Nikon 24-70mm Astigmatism

[Vanessa D]

I bought a used Nikon 24-70 from B&H photo last week with a rating of 9+ on their website, which means it's in excellent condition.  Today I am calibrating all my lenses with Reikan FoCal Pro.  When doing this lens it tells me that the lens astigmatism is higher than average and under Consistency Of Focus it says There is more variability in your autofocus result than is typical.  It gave me a fine tune of +17 at 24mm and 70mm. 

So are those issues worth me sending the lens back for?  The images are from the final report.  One is for 24mm and other is 70mm.

[Brian]

Here's the thing, the Nikon 24-70 is not #amazeballz sharp, and is at its weakest at both 24mm and 70mm. This is normal, and I'm sure within Nikon's tolerances. Remember, it's a zoom, not a prime. Doing what I call the "Measurebator Tests" will just frustrate you. Virtually ALL digital photographs need some sort of sharpening. See: Damien's Sharpening Class.

What I would do is take your camera and new lens for a workout. Photograph things of all types, near and far. Pixel-Peep. Rinse and Repeat. Figure out which focal range works best, and which ones need a bit more finesse on your part. Figure out how far away your subject is so that the lens performs at its best. Use a tape measure and figure this out. The reason I say this, is say you put AF Fine Tune at +17, what happens when you are at 56mm? Or 35mm? Or 42mm? Or 60mm? You are going to have out-of-focus photos, then the next stop I will see you in is the Focus Checks Section on AD, banging your head against the wall. Life is difficult as it is.

If you find the lens doesn't perform to your expectations after pixel-peeping, then I'd return it and try to purchase a brand new 24-70. Even then I feel that that AF Fine Tune software will find something wrong. In addition, your D750 Auto Focus system needs to be ABSOLUTELY PERFECT in order for those tests to be accurate. Actually, your camera & lens needs to be in a lab, under controlled conditions to really be calibrated together, not on a dining room table. LOL!  I've seem a few photographers who have send ALL of their gear to Nikon to have it calibrated together and guess what? They still were not happy when they got it back. Most lenses like the 24-70 and 17-55 (The DX version of the 24-70,) are at their best when the subject is within 5 and 15 feet from you. If you are really looking for TACK SHARP photos, skip zooms and get primes. I'd say get the new Nikon 105mm f/1.4E, the Nikon 58mm f/1.4G and the Nikon 35mm f/1.4G or the Nikon 24mm f/1.4G. Whatever you do, skip the AF-S 50mm f/1.4G, that lens is a piece of sh*t. Of course, going this route is going to be very expensive compared to your used 24-70.

I really think you need to skip all this calibration stuff and GO OUT AND SHOOT. Again, @24mm and @70mm the Nikon 24-70 isn't at it's best. Many zoom lenses suffer the same fate, but I think you will find is that it's not that bad.  

[Vanessa D]

Thanks for the feedback, Brian!

I got this lens specifically because I am leaning towards doing mainly newborn and maternity sessions and after discussing with MANY newborn photogs, the majority use either the 24-70, the sigma art 35 or the sigma art 50.  I've looked at all the pictures from the photographers as well and felt that since I have the nifty fifty 1.4 already, and a nikon 85 1.8 (which I don't use for newborns), the 24-70 would be best at rounding out my gear.  It was either that or the 35mm art. I also do senior and family sessions on location so the 24-70 would go well with my Sigma 70-200.  Plus, my in home studio is very small, so i don't have much room to step back.  With my 50, I find myself struggling with being back far enough.

I rented a 24-70 last year and honestly, I wasn't that impressed, but I chalked it up to it being either me not doing something right or the lens being a rental, getting beat up and abused.  Now I'm really wondering...  When I got the 85mm and took my first shot, it was awesome. I knew I was keeping that lens.  This one just feels okay....and for the money it costs, I need to love it. 

I will be going out this week and putting both the camera and all my lenses to the test.  My camera just got back this past week from Nikon for the shutter issue they have on recall.  So the inside of the camera is brand new and clean.  As far as being in a lab, well yeah I agree but I did my best with a tripod. ;-) 

I am looking for tack sharp, so maybe the 24-70 isn't going to be the lens for me.  =/

 

[Brian]

1 hour ago, Vanessa D said:

I am looking for tack sharp, so maybe the 24-70 isn't going to be the lens for me.

You are headed to Prime Land and I don't think you will ever be 100% happy with a 24-70. A 35mm is probably the lens you are after, and from the looks of things, a Sigma 35mm ART. The 24-70 is great if you want to run-and-gun, like I do during weddings. Mine is pretty sharp and am quite happy with it. You could do things with a 35, 50 and 85. That's typically the focal lengths that you use the majority of the time when it comes to photographing people. Something wide, something long and something in the middle.

Bottom Line: Return it.