goldian
Member
Would anyone be able to help point me to a source of Leica filter factors - just bought a set (yellow 0-3, green, orange, red, blue) but oddly i cannot easily find a set of exposure adjustment factors
Any help much appreciated
Many thanks
Ian
Any help much appreciated
Many thanks
Ian
Roger Hicks
Veteran
Dear Ian,
Filter factors are not a constant, as they depend on the film sensitivity (some films are much more red sensitive than others) and the subject matter (think of a red filter with a blue sky, or with a red brick building), but good starting points are 1.5x for blue, 2x for medium yellow, 3x for green, 4x for orange, 8x for red.
When in doubt, err on the side of over-exposure.
Cheers,
R.
Filter factors are not a constant, as they depend on the film sensitivity (some films are much more red sensitive than others) and the subject matter (think of a red filter with a blue sky, or with a red brick building), but good starting points are 1.5x for blue, 2x for medium yellow, 3x for green, 4x for orange, 8x for red.
When in doubt, err on the side of over-exposure.
Cheers,
R.
ChrisLivsey
Veteran
You have to admire him for some things:
http://www.kenrockwell.com/leica/filters.htm
Note also the intelligent note: with black-and-white films of the 1960s.
which reflects Roger's comment on variability with the film spectral sensitivity, and the range of factors quoted for eg Red again reflecting Roger's comment.
http://www.kenrockwell.com/leica/filters.htm
Note also the intelligent note: with black-and-white films of the 1960s.
which reflects Roger's comment on variability with the film spectral sensitivity, and the range of factors quoted for eg Red again reflecting Roger's comment.
goldian
Member
Many thanks all very helpful
Ian
Ian
shortstop
Well-known
Hi,
I recently purchased two chrome Leitz E39 filters.can anyone tell me if he mounted chrome filters on black summicron?
Chrome filter thread can scratch the thread of the black Summicron?
Can I screw them without scratching the thread?
Thanks
Antonio
I recently purchased two chrome Leitz E39 filters.can anyone tell me if he mounted chrome filters on black summicron?
Chrome filter thread can scratch the thread of the black Summicron?
Can I screw them without scratching the thread?
Thanks
Antonio
Roger Hicks
Veteran
ChrisLivsey
Veteran
Antonio
A touch, I mean a touch, of Vaseline (trade mark) white soft paraffin or candle wax will lubricate enough to ensure a smooth attachement, unless either thread is damaged. I mean a touch!!
A touch, I mean a touch, of Vaseline (trade mark) white soft paraffin or candle wax will lubricate enough to ensure a smooth attachement, unless either thread is damaged. I mean a touch!!
Roger Hicks
Veteran
Dear Chris,
Or indeed, going around the thread with a SOFT (ideally 6B) pencil lead.
Cheers,
R.
shortstop
Well-known
I confess that my concern seemed excessive. But I see that the solutions that you suggested (both very cool) show that I was not the only one to ask myself the question. Thank you very much for the suggestions. that of graphite fantastic!
Best
Antonio