Re: [APML] Equivalent ISO of an ST10E CCD

["Richard Kellogg" <rkellog1@twcny.rr.com>]

Jerry,

It depends on what signal to noise ratio you are willing to take.  Just as
you can push process film and operate at a higher iso, you can use a higher
gain setting on the A/D and get a higher number of counts for the same
amount of light.

I have a profesional 3-chip color TV camera, and I just checked it.  I got
the equivalent of ASA 500 for it at normal gain.  The gain can be increased
up to a factor of 8, or the equivalent of 3 stops, at the cost of much
increased noise.

If you look at the profesional digital SLRs from Nikon, you will see that
they have user selectable ISO settings from  200-1600.

Rick Kellogg




----- Original Message -----
From: "Jerry Lodriguss" <jml@astropix.com>
To: <astro-photo@seds.org>
Sent: Friday, April 05, 2002 11:39 PM
Subject: [APML] Equivalent ISO of an ST10E CCD


> Ok, here we go again.
>
> It seems like a simple question:
>
> What is the equivalent ISO of an ST10E CCD camera.
>
> If it is not, in fact, a simple question, please formulate a simple answer
> to explain it. <G>
>
> If I hook up an ST10E to a camera lens and take an exposure of a gray card
> in the sunshine, what exposure would I need in terms of exposure length at
> a given f/stop or correctly record the gray card?
>
> Simple, see? <G>
>
> Jerry
> Photoshop for Astrophotography Book:
> http://www.astropix.com/APBOOK/0_PROMO/PROMO.HTM
>
> Astrophotography, Tips and Techniques
> for Digital Enhancement in Photoshop:
> http://www.astropix.com
>
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