From: Alan Friedman <alan@greatarrow.com>

Date: March 24, 2008 3:29:52 PM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] IR filter with a DMK color .AS camera?

Hi Duane,

I believe the DMK cameras are all monochrome models without an IR cut filter. If you are using this camera with a color filter wheel for RGB imaging, it will be necessary to use filters with IR blocking or a separate IR block filter else the color will be skewed by the IR sensitivity of the chip. If you are imaging a monochrome subject (like the moon) in white light and have refractive optics in the system you will probably obtain sharper results by filtering out IR and UV wavelengths. 

If you are using a color camera (DFK, DMK) - I believe these do have an IR blocking filter before the chip - but I have never used one so I'm not certain.

best regards,

Alan

On Mar 24, 2008, at 5:04 PM, Duane wrote:

I'm pretty far along in this game to be asking about simple rules, but this one's got me
wondering...

I forget the exact model... but I've got a DMK Color camera with the .AS after it.

Do I need to use the IR filter on planets and the Moon?

I didn't think I needed to with color web cams (like the Fire-i) but I was wondering about the
.AS (I thought that was just a firmware change but not sure).

I've tried it both ways and didn't see much difference, but then again the nights I was out
didn't present me with the best skies.

In any case, easy question for those who know.

Thanks,

Duane