What's going on with my lens?

ptrmcky

I've recently starting having issues with my Nikon 24-70 2.8. When going through the images from my last wedding I noticed some weird stuff going on with the focus. Although it has been focused properly in the middle, focus seems to go way off on the left side of the image.

The lens was performing fine before so I don't know what's going on or how to remedy it. Anyone seen anything like this before and how much it will cost to get fixed?

Here's some sample images. Shot at f5 at 40mm.

sevencrossing

You (or the camera) seems to have focused on the brick wall rather than the Bride

ptrmcky

I know it sort of looks like I just can't focus. But as you can see the close crop in the middle shows the bride on focus.

These photos below show that it isn't a focusing error as everything would be very out of focus if I missed it here. The photos above shows how the focus seems to fall back until the wall is in focus.

sevencrossing

I know it sort of looks like I just can't focus. But as you can see the close crop in the middle shows the bride on focus.

If you are not spot on with focus, the edges will become blurred, before the center

what focus setting are you using ?

groups will always show up any lens defects

I suspect you might be better off with a prime at F8

Ironheart

He said it was fine before and just started happening, so assuming this isn't your first rodeo, err, wedding, it's possible you dropped or banged the lens hard enough to de-center one of the optical elements. It's also possible that the camera is back focusing for some reason, and the DoF is masking the problem in the center, but not at the edges. Unless you are shooting with a Zeiss micro-planner, the field of most lenses is not anywhere near flat.
Best to send the combo off to Nikon, or do a same day tune up if you are close to a service center.

ptrmcky

I'm a full time portrait photographer, so I know how to focus a shot. The problem can be seen in every shot on both of my camera bodies, and it doesn't happen on any of my other lenses, which are all primes and mostly shot at f2 or below. Also, it only really affects the left side of the image, the right side remains in focus.

I'm usually pretty careful with my gear, so I don't know how it could have picked up a knock. Maybe something just wiggled loose over time.

Gonna do some test shots with it now so I can get an idea of what the focal plane is doing.

sevencrossing

I
I'm usually pretty careful with my gear, so I don't know how it could have picked up a knock. Maybe something just wiggled loose over time.

from what you are saying, it does look like a problem with the lens
Even Nikon glass does need maintenance from time to time

proudgeek

I bought a used version of this lens a few years back and encountered a similar issues. Purchased it right before a trip to California and did a cursory check in the shop (I trust these guys and as a result didn't look too carefully). However, when I got home from my trip and started looking at images, I saw this:

Take a look at the light posts and fencing on the right vs. the left. The lens was still under warranty so we sent it back to Nikon and they replaced/fixed a ton of stuff; more than I can remember. Haven't had an issue since. I only bring this story up because your problem seems pretty similar to what I was experiencing.

Good luck.

Ironheart

@proudgeek, yours looks soft on the right side if my monitor/eyes are not deceiving me ;-)
@ptrmcky, I would send it in
If you are a pro, you should be an NPS member and get priority support. If I were a pro, I'd either go the route that @pistnbroke does and go cheap and highly redundant, or the other way with a few expensive pieces, but send them in every year or two for a CLA, on rotation so I was never completely down.

proudgeek

^^Soft as a baby's bottom. All good now.