Analogue enlargement from black and white slide

Stefan · 2014-10-08T08:11:32+00:00

Hallo! Wie erstellt man eigentlich Vergrößerungen vom Schwarzweiß Dia? Umkehrpapier gibt es m. W. nicht mehr. Funktioniert es mit einem Internegativ? Bei...

Stefan

Hello! How do you actually make enlargements from black-and-white slides? As far as I know, reversal paper isn’t available anymore. Does it work with an internegative? That’s how it was sometimes done when printing colour slides, but it’s been a long time. I read something somewhere about developing ordinary black-and-white paper using the reversal process. But the method seemed rather complicated to me. Best regards!

Wolfgg

Hello Stefan, With paper reversal processing, the main issue could well be a chemical one. The most effective bleaching agent, potassium dichromate, is listed on the ‘Cancer Index’. If you’re aiming for as wide a tonal range as possible, you’ll achieve the best quality with an intermediate negative anyway. Make this as large as the enlarger allows. Use film with the lowest possible speed; depending on the slide contrast, the film may need to be exposed more generously and developed more gently. Regards, Wolfgang

Tandemfahren

Harman Direct Positive – I won't say any more. ? Frank

Renate

There is now a reversal process for SW paper. I had the chance to see it in action last Sunday at the fineartforum in Paderborn. It is simple (3 trays) and does not require potassium dichromate. It is due to be launched on the market shortly. € Best regards € Renate

AntiLynd

Expose your negatives onto orthochromatic film, such as the one sold by our host. This should be the simplest method (if you categorically rule out making digital prints). You can develop this type of film under red light in a tray, i.e. by eye. € edit: At Wolfgg’s suggestion, I would point out that a film intended for special purposes naturally requires special processing with a special developer. POTA has already been mentioned as one option. If you don’t want to mix it yourself, you can get it – in some places even ready-made – though unfortunately not at FOTOIMPEX; there, however, the Rollei RLC is mentioned as an alternative. If you’re interested, you can find some background information here under the heading ‘Weiche Welle’: http://www.fotografie-in-schwarz-weiss.de/sw-fotografie/wissen/87-spezialentwickler.html

Wolfgg

Yes, AntiLynd, then you’ll have to tell us how the documentary film should be developed. Because a black-and-white slide film like that has a gamma of around 1.5 and needs to be brought down to about 0.7 so that it works with standard paper (special or normal). So the documentary film needs to be reduced to a gamma of just under 0.5. I actually managed to do this once with Agfa Ortho 25, but only with Pota developer (homemade from raw chemicals). For those keen to experiment, here are the figures from back then: 8 minutes at 20°C, agitating every minute, resulted in N-3 on the zone system; the film had to experience some degree of overexposure. Pota data: Dissolve 10 g of anhydrous sodium sulphite and 0.6 g of phenidone in 420 ml of demi-water (quantity for a small Jobo canister). Phenidone dissolves poorly, so stir for longer (some people add diglycol to help, but it works without it too). The developer is sufficient for 1x 135 or 120. Regards, Wolfgang

KlausWehner

I have been working intensively on the subject of black-and-white slides for years. This is a frequently asked question: how do I get good paper prints from black-and-white slides? The answer is not straightforward. Generally speaking, if you need conventional black-and-white prints, you should expose negative film. Anything else involves compromises. Whether or not to accept these compromises is a very personal decision. A slide is optimised for projection. Due to its high contrast, it conveys a brilliance and presence on the screen that no other medium can match. At the same time, the high contrast ensures optimal differentiation of very fine details. This results in an exceptional impression of sharpness. It is this combination that defines the very high quality of black-and-white slides, and this is why they are so popular. However, this high contrast cannot be transferred to photographic paper without loss of quality. (Many people are familiar with this problem from colour slides). Either the highlights blow out and the shadows lose their definition— or the contrast is reduced so much that the brilliant impression is lost. There is no universally recommended method for transferring a black-and-white slide to a print. It depends heavily on a number of factors. You have to try it out for yourself. I presented the chemical kit for reversal processing mentioned by Renate at Photokina in 2014. At the 5th fineartforum in Paderborn, I demonstrated the function of reversal chemistry for paper in a short (improvised) talk. You can expect similar results to those achieved with direct-positive paper. The advantage is that you can, in principle, work with any type of paper. You always obtain a positive result straight away. The chemicals are simple and safe to use (and, of course, do not contain the highly toxic and banned potassium dichromate). The chemicals can be used universally for films and photographic paper. The formula is derived from my “Wehner reversal process”. Unfortunately, I am unable to reply in the necessary detail at the moment, as I will be away from home for some time. Anyone with questions on the subject can contact me: [url=mailto:klaus.wehner@web.de]klaus.wehner@web.de[/url] I will get back to you as soon as I can. Best regards Klaus