Infrared digital photography

Archived from groups: rec.photo.digital (More info?)

rick white via PhotoKB.com wrote:
> Hi,
>
> I have an Olympus C-350 zoom. I m really keen to try for some infrared
> shots but can t yet afford to step up to SLR. Can anybody tell me if and
> how I can achieve some results with what I have???
>
> Richard
>
You can learn much on the IR topic by searching this group,
alt.photography and others. Briefly:
1) Assuming the C-350 is a digital camera, photograph the IR
light emitted by your TV remote to determine whether your
camera will capture IR.
2) Use a 72R (red) filter and photograph a scene with bright
sun high in the sky, lots of bright green foliage, some
white puffy clouds. Convert to gray scale.
3) Avoid the IR test and the filter by using the channel
mixer in Photoshop to create IR effects from color images.
--David

Archived from groups: rec.photo.digital (More info?)

David Ellis <blackhole@nospam.org> writes:
> rick white via PhotoKB.com wrote:

>> I have an Olympus C-350 zoom. I m really keen to try for some
>> infrared shots but can t yet afford to step up to SLR. Can anybody
>> tell me if and how I can achieve some results with what I have???

> Briefly:
> 1) Assuming the C-350 is a digital camera,

It is. (A 3.1 Mpx one from 2003).

> photograph the IR light emitted by your TV remote to determine
> whether your camera will capture IR.

I have yet to find a digital camera that "fail" the TV-remote-test.
ALL digicams can do IR (to some extent).

Unfortunately, it doesn't tell you how well suited the camera is for
IR photography. A Canon S50, for instance, will happily pass the
TV-remote-test, but the S50 pretty useless for digital infrared
photography. Its sensitivity to IR wavelengths is very low (about
1% of the Oly 2020Z's sensitivity) and it sports a lens design that
results in a horrible blurred hotspot in the middle of the image.

A much better test, without going to the expense of buying a
filter, is to shoot through an unexposed (black) piece of slide
35mm film. This is opaque to visible light but transparent in
the infrared part of the spectrum. If you have two polarizers,
stacking them and twisting them so that no visible light pass
through is another alternative makeship IR-pass filter.

> 2) Use a 72R (red) filter and photograph a scene with bright sun
> high in the sky, lots of bright green foliage, some white puffy
> clouds. Convert to gray scale.

The filter you need is R72 (Hoya), Wratten 89B (Kodak et al),
or RG715 (Heliopan). These are /not/ a red filters, but filters
that cuts visible light below 715/720 nm. A red filter
(Wratten 25) cuts wavelengths below 600 nm.

> 3) Avoid the IR test and the filter by using the channel mixer in
> Photoshop to create IR effects from color images.

That is not infrared photography.
--
- gisle hannemyr [ gisle{at}hannemyr.no - http://folk.uio.no/gisle/ ]
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Kodak DCS460, Canon Powershot G5, Olympus 2020Z
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