Re: Metering for IR

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

On  8 Sep 96 at 18:43, John Gateley wrote:

> My last response made me think of this.
> The reflected light attachment on my Minolta Auto-Meter IVF is merely a
> disc with a hole in the center.
> Could a piece of filter gel be inserted in this to make the meter more
> sensitive to IR?

Yep, I have been pondering about the same for my Gossen Sixtomat 
Digital, since it has a sliding dome, and it has room for another 
sliding filter.

> If so, which filter would be best?

Tricky....I have noticed that my Gossen is rather consistent when I 
dial in 400ASA and use various IR filters, it corrects the +3 for red, +4 
for 87 and +5 for 87C rather neatly. The question is: what do you 
intend to use, and what do you want to meter for? IR-only, or a combo of 
IR+visible? 
All this is also largely depending on the IR sensitivity of your light 
sensor; if it blocks above a certain wavelength, you get a large 
error with the dark filters. Just check whether your most used filter 
give a proper reading, correct ASA if not, and see if is consistent 
for other filters.

--
Bye,

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The difference 
between men and boys
is the price of their toys

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

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Topic No. 11