Archived posting to the Leica Users Group, 2004/09/06

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Subject: [Leica] Re: MORE THAN... R.I.P. ILFORD
From: bladman99 at (Dan C)
Date: Mon Sep 6 11:32:28 2004
References: <002901c49426$dc369810$f48a3d42@home> <> <> <002901c49426$dc369810$f48a3d42@home>

Depends on the camera.   My Minolta Dimage 7 was very sensitive to IR
radiation; all I needed was an 89B equivalent filter, set the camera's ISO
to 400, and I was able to take hand held shots in daylight, and get a
preview in the electronic viewfinder of how the shot would look.

Minolta added IR blocking filters to later incarnations of the camera,
making IR photography much more difficult (the IR sensitivity of the camera
effected regular photography in some circumstances).  I suspect most
companies are doing something similar.

-dan c.

At 11:18 AM 06-09-04 -0700, Adam Bridge wrote:
>I think I posted a link to info about how to use a digital was an IR
>camera. You need to heavily filter to cut out most of the visible
>light and leave only a little red plus the IR. You get an ASA of like
>1 or 5 or something. LONG exposures.
>Ah - here's a site although it doesn't look like the site i posted:
>On Mon, 6 Sep 2004 11:33:29 -0400, Dan Post <> wrote:
>> Other Dan-
>> I agree with you- the de-colorization of a digital image is great for
>> generating B&W! I played around with my Leica Digilux Zoom (spent all my
>> ducats on an M7 so I have to wait a while for the 'biggie'digital!) and
>> found that by eliminating all but the red channel- that I had a nearly IR
>> photo. I imagine it was pretty close as the CCD is sensitive to IR in
that I
>> looked at the IR LED on the VCR flinker, and the otherwise invisible beam
>> shows up as a pale blue in the Digilux viewfinder.
>> I would be interested to know what the full spectral response might be as
>> the IR effect of shooting and keeping only the red information works 
>> pretty
>> well.
>> I did try shooting through a Leitz IR filter (looked about the equivaent 
>> of
>> an 87C- very deep red- and of course got zip, zilch, nada for my effort.
>> If the future is digital, think of the possibilities of shooting in the UV
>> and Near UV spectrum, and taking IR photos as a regular course--- I am
>> pretty sure that folks like astronomers already do this with the CCD
>> they use- The Three College Observatory near here has published some 
>> really
>> neat timed exposures (5 minutes!- sharp with no camera shake!) of deep
>> objects outside the visible spectrum. I guess they are 'false' color, but
>> they are simply beautiful. I can see why amateur astronomy is so popular!
>> Dan(Wistfully thinking about what Santa might bring...)Post
>Leica Users Group.
>See for more information

In reply to: Message from dpost at (Dan Post) ([Leica] Re: MORE THAN... R.I.P. ILFORD)
Message from bladman99 at (Dan C) ([Leica] Re: MORE THAN... R.I.P. ILFORD)
Message from abridge at (Adam Bridge) ([Leica] Re: MORE THAN... R.I.P. ILFORD)