Re: Infrared lenses

["Willem-Jan Markerink" <w.j.markerink@xxxxx>]

On 24 Jan 97 at 20:00, RUBEM GUIMARAES AMARAL wrote:

> 
> I'm sorry if this matter has already been discussed here, but did 
> any of you ever tried using infrared lenses? When I went to the
> US last year I noticed that they were being sold in almost every
> photo stores. Do they produce the same effects of IR films?

Mmm....could you be more specific? 
Are you talking about night vision scopes? Aka infrared scopes?
They do see *also* into the infrared spectrum, but as with infrared 
film, you need an dark (opaque) infrared filter to block out the 
visible part of the spectrum. But once you mount such a filter in 
front of the scope, you indeed get the same unworldly effect as with 
HIE.

Actually, I even use such a small night vision scope to provide some
kind of IR-assessment tool before I take pictures, since this is the
only way to get 'real time' vision (videocam(corder)'s, especially
b&w ones, will do the same btw). 
A cheap one too (1st Gen, not like modern 2nd or 3rd Gen), since it
is not particularly good to use these things in broad daylight;
luckily mine uses a M42 photo lens with diaphragm, and with both dark 
IR filter and closing down I dim the light sufficiently.

Check my homepage for a story on how I discovered this trick:
http://www.a1.nl/phomepag/markerink/mainpage.htm

--
Bye,

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      The desire to understand 
is sometimes far less intelligent than
     the inability to understand


<w.j.markerink@xxxxx>
[note: 'a-one' & 'en-el'!]

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