Weston/D70

Archived from groups: rec.photo.digital.slr-systems (More info?)

Bruce,
The issue is not so much whether the Nikon ISO values are 'correct'
as much as whether or not the Weston readings will give you exposures
that are appropriate to the way the Nikon 'sees' things. Meter
calibration is known to vary from manufacturer to manufacturer...ISO
values are a starting SUGGESTION and it is up to each manufacturer to
follow the formula in the ISO standard, but the ISO standard has a
Constant in the equation which the manufacturer choses to use! For
that reason, Sekonic meters might yield a different exposure than a
reading in the same light taken with a Minolta meter, yet both are used
by pros.
Add in the additional variable of what YOUR lens apertures really
behave like (optimistic, pessimistic aperture size in reality vs. the
indicated setting) and how your shutter behaves (slow, fast, right on)
in your camera! So run some tests and decide for yourself how well
matched you Weston readings vs. your actual results compare to your
expectations!

--Wilt

Archived from groups: rec.photo.digital.slr-systems (More info?)

Tony Polson <tp@nospam.com> wrote:

> "Bruce" <brucefalcon@blueyonder.co.uk> wrote:
>
>>Thanks for your advice regarding the AIS lens compatibility to the
>>D70.
>>
>>Next question relates to exposure. Because I tend to photograph
>>landscapes under extreme lighting conditions the D70 system usually
>>fails to get the exposure right, so I was thinking of using my old
>>Weston Master meter with the (at times ) the invercone. The question
>>is, Nikon quote an ISO/ASA rating of 200, can this be relied on or is
>>it an approximation.
>
>
> Why not try it and see?
>
> Set your Weston to an ISO/ASA rating of 200 and set the shutter speed
> and aperture combination to the exposure indicated by the exposure
> meter. Carefully examine the results, using the histogram feature and
> by examination of the resulting files in your image editing software.
>
> If you decide that the results are under- or over-exposed, adjust the
> ISO/ASA setting accordingly on the Weston.
>
> Job done!
>
>
>

Keep in mind that the light sensor cells in old Westons age badly and
many of them read 2 or 3 stops off after 25 years or so.