fritzsiepen
Hello!
I’ve read quite a bit about whether it’s possible to enlarge a negative onto cyanotype paper.
However, the following problems have always been mentioned:
- The lamp needs to be modified to increase the UV component
- The light output isn’t sufficient, or the exposure would take days.
- The enlarger lens only allows a small amount of UV light through.
Now I’ve had the idea that perhaps one could use a flash.
Flash light is very similar to daylight and therefore probably has a high UV component, doesn’t it?
If you were to install a strobe with a high flash frequency in the enlarger, it might work.
Has anyone ever tried this?
Thanks!
AchimBauer
Hi Fritzsiepen,
I don’t have any experience with this sort of thing, but I always think it’s great when people plan something unusual and think outside the box.
Off the top of my head, I’d say try experimenting with a high-intensity sun lamp – often called a ‘face tanner’ – or with a UV lamp from the garden pond range, the sort you use to make suspended algae clump together so you can filter it out. Of course, that would only be possible with a lot of DIY effort.
But I think the real sticking point is the lens. It might be, but it doesn’t have to be. Because optical glass is often different from normal window glass. Basically, UV light – i.e. short-wavelength light – is converted into IR light – i.e. long-wavelength light – when it passes through glass, and this doesn’t penetrate glass as easily. This is the famous greenhouse effect. In a greenhouse, UV light is absent (with the exception of newer structures using white glass), which is why plants grow taller there, as UV light inhibits vertical growth.
On the other hand, astrophotographers using digital cameras face the problem of obtaining out of focus images because the telescopes are not sufficiently corrected for UV and IR, and therefore require UV and IR filters. So do ask the lens manufacturer which wavelengths the lenses transmit.
Or, if you’re going ‘back to basics’, simply use a standard lens, though this will further increase the exposure time.
But the most important thing is not to get discouraged and to find a way.
Regards, Achim
Urnes
With a flash, you’ll face the same issues as with a lamp. Probably even more so, because with two flashes you’ve got double the light output. To double it again, you’d need four, then sixteen flashes.
How big do you want it to be? Sure, you could transfer it to large-format film. But you could also try using a paper negative; I haven’t done that yet, though. What works, of course, is scanning the negative and printing it onto transparency film. Too digital and too much hassle with the equipment? Then there’s always the copy shop. If the paper backing of a paper negative has too high a density, I’d have it transferred onto A3 overhead film at the copy shop. That works very well, depending on the subject.
But of course it’s more fun to expose the negative directly onto an 11x14" sheet or similar :D After all, that’s the whole point of contact printing.
Regards, Sven.
cfb_de
Why don’t you just make a large negative and then contact print it?
This works for both analogue and hybrid processes.
Best regards,
Franz
fritzsiepen
It’s more expensive, but probably the better method ...
