MarcS
Good evening,
I’d like to make my own large-format colour slides (13x18) using my enlarger.
Can I simply use my Beli to measure the light from the colour negative I’ve loaded
and perform exposure accordingly (approx. 4–6 seconds for 100 ASA film), or does it not work like that,
or is there anything else I need to bear in mind?
I’d be grateful for any tips – the film isn’t exactly cheap ;)
Best regards
Marc
CPD
Hello Marc,
As you quite rightly pointed out: "Film isn’t cheap." And that’s probably where it will all fall apart!
First of all, you need to know whether the enlargement is to be made from a negative or a slide. There used to be special materials for both, but unfortunately they are no longer available. Pre-exposure, for example, helps counteract the inevitable loss of contrast during enlargement from a slide onto standard slide paper. And that’s where you’ll just have to experiment. To achieve reasonably practical exposure times, you’ll need to work with neutral density filters. The enlarger must be completely light-tight, otherwise you’ll have stray light wandering around the darkroom, which will fog your rather sensitive photographic material. I’m afraid you can probably forget about using the Belis – but do give it a go. I’m rather pessimistic: with longer exposure times (due to the neutral density filters), you’ll get colour shifts caused by varying black shield effect in the individual emulsion layers; with short exposure times, you’ll need a shutter on the enlarger.
It’s doable – professional labs used to do it in the past – but it’s not exactly straightforward. On the other hand: don’t let me put you off! :rolleyes: Maybe you’ll get a few more optimistic tips. B)
Ciao!
CP
CPD
One more thing comes to mind:
The best thing to do would probably be to get yourself a simple 13x18cm camera and a slide-copying attachment. You won’t be able to avoid pre-exposure with that either. However, you’ll find plenty on this subject in photography books from the 1970s.
As for film stock, the situation is rather bleak in this format. It’s slightly better, though not by much, with 5x7-inch. So if you’re going for cassettes, go for 5x7-inch.
Or go straight for 8x10-inch.
Ciao!
CP
MarcS
Hello Marc,
As you quite rightly pointed out: "Film isn’t cheap." And that’s probably where it will all fall apart!
First of all, you need to know whether the enlargement is to be made from a negative or a slide. There used to be special materials for both, but unfortunately they’re no longer available. Pre-exposure, for example, helps counteract the inevitable loss of contrast during enlargement from a slide onto standard slide paper. And that’s where you’ll just have to experiment. To achieve reasonably practical exposure times, you’ll need to work with grey filters. The enlarger must be completely light-tight, otherwise you’ll have stray light wandering around the darkroom, which will fog your rather sensitive photographic material. I’m afraid you can probably forget about using the Belis – but do give it a go. I’m rather pessimistic: with longer exposure times (due to the neutral density filters), you’ll get colour shifts caused by varying black shield effect in the individual emulsion layers; with short exposure times, you’ll need a shutter on the enlarger.
It’s doable – professional labs used to do it in the past – but it’s not exactly straightforward. On the other hand: don’t let me put you off! :rolleyes: Maybe you’ll get a few more optimistic tips. B)
Ciao!
CP
Hi CP,
thanks for the reply; let me briefly explain the purpose:
I need 13x18 slides for a large-scale xenon projection. I had such slides made in a lab years ago, but they cost over €100
Wolfgg
Hi Marc,
Enlarging a negative onto Diaplan film does not produce a large-format positive, but a large-format negative. You’ll first need to make (or have made) a slide from the colour negative. This slide must also be soft-focus, as the gamma of transparency film is around 1.5. Or do you want to take the risk of developing an E6 transparency into a negative? A lot of material can go to waste before you end up with something projectable. A potentially viable, cheaper option: enlarge the negative onto RA4 in the desired size and then have it colour-copied 1:1 onto a transparent backing at a copy shop.
Regards, Wolfgang
CPD
I checked with 'my' lab earlier. They no longer offer this service; apparently, the necessary film materials are no longer available.
