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A couple of oddities that I've found with the Nikon D50:

Exposure: On the manual settings when taking multiple pictures (same scene,
same light conditions) the resulting images come out with different
brightnesses, even though the settings are the same, and the exif record the
same expsoure values...

Infrared: Although the D50 is pretty good at infrared exposures, the
'standard' 18-55 lens doesn't seem to be able to focus infrared very well -
even when manually focussed just off infinity and well stopped down. My
manual 50mm or 24mm lenses produce very nice, sharp IR images.


Chris

"CHRIS KIDD" <> wrote in message
newsfrDg.20793$...
.. . .
>
> Infrared: Although the D50 is pretty good at infrared exposures, the
> 'standard' 18-55 lens doesn't seem to be able to focus infrared very
> well - even when manually focussed just off infinity and well stopped
> down. My manual 50mm or 24mm lenses produce very nice, sharp IR images.

It's possible that lens just won't focus those wavelengths well no matter
what you do. Infrared doesn't seem to be something that makers of lenses for
digital cameras are much interested in accommodating. I notice that neither
my Nikon 18-70 DX nor 10.5mm DX has an IR focusing mark.

Neil

"CHRIS KIDD" <> wrote in message
newsfrDg.20793$...
>A couple of oddities that I've found with the Nikon D50:
>
> Exposure: On the manual settings when taking multiple pictures (same
> scene, same light conditions) the resulting images come out with different
> brightnesses, even though the settings are the same, and the exif record
> the same expsoure values...
>
>
> Chris
>
Sound as if the Shutter is inconsistent. Most shutters are, and always have
been, but the variations are usually small enough not to produce visible
differences in exposure.

They only used to show up on Shutter Speed / Exposure Testers, which every
Camera Repairer used on Film Cameras. Anything within + or - 10% was
accepted as being accurate. Most places would run tests and produce a print
out for a modest fee. I do not know how it is done nowadays, because there
is now no way of putting the detector in behind the lens (and mirror of an
SLR).

Roy G

CHRIS KIDD wrote:

> A couple of oddities that I've found with the Nikon D50:
>
> Exposure: On the manual settings when taking multiple pictures (same scene,
> same light conditions) the resulting images come out with different
> brightnesses, even though the settings are the same, and the exif record the
> same expsoure values...

What are the conditions ?

Off the top of my head:

Outdoors, if it's cloudy, the light can vary slightly as the
clouds move across the sun. (Even if they appear even to the eye)

Indoors, if you have incandescent or florescent lights and you're
using less than 1/60 second exposure, you can get variations because
these types of lights actually flicker very rapidly.

CHRIS KIDD wrote:
> A couple of oddities that I've found with the Nikon D50:
>
> Exposure: On the manual settings when taking multiple pictures (same scene,
> same light conditions) the resulting images come out with different
> brightnesses, even though the settings are the same, and the exif record the
> same expsoure values...
>
> Infrared: Although the D50 is pretty good at infrared exposures, the
> 'standard' 18-55 lens doesn't seem to be able to focus infrared very well -
> even when manually focussed just off infinity and well stopped down. My
> manual 50mm or 24mm lenses produce very nice, sharp IR images.
>
>
> Chris

Were you shooting jpeg or RAW. The jpeg compression includes a
brightness normalization based on the scene content. So even if the
lighting is held constant, the arrangement of stuff in a scene CAN
influence that normalization. This is true of any camera shooting
jpeg. So if the scene is truly identical something else may be in play
here, but if it is the same BASIC scene, but different people with
different clothing, etc,, that could be the jpeg normalization.

CHRIS KIDD wrote:

>A couple of oddities that I've found with the Nikon D50:
>
>Exposure: On the manual settings when taking multiple pictures (same scene,
>same light conditions) the resulting images come out with different
>brightnesses, even though the settings are the same, and the exif record the
>same expsoure values...

If you're using the default settings, I believe the sharpness and
contrast are set to Auto, and that can have an effect shot-to-shot if
the camera decides to use a different setting. I presume the ISO is the
same in each shot and not set to Auto either.

Try using specific contrast and sharpness settings and see if that fixes
the issue.

>Infrared: Although the D50 is pretty good at infrared exposures, the
>'standard' 18-55 lens doesn't seem to be able to focus infrared very well -
>even when manually focussed just off infinity and well stopped down. My
>manual 50mm or 24mm lenses produce very nice, sharp IR images.

The coatings on the lense can affect certain frequencies and actually
filter them to some extent. The 18-55 probably doesn't pass IR that
well.