Focus Issues with EF 24-70mm 2.8 usm

[cqphotographics]

So I know this lens has been criticized for having back focusing issues and the new version supposedly fixes those problems. However the prices for these lenses used and in good condition seemed to make sense. I shoot lots of landscapes and video so auto focus isn't' the biggest deal but ideally a lens like this would allow me to shoot more portraits and events, anyways thats beside the point.

Is there a good standard way to put this lens to the test and check how well the focus is functioning and how sharp it is?
I shoot with the 5D mkII which also doesn't have the greatest AF abilities.
But i'd just like to know if theres a good way to go about evaluating the lens because if it isn't up to par I can send it back and try a different one.

 

[yellowkamper]

I have the 24-70 F4 and it has bad focus shift, I have set the focus adjust to -20 and it will focus correctly at F8 .
any other aperture and it is off so I end up just using F8. It has been back to Canon but is no better. I did send my body back at the same time and have tried it on a 1Dx and it still has focus shift.

 

[cqphotographics]

I did a focus calibration test using a Moire pattern with my 5D hooked up to an hd monitor, used the micro adjustment tool in the menu and settled on +3 which has so far seemed to get everything in focus! More testing tomorrow but its looking good.

 

[drmikeinpdx]

LensRentals.com had a good article on these lenses:

http://www.lensrentals.com/blog/2011/10/the-limits-of-variation

I never bought this lens because my Tamron 28-75 was doing the job for me. I did rent one from Lens Rentals to see what I was missing and it had absolutely horrible focus shift as you zoomed through the range. I assume that copy was worn out as described in the article above.

 

[cliffwang]

Is the lens 24-70mm MK1 or MK2? I don't have MK2. However, many reviews say it's an excellent lens. If you have 24-70mm MK2, that lens should be under warranty. You can just send it back to Canon for adjustment for you. If you have 24-70mm MK1, that's quite normal for me. My old MK1 also had focus and IQ issue. That also happened on my another colleague's 24-70mm.
By the way, if you do need video feature, you might want to have IS lenses. Both 24-70mm MK1/MK2 doesn't have IS feature.

 

[LetTheRightLensIn]

So I know this lens has been criticized for having back focusing issues and the new version supposedly fixes those problems. However the prices for these lenses used and in good condition seemed to make sense. I shoot lots of landscapes and video so auto focus isn't' the biggest deal but ideally a lens like this would allow me to shoot more portraits and events, anyways thats beside the point.

Is there a good standard way to put this lens to the test and check how well the focus is functioning and how sharp it is?
I shoot with the 5D mkII which also doesn't have the greatest AF abilities.
But i'd just like to know if theres a good way to go about evaluating the lens because if it isn't up to par I can send it back and try a different one.

Just set it to f/2.8, aim it at end, mid and long at an angle at a crack in the sidewalk using single center point AF. If the DOF doesn't seem centered properly then adjust it in the AF manual AF calibration settings for that lens and keep adjusting until it seems centered properly. If you need much different values at long vs mid vs wide end then send it back as only the very newest bodies can adjust lenses for long vs wide end.