Alberto,
The 'increased extension' for IR is , I believe, is one quarter of
one percent of the distance from
the film plane to the nodal point of the lens in use. In other words
focus such that the
front of the lens extended that much more from the 'visual' focus
observed 'through' the viewfinder.
Ken
On 29-May-12, at 8:45 PM, Alberto Tirado wrote:
Hello, everybody.
I just bought a Tiffen R87 filter and made a couple of test shots.
My rudimentary measures say there is a 16 (yep, sixteen) step
compensation, which is substantially more than I had read and
expected. I still have to test it more under different conditions,
but If I want interior or studio shots, or even live subjects, then
I'll be in trouble with such density. I may become the most famous
IR rocks photographer! ;)
Anyway, the main thing I would like to ask the forum is this: is
Depth Of Field the same in IR than it is in visible light?
Incidentally, I now remember the lenses of yore had a red mark that
placed infinity a bit farther than visible. I guess I''ll have to
practice a lot this weekend! ;)
BTW, I use a Canon Digital Rebel. I have an XT and bought a T3i
(but still in the box).
Any comments and advice to this curious IR neophyte are welcome.
****************
Alberto Tirado
Quando omni flunkus moritati (R. Green)