Bye
Wolfgg
Excerpt from Agfa’s product range overview of May 1973, section “Colour processing films”:
1) Agfa Positive Film M for the production of slides from masked or unmasked colour negatives
(Formats 9 x 12 to 50 x 60 cm and 105 cm x 10 m)
2) Agfacolor-ZN film for the production of colour negatives from slides (intermediate negatives)
(Formats 35mm x 10m DP or 25m DP and 61.5mm x 15m)
3) Agfacolor reversal film for the production of colour slides from slides (slide duplicates)
(Formats 35mm x 50m DP and 61.5mm x 15m)
(End of excerpt)
To the best of my knowledge, of these three film types, only No. 3 is still being produced (Kodak EDUPE and Fuji also have one). And that is solely because of Hollywood & Co., so that they can save their supposed ‘old treasures’ from decay.
So anyone bringing in film types No. 1 or 2 these days is in a tight spot.
Regards, Wolfgang
MarcS
Hello Wolfgang,
Thank you too for your information. The idea of a 1:1 copy from a copy shop is a good one; I’ll give that a go as well, although I
fear the film (transparency film) won’t hold up against the 7kW projector (I’ve already tested slides). I’ll
just have a go at it.
The Kodak EDUPE would be just the thing for exposure in an enlarger, but I haven’t found a supplier
for that here either.
I’ve contacted Martincolor; unfortunately, they don’t make slides anymore either, but they do work with Duratrans. There’s also
Duraclear, a completely transparent colour photo paper, which might work for my purposes,
but I can’t find any suppliers online.
For black and white, I’ve already tested ADOX Displayfilm, which works well too.
Regards
Marc
Wolfgg
Hi Marc,
Given the limited choice of materials available these days, perhaps a digital approach would make more sense – not just simple inkjet printing, but also specialist techniques such as sublimation printing.
Best regards, Wolfgang
cfb_de
Sublimation printing.
Cool idea. And then we’ll warm it up a bit in a 7kW projector and suddenly we’ve got a gradient image :)
Best regards,
Franz
Wolfgg
Hi Franz,
I do hope that a projection monster like that has a decent IR cut filter and a powerful fan for the original.
But you’re probably referring to sublimation printers anyway, which transfer ink from a ribbon onto paper using low heat. I was referring to a different principle, which unfortunately has the same name. In this process, an Epson inkjet printer is usually converted to use sublimation ink; it prints onto a transfer material, from which the image is then transferred to the final material at around 180°C using a heat press. Images produced using this method can withstand much higher temperatures. You can find out more by searching for ‘sublimation printing’.
Regards, Wolfgang
MarcS
I do hope that a projection monster like this has a decent IR-blocking filter and a powerful fan for the original.
The magazine is well cooled, but still gets quite warm; my older slides are already quite warped...
But what about Ilfochrome Clear, actually? I’ve asked LeBon about where to get hold of it and am still waiting. That might
be suitable for projection as well and is relatively easy to handle, isn’t it?
Regards
Marc
Wolfgg
Hello Marc,
If the material on a clear backing (not the opaque one) is still available, that would also be an option; it’s still listed here:
http://www.ilford.com/de/products/ilfochrome/back-lit.asp
One drawback, however, is that the smelly bleach containing sulphuric acid makes the processing unpleasant, so it cannot be used in the tray, but only in sealed containers such as paper developing tins.
But: it is a positive material! As with E6 sheet films, an intermediate slide with the correct contrast must first be created from the colour negative; the correct contrast is crucial here, otherwise the result will look terrible on the screen.
Regards, Wolfgang
MarcS
I’ve heard from Le Bon… the Ilfochrome Classic is available in Clear as CC.F7
but unfortunately only in 50x60cm, 25 sheets, at the exorbitant price of €650 net…!!!
The Ilfochrome is also suitable for projection, as the material is said to be relatively strong.
The overhead film from the copy shop is definitely not suitable, in any case.
Regards
Marc
