1-DX Overexposure when using continuous shooting modes with slow shutter speeds

My guess is this is a 'user error' rather than a camera issue
I recently acquired a second hand Canon 1-dx

If I take a single shot with a high or low shutter speed the exposure of the image is perfect.
If I use the high speed continuous shooting, or low speed continuous shooting, with shutter speeds of around 1/1000 then exposures are perfect.
If I use either of the continuous shooting modes with shutter speeds of around 1/100 then all the exposures are significantly over exposed.
I have tried all combinations of metering modes, exposure modes (manual v AV etc) and nothing seems to change the behaviour.
Any help greatly appreciated.

 

Is the aperture in the lens actually working, with the camera turned on and the smallest aperture selected (f22 or 32) look into the front of the lens and press the DOF button, you should see the aperture close down, try this at all aperture settings. If it is a zoom lens then try the same at various levels of zoom. If the aperture mechanism is sluggish then it may not be closing fast enough to operate in repeating operations.

 

Hi, thanks for the response. I think its the lens/aperture. Using the DOF button it was clear that it looked like it was not closing all the way intermittently. I then tried the lens on a friends camera and got the same results using the DOF button and when using the continuous shooting modes (perfect results wide open but overexposed when at F22). I use the smallest aperture and continuous shooting modes for pan/motion blur on various sports so I will experiment with the lens and various settings to see how far I can close the aperture before it starts to 'stick'. Thanks again.

 

It sounds like the camera may be using a faster shutter speed than intended in the continuous shooting mode with slow shutter speeds, resulting in overexposure. Here are a few suggestions to try:

1. Check the shutter speed settings: Make sure that the shutter speed is set to the desired value in both the single shot and continuous shooting modes. It's possible that the camera is defaulting to a faster shutter speed in the continuous shooting mode.
   
   
2. Adjust the exposure compensation: If the overexposure is consistent across different metering modes, try dialing in some negative exposure compensation to reduce the exposure in the continuous shooting mode with slow shutter speeds.
   
   
3. Check the auto ISO settings: If the camera is set to auto ISO, it's possible that it's selecting a higher ISO in the continuous shooting mode with slow shutter speeds, which could cause overexposure. Try manually setting the ISO to a lower value in the continuous shooting mode.
   
   
4. Contact Canon support: If none of the above solutions work, it's possible that there may be a technical issue with the camera. Contacting Canon support may be necessary to resolve the problem.

I hope it helps!