Re: Pinhole Light Meter

Low light - yes very low. I made it to take photographs of sunsets and
sunrises. These last only a few minutes with very variable conditions.

I currently use it for f/138 but it can theoretically work with
f/anything. I have a spreadsheet of the necessary calculations for each
f/stop that are programmed into the microcontroller. You then select
from the available f/Stops via the rotary encoder.

It does not currently cater for reciprocity failure primarily because
the Provia F100 I use does not seem to have much. Being a film based
parameter that would necessitate, currently, under or over stating the
film speed you are using after taking a meter reading. Reprocity failure
compensation would actually not be hard to program I am just worried
that there may be hundreds of different papers / films people can use
all with different characteristics.

After hearing a few comments it seems wise to keep separate the shutter
and driver and the light meter components. With perhaps a small Pizo
buzzer when optimal exposure has been obtained. I suppose I just don't
like chance when I'm dealing with fleeting situations or carefully
arranged compositions.

All the best

John

----- Original Message -----
From: "Colin Talcroft" <ctalcroft@yahoo.com>
To: <pinhole-discussion@spitbite.org>
Sent: Saturday, August 05, 2006 3:48 AM
Subject: Re: [pinhole-discussion] Pinhole Light Meter

> Just to clarify, this meter would be capable of
> automatically metering low-light situations using very
> small (pinhole) apertures and also accounting for
> reciprocity failure? Maybe I misunderstood, but I'd
> love to have a meter capable of doing that even
> without the shutter.
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Received on Fri Aug 4 15:47:19 2006