24-70 f2.8 not sharp in corners until 35mm (on DX)

[paul.droluk]

I just started testing my new D300 and the 24-70/2.8. I compared this lens against several of my other

Nikon lenses and am a bit disturbed at its poor performance in the corners at the wider end, as compared

to the following... at 24mm (24/2.8 AIS, 14-24/2.8, 17-35/2.8)... at 28mm (17-35/2.8, 28-50/3.5 AIS).

 

At 24mm, the lens is actually quite poor in the corners (compared to all others)... and this is only DX

format. I can't imagine how bad it will look when my D3 comes in.

 

At about 35mm, the 24-70/2.8 competes with (but not better than) the 35/2 AIS, 17-35/2.8, 28-50/3.5

AIS. From around 50mm and up the lens is actually quite sharp.

 

So, has anybody else tested this lens in a similar manner? What have you seen? Do I have a bad sample, or

is this the normal performance of 24-70/2.8 at the wider settings? Lastly, does anybody know if the 28-

70/2.8 perform better?

 

Here's a corner shot from the 24-70 @ f8. Tripod mounted...

[paul.droluk]

Here's the same shot using the 17-35 A f8... neither image was sharpened...

[frank_skomial]

Are you sure you did not get motion blur ? or focus problem ?

Have you used fast shutter or tripod ?

 

The Nikon published MTF charts for the new lens were much better than the old lens you compare to. Here it goes my

thoery on usefulness or not of the MTF charts.

 

Your finding is realy disturbing, but comes right on time for me, as I was about to purchase this lens. I will neeed more opinions from users.

 

Thank you for providing the photos.

[tonybeach]

Assuming you used a tripod, mirror lock-up, and were properly focused, then it appears to be a bad copy. I would send it back and get another one. This lens should be nearly perfect even wide open, even in the corners (especially on a DX camera).

 

http://www.photozone.de/8Reviews/lenses/nikkor_1735_28/index.htm

 

http://www.photozone.de/8Reviews/lenses/nikkor_2470_28/index.htm

[elliot1]

I tested the 24-70 against my 17-55 on my D80 at f2.8 at various focal lengths. They produced virtually identical results for both sharpness, color and contrast.

 

I agree with Anthony, you probably have a bad copy. And I really liked the range on the DX sensor, although on the wide end it is not very wide.

 

I guess if you can afford two lenses, the 12-24 and 24-70 make a perfect set of lenses for DX format.

[bjørn rørslett]

I have used three different samples of the 24-70 on DX and FX cameras. None of them have had significant curvature of field or vignetting on either format.

 

I have read a lot of reports from users claiming there are possible QC issues with the 24-70 (dust specks inside, corner unsharpness, vignetting), and have compiled a list with web links and forwarded this directly to the Technical Head of Nikon Europe BV. I'm awaiting an answer from him.

[Kent Shafer]

Here are some tests I just did at 24mm about 12 feet away from a bookshelf using a strobe. Can't say I'm thrilled with the 24-70's corner sharpness either, though I don't have another pro quality lens with that focal length to compare it to. It obviously compares very favorably to the 18-55mm f/3.5-5.6 kit lens.

[Kent Shafer]

Next image.

[Kent Shafer]

Third image.

[Kent Shafer]

Last image.

[vivek iyer]

<i>..and have compiled a list with web links and forwarded this directly to the Technical Head of Nikon Europe BV.</i>

<p>

Constructive, Bjorn!

[jwhite3.0]

Bjorn, interesting comments, mine came with considerable dust right behind the first outer element. However, I figured whenever I had it calibrated down the road I would have it cleaned, not enough of an issue to return and wait for another one. Other than the dust mine has been very sharp throughout the whole field on a DX sensor. Anecdotally, it is as sharp or sharper than my Canon 24-70.

[dan_brown4]

Point of refernce. Here is my Sigma 18-50/2.8 EX HSM shot at 24mm, f8 D200 L-Fine jpg,

factory defaults, 100% crop, no post processing. Shot woth strobe. First shot is center

frame, second is extreme. Same image content because i moved the camera/tripod.<div></div>

[dan_brown4]

Now the corner:<div></div>

[dan_brown4]

Correction: the pict bove is the far side of the frame. This one is the far corner:<div></div>

[Kent Shafer]

Not to beat a dead horse, but following Dan's lead I repeated my test shifting the viewpoint so that corner and center crops would have similar subject matter.<p>

The corner is obviously softer than the center, which doesn't seem consistent with Bjorn's and Photonet's results. I must have a bad one. What a drag.<p>

Both shot with D300 in large fine jpg, factory defaults, with strobe at f/8, no PP, 100% crops.

[tonybeach]

Well, reading about Paul's, Bjorn's, and now Kent's experiences; this makes me a little wary about the QC of this lens. So far the initial reports for the D3 and D300 have been very good, but with 4 major releases it would appear that this lens may be the problem child (still waiting to hear more about the 14-24/2.8).