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Long exposure times (was:Re: [OM] OM4Ti meter)

Subject: Long exposure times (was:Re: [OM] OM4Ti meter)
From: Soenke Jansen <SoJa@xxxxxxxxxxxxxx>
Date: Fri, 03 Jul 1998 11:14:49 +0200
Chris Barker wrote:

> Franz Pangerl, in his book "The World of OM Systems" reckons that it is 
> because of
> the Silicon Blue Cells which do the measuring for OTF exposures (in the OM2 at
> least).  He reckons:...if the silicon photodiodes only receive weak measuring
> currents [in low light exposures], then they react with successively extended
> exposure.  This produces an unintentional but useful side-effect - a partial
> balance of the reciprocity law failure."
> 
> NB my square brackets.
> 
> Chris

Oops!
Thanks Chris. But in a way this is nasty too (not your citation of
course, but the SBCs overreacting). Because that means, if I follow the
tables and graphs, the film producers give for
'reciprocity-failure-compensation' I'll overcompensate. And bracketing a
4min exposure takes you to something like a quarter hour you spend with
that motive in which time the light situation will have changed for
sure. Any solution in sight?
Dumbfundled,
Soenke, Hamburg

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