Just to add to this, some / most / a few (delete as appropriate) digital
cameras have an IR filter (to remove much of the IR spectrum) in front
of the sensor. I know one of the Minolta Dimage cameras does, as I was
tasked with replacing this piece of glass (between sensor and Lens) with
one that would properly pass IR. A friend of mine was trying to get
into IR and thought this may be a good option. Turned out to be a pig
to do, and never properly worked (the replacement piece of glass caused
no end of focus issues).
So between the Sensor and the Lens is a lump of glass. Actually, on the
Minolta at least, it's a laminate of 4 pieces of glass. One is a blue
colour. The lump of glass seems to dramatically reduce the IR part of
the spectrum hitting the sensor.
The result of this was that by putting a filter (like an 72 mentioned
below) in front of the lens was that the R72 cut out the "visible" light
spectrum. The lump of glass between lens and sensor reduced the amount
of IR spectrum hitting the sensor. End result - VERY long exposures
required. Nice, but tripod and very still subjects required.
Removed the lump of glass, and the IR came through fine. Nothing would
focus properly, but IR was fine !
Not sure if this helps or not, but just a "beware" that not all Digi
Cameras are set up to do IR photography.
Regards,
Jon
-----Original Message-----
From: olympus-owner@xxxxxxxxxx [mailto:olympus-owner@xxxxxxxxxx] On
Behalf Of Wayne Culberson
Sent: 02 December 2005 16:31
To: olympus@xxxxxxxxxx
Subject: [OM] Re: hoya r72 questions
Well, what I was planning was to try infrared-type photogrpahy with the
digital cameras. I haven't really heard of your suggestion, but am
wondering
how the exposed film would work, as it has to be big enough to cover the
lens. So I'm guessing it has to be Medium format or larger film, then
fitted
somehow (light tight) to an empty filter? Sounds interesting. Any
further
instructions, or website you can point to?
Wayne
==============================================
List usage info: http://www.zuikoholic.com
List nannies: olympusadmin@xxxxxxxxxx
==============================================
|