As some of you may be aware, I have recently converted a DeVere 54 enlarger to LED lighting using the tri-colour PCB from an LED stage light.
Last night I finally got round to making some prints and I am very pleased with the results...... which I can't show you yet as I didn't have enough fixer!!! I made up a weak mixture with the little I had but all the prints I made have darkened. I will order some more and make some prints which I can show here.
Anyway, despite this, these are my observations:
The first print I made was with all three colours (red, green and blue) and all appeared to work well. I was worried about the spread of light and the diffusion not being enough and I was expecting to see the corners lighter than the centre i.e. reduced illumination at the edges. Actually it looks very even across the whole print so I don't think there is anything wrong with the diffusion I have used.
I then tried prints with just the green and just the blue LEDs. Both of these worked very well and showed low and high contrast as expected. Not at the extremes of 0 and 4 or 5 as could be achieved with normal filters but perhaps 1 to 3 or 3.5 (just guessing here).
The thing which surprised me was that for a similarly dense print I needed just over twice the time with green as I did with blue. I was expecting it to be the other way round.
Another surprise was the amount of light. As a guide, printing a 5x4 negative up to 10 x 8 with the lens two stops down, I could get a good print with around five seconds exposure time. I may increase the diffusion a bit to both reduce the level and to be sure of good light spread (even though I have already stated that it is ok!).
I will update this thread with some pictures when I get them.