Hi Joe,
Thanks for that input. Makes perfect sense and With my Hoya filters I
was seeing more effect visually than the camera was.
Where do you go to get these custom filters made?
Cheers,
Wayne
Wayne J. Cosshall
Publisher, The Digital ImageMaker, http://www.dimagemaker.com/
Blog http://www.digitalimagemakerworld.com/
Publisher, Experimental Digital Photography
http://www.experimentaldigitalphotography.com
Personal art site http://www.cosshall.com/
Joseph Miller wrote:
> Wayne J. Cosshall wrote:
>>
>>> "Wayne J. Cosshall" <wayne@[EMAIL PROTECTED]
> wrote in message
>>> news:46b4066b$0$30511$afc38c87@[EMAIL PROTECTED]
>>>
>>>> I've been experimenting with using a circular polarizing filter when
>>>> shooting digital infrared images:
>>>> http://www.dimagemaker.com/article.php?articleID=1053
>>>> Wayne
>>>
>
> A few remarks, FWTW. There are two different influences affecting the
> final results in your IR pictures. A circular polarizer consists of two
> filters: a linear polarizer followed by a quarter-wave retarder. Neither
> of these is fully achromatic, that is, they only have a limited
> wavelength range over which they are fully effective. Outside its range
> the linear polarizer will have decreasing effect in polarizing light,
> and outside its range the retarder will convert less of the lineraly
> polarized light to circular. Both tend to start failing rather badly as
> you go into the IR, so I would expect diminished affect by rotating the
> filter in the IR. How much depends on the specific polarizer and could
> change with maker.
>
> For my research I had achromatic polarizers and retarders fabricated
> that worked from the UV to the IR, but they were very expensive. Normal
> ones made for cameras start losing there effectiveness in the blue and
> the red, only working well in between.
>
> Joe
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