There is no easy answer to your question.
The megapixels have more to do with printing than with viewing on a screen.
And you have to be sure that you are comparing apples and apples.
You have to be comparing the exact same scene.
You have to be using the exact same shutter speed, aperture, ISO setting and zoom setting
Both cameras have a very sharp lens.
The A400 has less Megapixels and less pixel density, which lets it put larger pixel elements on each CCD sensor.
That reduces the noise generated by an overcrowded CCD sensor assembly.
The A400 is limited to ISO 400 while the SX10 lets the camera select as far as ISO 1600.
Take a picture with the A400, then write down the shutter speed, aperture setting, ISO setting and zoom setting.
Take the SX10IS and use the Aperture Priority setting with the aperture set to the same setting, the ISO setting the same and zoom setting the same. The SX10IS will then select the correct shutter speed for a good exposure.
Now take the identical scene with the SX10IS.
Then you can compare apples to apples.
Hi...i'm trying out the Canon Powershot SX10 IS (I got a great deal on it) and trying to compare it to my much beloved Canon Powershot A400. In my initial trials the photo quality of the SX10 (with 10 megapixels) seems softer than that of my A400 (with 3.3 megapixels). That being said, is it possible that the A400 can have better overall photo quality than the SX10 despite only having a lower resolution?