By using the lens twist method or the nikon lenses (with adapter) you can force the ISO to remain at 200 enabling faster shutter speed.

Testing with a 50-mm 1.4 lens using the twist method I could normally achieve 1/200 shutter speed at ISO 100 in the light of my kitchen.

After enabling 'Highlight Tone Priority' the camera is forced to use the lowest ISO of 200 thus enabling a faster shutter speed of 1/400 in the same lighting conditions.

The same would apply using a nikon fit lens.

The test yields no difference under normal camera operations with the canon lens fully attached.

James

You are the man. You also have a bright kitchen.

The question is: Will Canon EVER give you a repair under warranty.

Next: Exposing the 5DII to gamma radiation for extended battery life. :)

Hi Don,
It's true I do have a bright kitchen but I didn't say it way a bright picture.

I did point the camera up at the heavens last night using a very long exposure trying to capture some cosmic rays. Not sure it helped the battery life :) in the end I just made light trail pictures with the moon in an effort to make a Christmas tree shape in the night sky.

I do fiddle with this camera alot, trying to find some way to get it to do what I want. Now if I could just do the same with the wife!

James