Re: [APML] Equivalent ISO of an ST10E CCD

["Mike Connors" <micon@starband.net>]

Jerry,

No reply to your question here.  A couple of my own questions, however.
The gray card is 18% reflectance, yes?   Wouldn't that translate to 46 on a
scale of
0 to 255, as opposed to 128?  As  measured by densitometer, what density on
the negative or slide equals 128 on the above-mentioned scale?  If the gray
card is 18%, and you properly expose for that, then 100% (blank white, I
assume) is only 2.5 stops more exposure.  Does this match your results?
i.e., If you overexpose a negative by 3 stops while shooting a gray card, do
you get a solar filter ?.  BTW, all I know about CCD is how to spell it :)

Confused as well,

Mike Connors




Jerry Lodriguss wrote:

>If I put a gray card in the sun and I know the film speed and f/ratio, I
>can tell you exactly how long the exposure would be to put the spike in the
>histogram at level 128.


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