On Mar 8, 2006, at 7:52 AM, herb greenslade wrote:
I have one question about the filters used. It would seem that the
Hoya R72 has been the filter most used and recommended. Is this
because it is the most effective of the available filters? Or can
other filters, such as the Cokin 89B or the Ilford SFX filter have the
same results?
Has anyone used a filter other than the Hoya R72?
The R72 effects a 720nm visible light cutoff, which is in the right
range to slip into the bandwidth between most digital cameras' IR
block filter and the typical sensors' ability to record near-IR light.
I have the B+W 092 and 093 filters ... the 092 is very similar to the
R72, just a little more visible light slips in, where the 093 is
similar to the Wratten 87c, very very little visible light slips in.
I found the 092 to generally be more useful for pseudo color IR,
where with the 093 you really are restricted to monochrome most of
the time.
Sony DSC-F707, type 093 + 106 filter stack, the car was painted
bright red:
http://homepage.mac.com/ramarren/photo/PAW2/48c.htm
Sony DSC-F707, type 092 + Hoya G(X1) deep green filter stack:
http://homepage.mac.com/ramarren/photo/PAW3/01.htm
I haven't spent much time experimenting with IR and the Pentax DSLR yet.
Godfrey
