Canon A510 - exposure metering bug
(deutsche Variante)

There is a bug in the exposure metering system of the A510. The A520 (nearly the same like the A510) probably contains the same bug. This page should document the bug and show how to work around. Until now no test of the A510 contains some information about that bug, at least I haven't read something about it.  

content:
1. fault description
2. some example pictures
3. how to work
around

 1. fault description
The fault occurs if you swivel the camera from a dark scene to a bright one and then press the shutter button to make a picture.
First you point with the camera to the dark scene about 4 seconds. You can take a picture of the dark scene, if you want.
Now you swivel the camera fast to the bright scene. Immediately after finished the swiveling (NOT during you swivel), you press the shutter button half way down. Now the camera measures the exposure and try's to get a correct focus point. After it displays the Ok for the focus and the exposure data, you press the button full way down. Normally you get overexposed image.
Now you wait 2 seconds (the camera still points at the same bright scene) and take another picture. The second one is normally correct exposed.

Here the answers to the most asked questions:
- If you press the shutter full way down and take an picture or if you first press the shutter half way down and after measuring full way down doesn't make a difference.
- there is no difference if you swivel to the bright scene and wait or if you make a picture and wait. After a little break (2 to 3 seconds) the picture is fine.
- I don't press the shutter button during I swivel the camera. I pressed it after.
- I doesn't use the self timer-mode
- it occurs in P, A, S and M-Mode
- The bug is reproduce able. In daily use it's not so strong like in this example, but I often get overexposed images (even with EV-Compensation to -0.3 or -0.7)
- If the A510 needs more time for measuring the right exposure, why it doesn't take that time and do a correct job?
- There is no big difference between the exposure measure methods (Evaluative, Center Weight Average, Spot).

 2. Some example pictures

Olympus C-4040 - P-Mode Canon A510 - P-Mode
the dark scene:

f1.8, 1/13 ISO100

 

f2.6, 1/10 sec, ISO100

 

 

bright scene direct after swivel:

f3.6 , 1/800 sec, ISO100

 

f4, 1/200 sec, ISO100

bright scene after 1. picture and break:

f4.0, 1/650sec, ISO100

 

f4.0, 1/500 sec, ISO100

Both cameras always have some different opinion about right exposure. The Canon always produce a bit brighter images than the Olympus. This is a question about personal preference, you can correct this with the exposure compensation if you want to.
Don't take care about the white balance. The Olympus was set manual for my preferred outdoor shooting colours, the Canon was set to Auto.

 The Olympus also changes the exposure if you give her a little big thinking time. But, whether it use f3.6 and 1/800 sec or f4.0 and 1/640 sec is not important, both settings capture the same and right amount of light. The Canon produces different images, the first is very overexposed. Now some 1:1 crops to show this clearly, you lose much highlight-detail. The two pictures from the Olympus are nearly the same, so I just show one example.

Olympus C-4040 Canon A510
bright scene after break:

f3.6, 1/800 sec, ISO100

 

f4.0, 1/200 sec, ISO100

bright scene after swivel:

f4.0, 1/650 sec, ISO100

 

f4.0, 1/500 sec, ISO100

   

The second image of the Canon is in my opinion also a bit to bright, but it's the Canon look, If you don't like it, use the EV-Compensation with -0.3 EV and you will have no problem. In both cameras the sharpening was set to soft (by the canon via "low sharpening effect", -1 at the C-4040). If you don't do this, the loss of high-light detail would be even more dramatic.

 3. How to work around?
There are two ways to work around:
- wait 2 Seconds before you take the picture while pointing at the scene you want to capture (for composing pictures and not moving subjects)
- disable the live preview on the LCD of the A510, use the viewfinder

The second way clearly shows than Canon can take correct measures. Why not with Live-Preview on the LCD? But there is also a problem with the second method. If you disable the live preview on the LCD Display you also switch off the manual focus. So you get a higher shutter delay. I think, it isn't necessary, you have huge depth of field if you stay at the wider end of the zoom.

Foveon