24-70 F4 IS Owners...Test This Please!

So, I got my lens from Adorama...really love the thing...great size, weight, good optics which are sharp from 24-70. Everything looks good. Only issue I have is the optical quality at 70mm with something close up. By close I mean less than approximately 2 feet away from the lens. At this distance the focus point is rather blurred. If you switch to macro mode (the start of macro mode) it is still able to focus at these distances and you get very sharp results.

You can see this effect here at the bottom of the page:

http://www.photozone.d​e …f/798-canon2470f4?start=1

I'm just wondering if this is entirely normal for all copies of the lens or if I should be swapping mine. I mean...its not a deal breaker but it is annoying to have to remember to shift into macro mode if you want to take a picture at 70mm decently close up. The effect falls off with distance and by 3 ft or so everything looks normal.

I don't own this lens, so feel free to ignore this post. The way I understand your issue, it is called 'residual spherical aberration', which means, the focus point shifts when stopping down at close distances. Near MFD, if you shoot wide open, this problem does not exist, because you are focusing and shooting at the same aperture. The further you stop down, the worse it gets. The good news is that once your focus is out to about 3', the deeper DOF covers the problem. The 17-55 also suffers (minorly) from this issue, and it is one of the best efs lenses Canon makes. The solution is not to stop down too much while focusing at 18", which sounds pretty easy. That is getting into macro lens territory, which this lens does quite handily from what I hear.

Nope not quite what I am talking about...this has nothing to do with stopping down...the lens is simply soft at close focus distances if not in macro mode. I've found a few other threads where other people talk about it....apparently the Tamron also does this to some degree.

Read Bryan's review of this lens at TDP. He explains it much better than I can. Link: http://www.the-digital-picture.com …L-IS-USM-Lens-Review.aspx

Rare are the lens with a macro switch, so if there is a macro switch it's because you need it

I would like to test my copy, but I have no test chart to shoot