Good Morning,
I am building my new lab for printing.
I bought a big sheet of gelatine filter at LeeFilter's. It is a 789 Blood
Red Filter
https://www.leefilters.com/lighting/colour-details.html#789
I guess it is a good one for lighting the lab without damage the
photographic papers.
But I have a question : which quantity of light (Lumen) can I use behind the
Blood Red Filter without veiling my photographic paper ?
In my books, I find only the wavelength but nothing about the quantity of
Lumen.
Does somebody know something about this point ?
Many thanks in advance for your answer,
Best regards,
Thierry ARNAUD
(France)
