Dongrappo
Hello everyone
When I made my first enlargements the day before yesterday, and used some very old Ilford fixed-grade paper in the silk-gloss finish for these initial tests, well, it happened that I placed the photographic paper on the frame the wrong way round three times and subjected it to exposure through the underside of the paper, as even in daylight it is almost impossible to tell the two sides apart. In the dark, it’s even harder to tell, and they feel almost identical too.
Well, even during the exposure, when the emulsion side was facing the frame, the result was an out of focus image that was about 2–3 stops underexposed.
Now the question. Surely, even with the correct exposure, with the emulsion facing the lens, there would still be a certain amount of contaminants (perhaps -4 to -6 stops with this paper) in the image, precisely because of this image reflected from the backing board/frame, wouldn’t there?
Question: Wouldn’t it be better to place a black backing (cardboard) under the photographic paper during exposure?
Does anyone here have any experience with this, or am I being too fussy?
Best regards,
Werner
MirkoBoeddecker
Hello Werner,
You’re absolutely right. However, with baryta papers, the backing is so thick that the effect can be disregarded.
With PE, using a black backing board can visibly reduce the halos caused by reflected light.
When doing the maths, always bear in mind that the light has to diffuse twice: first to the backing board and then back through the backing again!
I’ve wanted to build a frame with fixed masks for years, and if I ever get round to it, it would have a dark grey backing board.
That way, you could also stop people from being too sharp when it comes to the frame and ignoring the thickness of the paper ;-)
Best regards,
Mirko
Wolfgg
Hello Werner,
That was already a problem 50 years ago, especially when PE papers first appeared and stood out because of their particularly thin backing. It wasn’t so much a question of out-of-focus areas, but rather that the format markings on the backing board were faintly visible in the image!
A simple test: take a test strip and place black paper underneath half of it. If the two sections of the image look different, you’re right.
Incidentally, with many papers, you can distinguish the coated side from the reverse side by sound, by running your finger lightly over it (right next to your ear).
Regards,
Wolfgang
Dongrappo
Right, back from a party and then such helpful replies.
Great that my somewhat chaotic question was understood after all! :-)
Many thanks for the feedback.
The test with the dm test strips is really easy to carry out. A sharp, highly detailed image with high contrast would be best.
I’ll give that a go when I get the chance and I’m curious to see if there’ll be a noticeable difference. But I can well imagine it. Many thanks for the tip.
As I’ll likely only be working with PE papers for the foreseeable future, this could well be a relevant issue for me.
Working with the frame in general – well, I’ve still got a lot to learn there!
In hindsight, good preparation and set-up for frequently used formats would probably make things much easier. I’ll have a look into that.
So, with my Paterson grain sharpener (or whatever it’s called), I can hardly see any difference on Ilford PE papers, regardless of whether I focus on the grain with or without paper thickness, and that’s even at f/2.8.
I suppose I’ll see when my eye is better attuned to darkroom work.
Many thanks for the replies and warm regards,
Werner
