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brad goda said:like "hot mirror NDIR filters"
use Fuji ND filter behind the lens.
Magenta casts and ND filters are usually due to IR leakage in the filter. This is common, most strong filters let a lot of IR through, and most older cameras register that IR in the blue and red channels, making magenta. A good "hot mirror" IR filter should clear it right up. And it will improve your foliage colors, too.
Every camera responds differently to variable ND filters (crossed polarizers, whether you cross your own or use something like the Heliopan) and also to actual ND filters. ND filters "leak" a lot of IR light. That's why crossed polarizers are sometimes used as improvised IR filters. Crossed polarizers have an additional problems that a "normal" ND filter, a single piece of dyed glass, won't have, in that they also leak UV. Cameras have good IR/UV blocking filters inside, but when you do something like blocking 8 stops of visible light, the leaked UV and IR start to cause problems. IR typically shows as a magenta cast, UV as a blue cast.
neuroanatomist said:Doesn't have to be IR. if you look at the transmission curve for the B+W 3.0, it starts to rise from 'neutral' at about 630nm.
neuroanatomist said:Doesn't have to be IR. if you look at the transmission curve for the B+W 3.0, it starts to rise from 'neutral' at about 630nm.
brad goda said:neuroanatomist said:Doesn't have to be IR. if you look at the transmission curve for the B+W 3.0, it starts to rise from 'neutral' at about 630nm.
ok whatever you say but cinema guys I know all have full line up of hot mirror IR ND filter kits.
I guess they have spent thousands for nothing.
what do i know... live and learn
brad goda said:marsu42
ok good you are finding the info to answer your problem! great info hunting!
RLPhoto said:Buy LEE or schnider optic.