Re: [APML] Equivalent ISO of an ST10E CCD

[lkt <tan@cox.net>]

Jerry,

	Sorry I was not being very precise. I picked ASA 400 and 1600 only to
show that one is higher than the other. You are right, the speeds should
show 3 stops. Again, you are right about the gray only having one level.
Once again this is due to me not being very precise in answering your
question. The image of the gray card will fill every well in the CCD
exactly and equally up to say 4 bits if you expose for 8 secs. If you
expose for 1 sec, it will fill the wells less by 8X or 1 bit.

Loke



Jerry Lodriguss wrote:
> 
> Loke,
> 
> One second to eight seconds is three stops.  ISO 1600 to ISO 400 is two stops.
> 
> I don't get your example.
> 
> If you example is true, it's like saying I can underexpose the gray card by
> two stops on film, and that makes the film speed two stops faster, but then
> the middle gray is down in the toe of the film where it's noisier, and not
> middle gray anymore.
> 
> The gray card should have one level only, so how does the "light from the
> gray card now fills the 4-8 bottom bits of the well"?
> 
> Are you really telling me that NO ONE has ever hooked an ST-10E up to a
> camera lens and made exposures of a gray card in sunshine?
> 
> Jerry
>

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