My trusty Canon 300D has started overexposing pretty much every shot (whites are too white and colours are lacking – is that overexposing?)
I use it mainly with a 70-200 L lens. I have very little idea about cameras, is the problem likely to be with the camera or the lens?
If it’s the camera is there a way to reset it to factory defaults just in case I’ve accidentally changed something?

Sure you haven’t adjusted the exposure compensation? Make sure the little arrow is on zero in display and not scrolled all the way to +3 or whatever the 300D goes to :o)

Stick it in auto. Does it still do it? If not, then you have moved something…probably exposure compensation.

Put back to whatever mode you had it in before trying it in auto. There will be a button somewhere with a +/- sign. Press that and it should display the level of compensation. 0.0 is no compensation and anything +ve will be over-exposing. While holding the +/- button, twiddle the command dial to get it back to 0.0
Sorry for the woolly explanation, but I am not familiar with Canon button presses, using a Nikon myself.

You can also check exposure compensation through the viewfinder with the shutter half pressed. There will be a bar indicator with a + at one end and – at the other.

reset it to factory defaults

generally, yes, on my nikons there are two of the function buttons marked with dots, press ’em both, hold for a few secs et-voila – presume canon are similar in some way?

Check it with another lens to be sure it’s not the aperture blades sticking on your favourite lens.

Metering – have you inadvertently set it off anything but your standard choice (normally ‘matrix’) metering?

Otherwise – as above – check exposure compensation has not been nudged….

Sure you haven’t adjusted the exposure compensation? Make sure the little arrow is on zero in display and not scrolled all the way to +3 or whatever the 300D goes to :o)

Hmmm, no that’s set to zero. I’ll keep playing.

Just had a look at my 40D and to reset, you go to tools (spanner) > “Camera user setting”, “Clear all camera settings”.

I remember once reading about a ‘hard’ reset by removing the battery and a smaller battery inside the battery bay, then turning it on, but I would contact Canon before doing that personally.

On Nikons you can set the area that is used for auto Exposure from whole view, progressively down to just centre spot. Useful for correctly exposing a subject when you don’t care / can’t control the background. But, can mess up things if you forget you’ve set it!

Ahhh, found the reset command – will if it’s any better

Post an affected image online, so we can read the EXIF data.

Did you try it in auto?

If you have a dof preview button, press it while looking down the lens will let you see if the aperture blades are moving.

Another thought was depending on where you are taking the pics, if you have the ISO set very high, the camera might be setting the smallest aperture it can but still getting over exposure. Would have to be strong sunlight though I would imagine, rather than in a living room…

Did you get to the bottom of this?

Just had a thought: maybe the contacts between the lens and camera are dirty?