Is it me or my camera?

Question

Seems anything taken at 1/1000 sec shutter priority is too dark; at full telephoto of 29mm Digital focal length). Fuji E900.
Shots that are OK are 1/500 sec, f/4, 12mm focal, ISO 80, also good 1/250, f/5.6 29MM
ISO 80.
But shots at 1/1000, f/5.6 29mm, ISO 80 too dark. I either have to lower shutter speed or not use focal length at 29mm to get proper exposure. No warning in viewfinder showing shot will be dark.
So is it me or should camera be serviced? These shots taken in bright sunlight.

Answer 1

If your shot is okay at 1/500 at f/4, then to use 1/1000 shutter speed, you'd need f/2.8.

If you shoot at f/5.6 at 1/1000, you're 2 stops underexposed.

So...it's you.

The camera at 29mm has a maximum aperture of f/5.6. There's no way to get f/2.8 at the full zoom. So you'll have to increase your ISO.

Using the sunny 16 rule, at ISO 80, you should be at 1/80 at f/16. Adjusting for each aperture, correct exposures should be:
1/80 f/16
1/125 f/11
1/250 f/8
1/500 f/5.6
1/1000 f/4

Your exposures are right in the ballpark:
1/250 f/5.6
1/500 f/4
and it should be 1/1000 f/2.8, but you're shooting at 1/1000 f/5.6.

So, it's you, plus the limitations of your camera.

Answer 2

The proper full daylight exposure at ISO 80 with a shutter speed of 1/1000 would give an aperture of about 5.3, or 1/3 stop less than the actual exposure you stated.

In any case, though, you state that in your situation, shots look okay at ISO 80, f4, and 1/500. When going up to 1/1000, and keeping the ISO the same, you should be opening the aperture up to f2.8, and not closing down a stop to f5.6.

I think the problem may be that at your longest focal length, the lens doesn't have a large enough maximum aperture to give the proper exposure. The only real solution to this would be to up the ISO.

Answer 3

Correct exposure is a result of the interaction of light, ISO, aperture and shutter speed.

Lets look at a hypothetical example at ISO 100, in bright daylight, using a fixed focal length 100mm lens.

At f2.8, 1/1000 sec.
At f4, 1/500 sec.
At f5.6, 1/250 sec.
At f8, 1/125 sec.
At f11, 1/60 sec.
At f16, 1/30 sec.

All 6 exposures will be IDENTICAL. You will notice an improvement in image quality as you stop down and an increase of Depth of Field (DOF) but the exposures will be identical.

One must remember, however, that a zoom lens at, say, f11 and at its longest focal length will likely transmit less light than a comparable fixed focal length lens at f11.

IMO your camera may need to be serviced.