I couldn't wait for Christmas

[Joel Eade]

I bought FoCal, since I thought it would be a good time to because I had to check out the new 24-70mm.
I just ran the new lens through three sets of tests. In all about 12-15 cycles at each length and I repeated the test three times.
Tests had the same lighting, right at EV 11 with around 1/350 shutter speed.

With the 1D IV I have the following results;
24mm 0
35mm +4
50mm +4
70mm -1
I could discount the 24mm as it dropping off will not hurt much. The drop from 50mm to 70mm with a difference of 5 bothers me.
I think I will ship it back and try another copy.
Any one think the camera could be a problem?
The 5D II had similar results only not as exaggerated. It makes me think the 1D IV AF tunes to a finer edge than the 5D II.

Does it have a visible effect on the images? That doesn't sound like a camera problem to me and it may fall within the factory specs for the lens especially considering the 24mm and 70mm are so close. It might be worth trying another copy but if the images are good I would not send it back.

[HDNitehawk]

Does it have a visible effect on the images? That doesn't sound like a camera problem to me and it may fall within the factory specs for the lens especially considering the 24mm and 70mm are so close. It might be worth trying another copy but if the images are good I would not send it back.

That is what I have been debating. It feels prime sharp, but I didn't get a chance to set it up on controlled test for sharpness yet. I was able to shoot several hundred shots Saturday morning and was fairly impressed. The lens seems very sharp, but I did notice that some of the shots were a bit weak. I should go back and see if they were primarly in the mid range. Maybe do some more testing, it wouldn't matter if I send it back today or tomorrow it would still be next week before I get a new one back.