ttl metering

Does anyone check the accuracy of the metering system in their camera?
Is it accurate through every ISO speed. Just curious.
eric phillips

Nope, haven't checked...but if it isn't ...what do you think you can do
about it? Adjust it for every shot? Just take the photo and it will be close
enough in almost every case...close enough to adjust in your editing
program.

"eric phillips" wrote in message
...
Does anyone check the accuracy of the metering system in their camera?
Is it accurate through every ISO speed. Just curious.
eric phillips

On Sun, 06 Mar 2005 21:14:11 +0000, eric phillips wrote:

Does anyone check the accuracy of the metering system in their camera?
Is it accurate through every ISO speed. Just curious. eric phillips

Check against what ? Whether a picture is slightly over or underexposed is
in the eye of the beholder.

I compared D-Rebel against EOS300 using the same lens - Sigma 28-300. At
the same ISO (100 - 400) both gave the same exposure throughout. However,
at ISO 800 EOS300 consistently gave half a stop over the D-Rebel in
various shutter speed - aperture combination. I took some pictures with
D-Rebel in that setting and they looked OK. I did not take any pictures
with EOS300 alongside D-Rebel for direct comparison. I never had any
problem of underexposure with EOS300 & that Sigma lens, though I have
never used a 800 ISO film. From this crude test I can say D-Rebel & EOS300
has very similar exposure system (no surprise, eh :-)) and to my eyes they
are "accurate".

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Gautam Majumdar

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On Mon, 07 Mar 2005 05:41:43 GMT, "Gene Palmiter"
wrote:

Nope, haven't checked...but if it isn't ...what do you think you can do
about it? Adjust it for every shot? Just take the photo and it will be close
enough in almost every case...close enough to adjust in your editing
program.

"eric phillips" wrote in message
.. .
Does anyone check the accuracy of the metering system in their camera?
Is it accurate through every ISO speed. Just curious.
eric phillips

Well You could check it out by the method of trial and error.
You have to have a sunny day to try this.
The old days there was the 'Sunny f/16 rule where the correct exposure
at f/16 would correspond to the ISO number. I.E. 100 = f/16 at 1/90.
ISO 200 = f/16 at 1/180 .400 = f/16 at 1/500.
Set the camera to manual ISO 100 f/16 at 1/90 set the lens to
infinity aim at a portion of a tree trunk that is in full light and
half depress the shutter and the pointer should be centred.
Repeat this in every ISO and any anomolies will show up . Make a note
of these and you should know exactly what settings to set up before
shooting.
eric phillips

"eric phillips" wrote in message
...
Does anyone check the accuracy of the metering system in their camera?
Is it accurate through every ISO speed. Just curious.
eric phillips
Yes, every year or so I check to see that the metering system in all of my
cameras is still giving correct results (according to the sunny 16 rule).

Yes, they are all accurate enough.

My cameras are 2 F3s, an N90S, and a D70. The film cameras have been placed
on leave...

Jim

eric phillips wrote:

Does anyone check the accuracy of the metering system in their camera?
Is it accurate through every ISO speed. Just curious.
eric phillips

The only tests I do, very occasionally:

I

Set up a grey card under difuse light.
Meter it (spot preferably) with the lens axis perpendicular to the card.

Incident meter it (with an incident meter) dome pointing where camera
reading was taken.
Should be within 1/3 of a stop.

II
...very bright cloudless day.
...two hours before, or two hours after solar noon.

...Set ISO to 100
...Set aperture to f/16
...Put a white styrofoam coffee cup (clean, preferably) over the lens
...point at the horizon in the direction of the sun.

Should read a shutter speed of 1/100. Acceptable would be 1/90 to 1/125.

III

If I have a few frames of slide film left to go, and I have nothing
better to do, I shoot the frames at various apertures under a studio
strobe using the meter to set for, eg, f/5.6. Then I shoot that and the
apertures in 1/3 or 2/3 stops on each side of f/5.6 (steps according to
the number of frames left. The target is something colorful plus a grey
card). Note the frame numbers and settings. When I get the frames
back, it is pretty clear which is the right exposure and compare to the
notes.

Cheers,
Alan.

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