Hi all, I am looking for a ND filter for my enlarger. I have an Opemus 5a. The filter drawer holds filters of 7x7 cm (2.75x2.75 inch). The reason is that I have a new RHD Analyser Pro and want to calibrate it to my papers. For this, I need to reduce the light to get times that I can work with. (For those of you who are familiar with the Analyser, the first reading gives me a time of 3.41 seconds, but I need to achieve a time between 10 and 20 seconds, so a filter of about 1.5 stops should do fine if I am not mistaken. Yes, the lens is stopped down to minimum aperture and the enlarger head is in its highest position.). Any help/offer would be greatly appreciated.