Postby Walter Glover » 15 Aug 2012, 22:31
Condensor and diffusion enlargers may require different processing times for film due to the Callier effect.
As a rule, dust and spotting is more of an issue with condensor light sources. Having said that, I have generally preferred condensor enlargers. Mind you, I have never delved into point-source.
I did use cold-cathode on a Kamm enlarger and also a Durst Laborator 5x7 back in the 70s. We had to leave the light on all the time and use the red filter to time exposure due tio variations in the glow-up and glow-down of turning the lamp off.
What format are you looking at printing with these?
The colour head could work as a variable contrast diffusion head but I suspect that there are some cold cathodes where differing levels of blue and green may also vary contrast (working from memory).
Cheers,
Walter Glover
"We see things not as they are. We see them as we are."
— Emanuel Kant