MatthiasStark
Hello everyone,
Since no one on the rival forum seems to have the nerve to answer my question, I’ll just give it another go here. Perhaps this forum isn’t quite as sleepy as people always make out.
I’d be interested to know whether diffuse pre-exposure for contrast diffraction works with RA-4 paper in a similar way to black-and-white paper. Perhaps someone has already tried something like this; otherwise, I’ll probably have to test it out for myself.
I’d be very grateful for any experiences or ideas.
Best regards,
Matthias
Gast
Hello Mathias,
In every large-format lab and every minilab, colour paper has been pre-exposed for years. In the past using the EP-2 process, today using the RA-4 process. In the colour positive process, this is the only way to balance out contrasts to a certain extent. This is referred to as ‘gradation diffraction through subliminal pre-exposure’. In a professional lab or at home, you can choose between papers with different contrast reproduction – Kodak Portra, for example, is available in a portrait variant. This is, of course, not the same as multigrade paper in the black-and-white process.
You will therefore need to test individually how the RA-4 material reacts to pre-exposure in your home lab. Usually, you perform the exposure in Zone I or II – simply slide the diffuser disc in front of the enlarger lens and you’re ready to go. It’s possible that you may need to adjust your base filtration. Give it a go – and do share your experiences with us. Here and on the competitor’s forum.
Best regards,
Stefan
MatthiasStark
Hi Stefan,
Thank you very much for your quick reply. At least now I know that the chances of success are good. I already know how to pre-expose, I just wasn’t sure whether this would work without any problems with RA-4 or whether there would be too much colour shift.
Best regards,
Matthias
