[Leica] IR filters

[henningw at archiphoto.com (Henning Wulff)]

At 1:03 PM -0600 2/6/07, Lottermoser George wrote:
>Thanks Henning and Leonard. I guess this about as much as I can 
>expect. The real learning comes from use of one of them and 
>determining if I want more less cut off of the visible spectrum. 
>That about right?
>
>Regards,
>George Lottermoser
>george@imagist.com
>
>
>
>On Feb 6, 2007, at 12:58 PM, Henning Wulff wrote:
>
>>Or, if you are ordering Heliopan filters anyway, order a #5715 
>>which is an 88A equivalent, which cuts out more of the visible than 
>>the 89B and lets in more shorter wavelegths than the 87. This would 
>>be the ideal filter for most IR photography, as it allows shorter 
>>exposures than the 87 but still allows a stronger IR effect in most 
>>ways equivalent to the 87.

George, i've got pretty much the whole range in 3x3 gels from Kodak 
from a long time ago, so I can try out various ones and see which I 
like best. I also have a Leica IR filter which is 89B equivalent, and 
093 and 092 B+W from a while ago.

I'll probably get a Heliopan 5715 for the lenses I'll use most for 
IR. The APO Aspheric lenses are best for IR, but are not the right 
focal length for what I want to do most which is wideangle. So a 55mm 
filter for the 21 with step down rings should be about right. I still 
have a snap on gel filter holder for careful use on all other lenses, 
including the 15 and 12.

The newer aspheric lenses are a lot better for IR than earlier 
designs, as they are better colour corrected and will give sharper 
results in IR as well. Some older lenses will give quite soft results 
in IR even at optimum apertures. The VC lenses tend to be better than 
50's Leica lenses, but not as good as current Leica offereings. 
Pretty much the same results as in the visible spectrum.

If you want to try stuff, get this holder:

http://tinyurl.com/2ameea

after rooting around camera shops for old drawers full of (older) gel 
filters. You can still pick up various Kodak gels for $5 each with a 
bit of patience.

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