U of S | Mailing List Archive | alt-photo-process-l | BL light box 'blues'

BL light box 'blues'

Have recently decided to intensify my interest in non-silver, I constructed my
new UV light-box using 10 BL tubes presently 5 inches above my printing frame.

So that I could use the same negatives for both silver-gelatin, Cyanos and VDB
I switched to Pyrocat as a developer... and I must admit, they do look "sweet".

A few years ago my southern Alberta summer sunlight exposures for Cyanos were
running around the eight minute mark... which expanded to around two and a half
hours in the rather weak December sun.

The exposure times I expected using the new 24" BL tubes are nowhere as short as I had
hoped... Cyanotypes seem to be requiring around 40 to 50 minutes while I have not
yet reached the 'end-point' for acceptable VDB exposures, it seems as if 60 -70 minutes
might be the absolute minimum.

I do not have a stouffer wedge to assist reaching my standard exposure times, my patience is
wearing (as my frustration level rises).

I have just put a VDB out on the deck to enjoy some natural UV rays from the sun
for a time comparison...

Are my BL light-box test exposure times "out of line" with times experienced by others?


Quando omni flunkus moritati (R. Green)