test à la the Ilford "Multigrade Handbook":
<http://www.phototec.de/pdf/im-handbuch.pdf>
Roman
ChristianKolinski
Hello Thomas,
It can’t be the filter, as all the other papers (Agfa, Ilford) didn’t show any fogging.
Don’t let our host hear you say that, he’ll be all over you.
There’s actually a whole section on this in the catalogue and online, have a look:
http://fotoimpex.de/Technik/Fehlersuche/fehlerswpapiere.html
and page 4 in the current catalogue.
The Foma papers need red. Dark red is best. Or no Duka Light at all.
Christian
SamuliSchielke
Dear Thomas,
I often use Fomabrom myself and have never had any such problems. Generally speaking, neither the paper nor the light should be an issue. At least not in general. Although the manufacturer’s data sheet does not recommend it, it is probably possible to process Fomabrom under green-yellow Duka light. However, the paper should be able to withstand short periods under green-yellow light; it only becomes critical after more than 5 minutes, particularly when making lith prints or using slow warm-tone developers.
I think there are two possible causes of the problem.
1. Your darkroom lighting is very bright and/or the red filter on your enlarger isn’t red enough. Or your enlarger is giving off so much stray light that the paper (Fomabrom is really fast, after all) is fogged by it (though that wouldn’t explain the shadow images). But it would have to be very bright for that to happen, as I’ve never had such problems myself.
2. The paper in the pack is damaged, either because it was opened under the wrong lighting or stored incorrectly, or something similar. Did you buy the paper new from Mirko or on eBay? What is the batch number? You’ll need that to check whether other packs from the same batch have the same problem.
You can easily find out whether it is down to the light or the paper, either by doing a veiling test, or by taking a streak of paper out of the pack in complete darkness, developing it, stopping it, fixing it, and only then turning on the light. If the paper is not completely white, it is the second case; if it is, both could be the case.
It’s worth testing, as Fomabrom is a lovely paper that’s generally easy to process and forgiving. Good luck,
Samuli
Gast
Roland,
I hope not; the Agfa G7 you mentioned is yellow-green, and it works for me with the filter.
Whether Foma have come up with something to save costs – such as treating multigrade and fixed-grade films the same way during sensitisation, but forgetting to put that on the packet – why not.
Perhaps you’ve accidentally got the Variokontrast version in your box.
Roland
SamuliSchielke
Hello Roland and Thomas,
It’s highly unlikely that Variokontrast is in there, as it hasn’t really hit the market yet. But if you tell me whether the paper is standard or hard, matt or glossy, and what the batch number is, I can certainly check whether I have the same batch in stock (if the paper is new, it wouldn’t be unlikely) and see how it performs for me.
Best regards
Samuli
Gast
Thanks for the replies.
I’ll quickly retract that theory about the Duka lamp – I’d rather live a bit longer. ;)
Even so, you usually opt for fixed gradations precisely so you can use that greenish light, which I find much more pleasant than red light.
But even setting that aside, I’ve never heard of a red filter added to the Durst enlarger fogging the photographic paper to such an extent that ghost images appear. Has anyone had such an experience?
Perhaps I should splash out a bit more after all and go back to the baryta paper from Leverkusen??? :(
Regards
Thomas G.
ChristianKolinski
Thomas:
Filter age, fade, get scratched, and so on.
How old is the enlarger? A simple piece of
DC-Fix Red or Rubylith – stuck onto the old filter – might be enough to solve your problem.
Gast
Hello,
It is indeed down to the filter. After the exposure of the paper covered with a coin, the image was already clearly visible after just 45 seconds at f/8, whereas the lab lamp still hadn’t produced any fog even after five minutes.
It is rather odd, though; surely the Foma paper must be particularly sensitive?....
Hence my question: what exactly is ‘DC-Fix red’ or ‘Rubylith’? And where can one get hold of such things?
Thanks for your reply.
Thomas G.
ChristianKolinski
Hi Thomas,
Rubylith is a transparent red adhesive film used in the graphics industry for masking print templates and the like. It’s simply a replacement for the old filter.
You should also check for stray light from the enlarger – just to make sure nothing has shifted or that the illuminated aperture ring isn’t making the image appear larger.
Christian
Gast
Hello,
Where can you buy individual sheets of Rubylith? I’d be interested in getting some to cover a screen so I can have a PC in the darkroom.
Anthony
