david_marat

Ok, this is what I found on the Canon CP-E4 battery pack's manual at retail store:

"When using an EOS DIGITAL camera with the Compact Battery Pack CP-E4, images may contain noise due to electromagnetic interference. Therefore, be sure to keep the battery pack at least 5 cm/2 inches away from the camera body. Also, do not directly attach the Compact Battery Pack CP-E4 to the tripod socket on an EOS DIGITAL camera other than as EOS-1D series camera. When using an EOS DIGITAL camera other than as EOS-1D series Camera, attach an optional battery grip to the camera's tripod socket, then attach the Compact Battery Pack CP-E4 to the tripod socket on the battery grip."

Well, I new that a distance between a camera body and the batery pack matters swomehow and now it is clear somehow. That's why I mentioned about a battery grip - increasing the distance. Anyway, this is just theory. I wander how it works in the field.

David

As I remember the original source was the battery pack's manual.

David

I found some info stating that when using Canon Battery Pack attached directly

to EOS DIGITAL camera, images may contain noise due to electromagnetic

interference. May a battery grip (on 40D) resolve the problem? Any experience?

Thanks,

David