Instoscope
the extinction meter image by Mario Groleau (Image rights) |
Drem Instoscope image by Anssi Puisto (Image rights) |
The Drem Instoscope was an extinction meter in. When viewing thru the ocular one could see a number of letters. The least visible letter was explained on the table which was wrapped around the instrument. The table showed the possible shutter-speed/aperture combinations for the least visible letter.