John Hermanson wrote:
>
> He's just about right. When you think about it, as the slit gets wider and
> wider, the cell sees less and less of the curtain and more of the film.
> The otf cells are active while the first curtain is moving so the circuit is
> always blending curtain and film reflectance .
> 1/60 would be the fastest speed where the film is totally exposed to the cell
> before the second curtain starts to move.
>
> John
>
Hi John,
I want to go a bit further here:
In auto mode.
- the mirror up and SBC check for shutter curtain reflection.
- if reading above 1/60s, computer fixed the shutter speed here.
- if reading below 1/60s, no value are set.
- when shutter is FULLY OPEN, another value from film reflection are
checked.
- film reflected light are accumulated and calculated by the computer,
when exposure is enough, computer send signal to close the second
curtain. (of course the computer should close the shutter a bit early to
take the curtain travelling speed into account.)
I think the computer will not perform any measurement during blending of
film and shutter curtain. The above is what I think only, it may be
wrong. But this seems a more logical design.
C.H.Ling
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