Andreas1
Hello,
I’ve just made an interesting discovery in the darkroom. My exposure times were simply too short, so I placed an ND 0.6 filter between the mixing box and the printing stage. I measured a negative using my darkroom light meter and exposed it accordingly. When I looked at the print, I realised it was far too light. I then tried printing other negatives, but the result was always the same. Far too light. I’ve now removed the ND filter again and found that the prints are just right. I’d calibrated the darkroom light meter without the ND filter back then. Can anyone explain to me why the analyser gives incorrect readings with the ND filter? After all, the filter only reduces the light by 2 f-stops.
Best regards,
Andreas
MirkoBoeddecker
What sort of ND filter is that?
Are you absolutely sure it’s just grey and not perhaps slightly red/orange?
Best regards,
Mirko
Andreas1
Hello,
No, it’s a Lee Polyester ND 0.6 neutral density filter.
Best regards
MirkoBoeddecker
Andreas,
Hmm, do you switch off your Duka light when taking measurements?
If not, it could be down to the ratio of red light to white light, which has now changed due to the ND filter—which, after all, only affects the white light.
However, you should have got incorrect readings earlier on with negatives of varying densities, unless you always use f/8 and have fairly good negatives.
The red light must always be switched off when taking measurements.
Best regards,
Mirko
Andreas1
Hello,
The red light is always off during measurement. Use an RHD analyser.
Best regards
