Re: infrared question -Reply -Reply

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

On 19 Oct 96 at 7:57, Walton wrote:

>      Thanks Tammy.  Using smaller apertures will help.  I was trying to
> remember your original post and was thinking you mentioned larger
> apertures.  Guess I was remembering wrong.
>      Over 20 years ago I was shooting Infrared Ektachrome without worrying
> about refocusing and the results were all sharp.

The problem is that you *can't* refocus with Ektachrome IR (EIR), even though 
the film is as IR-sensitive as HIE. The problem is that you record 
almost the entire visible spectrum as well, unlike HIE. A refocus for 
EIR would render the visible portion fuzzy....8-))
However, my German literature clearly states that for unavoidable 
wide open apertures (aerographics!) an APO lens design is a must to 
improve image quality.

 
--
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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Topic No. 4