On Dec 7, 2005, at 2:47 AM, Derby Chang wrote:
http://members.iinet.net.au/~derbyc/index5/05_12_bw/index.htm
The second one (with the "white" tree) has an IR look to it. Is it
some sort of "digital IR" thing? It's very cool.
Indeed, and bit of polarising filter, a bit of PS channel mixin'
and digital IR is yours. I've been interested in doing this for a
while. R72 filters go for over $100 so this is more attactive.
You can get an "IR look" through tonal manipulation, but if you're
not recording IR light it's not IR photography. The only way to
record IR light and separate it from visible light on film or digital
is to use an IR-pass filter.
I've also heard that one can use a piece of exposed negative as a
cheap IR filter. Anyone tried this? I think I have some misloaded
medium format negs lying around for an experiment.
I can't remember whether it was a piece of unexposed, processed E6
slide film or a piece of totally saturation exposed, processed C41
negative film at this point, but I did some experiments with that
some years ago. It produced results similar to the B+W type 092 IR-
pass filter (620nm cutoff), but with a bit more visible light leakage.
Godfrey
