Durst VLS 500 settings for Variable Contrast Paper

[angusparker]

I recently bought a Durst VLS 500 head as a compliment to my current CLS 501. The info on what settings to use for Ilford Multigrade IV was thin on the ground, mostly because the head was designed when that paper didn't even exist! In any case, I did find a single post with some settings which I interpolated somewhat for half-grade differences. Take this with a pinch of salt as it may be passing on poor information. I'll give it a try and see what happens. Does anyone else have a better idea?

VLS500.pdf

[MartyNL]

I think this will be an excellent starting point for the VLS 500. The VLS 501 replaced the 0-100 scale with the familiar fractional scale.

The next step would be to speed match the filter settings. I attempted this and discovered a few points;

1. Speed matching appears to be paper specific. Not too much of a problem if you don't use too many varieties of paper.

2. Speed matching doesn't appear to be linear across all grades. So extrapolation can't be relied upon.

3. Purely following the science/theory doesn't always give the desired 'real-life' result on paper. Especially at both ends of the filtration grades, I found the resulting prints less than desirable and I needed to adjust/compensate exposure times in order to get tones much more useful to a printer and to that of a 'real-life' print.

4. I'm uncertain of speed matching consistency across all Durst L1200 diffusion enlarger heads/models.

[MartyNL]

Here's a couple of images showing what I mean.

Previously, I'd tried using a meter under the lens to 'guarantee' 'identical' exposures due to changes in filter grade. It didn't work. As in, I got results that I would never use or find helpful as a printer.
So I resorted to test-strips in 1/12th increments to get better information, for me and my way of working. (Boxes refer to 'way beyond monochrome' f-stop printing table in 1/12th of a stop.)