Cathomag/Dichromat

[David Lingham]

I have a Devere 203, fitted with a cathomag cold light head. This was bought in the days of graded paper (pre vc). Recently I had the chance to buy a dichromat head as well. My main reasons for the change were the slow speed of the cathomag for lith printing, and splitgrade printing with below the lens filteration is awkward. My question is; The prints made with the dichro seem have less apparent sharpnees than the cathomag. All other factors ie: film, paper, dev, lens aperture etc. have remained the same. Should this be so? or is it down to advancing years.

 

[RH Designs]

Is the print contrast the same? A lower contrast print can sometimes appear to be less sharp. Using the same filter or nominal "grade" won't necessarily give you the same contrast on the paper with the two different light sources, especially as the spectrum of cold light is quite different to halogen and that will affect the contrast of VC paper. Try bumping the dichromat contrast up a little and see if that helps.

 

[David Lingham]

Richard
Firstly thank you for your reply via the RH site re: my enquiry about the stopclock pro. Regarding the apparent lack of sharpness in my prints made with the dichro. Nothing else in my darkroom process has altered, but the grain in the print looks slightly less defined. Not mushy to the point of being unacceptable. But it made me wonder if there is some accepted wisdom that dichros soften grain in the same way a condenser enhances it. As for the stopclock, Xmas is coming and you never know what santa might bring. Then the fun really will start!

 

[RH Designs]

But it made me wonder if there is some accepted wisdom that dichros soften grain in the same way a condenser enhances it. As for the stopclock, Xmas is coming and you never know what santa might bring. Then the fun really will start!

Cold light heads are closer to diffusion than condenser I think, but yes, condenser enlargers do tend to enhance grain (and negative defects).

Xmas comes but once a year so don't miss the opportunity