What’s With the “Soft” Complaints?

I keep reading, and occasional get an email, that the 24-70mm is “soft.” 

Nope. Not even close. At f/4 (wide open) it’s one of the sharpest 24-70mm’s I’ve seen. It’s very close to the much more expensive 24-70mm f/2.8E that Nikon launched for DSLRs recently, which in itself is one of the best mid-range zooms on the market. 

So why the complaints?

Well, there aren’t a lot of hypotheses we can make:

  • It’s false postings/emails from people trying to belittle what Nikon’s one.
  • It’s really bad samples of the lens that are getting out. 
  • It’s the Z6’s anti-aliasing filter that’s confusing them.
  • It’s focus shift. 

I think all of the above are basically true. 

I don’t know what it is about the Sony fanboy self esteem, but they seem to think they have to belittle other products to make their choice seem better. There’s nothing wrong with the Sony products, though Sony’s 24-70mm f/4 is one of the weakest performers out there. In some areas, Sony does have a better product, in others, they don’t. Pretty much as things have always been for any of the Big Three camera/lens producers. 

We can’t discount bad samples, either. I’ve seen exactly one so far that was clearly a bad sample. I’m not sure how such lenses get out of the factory, but the one that I saw was obviously defective, and that was clear right from looking through it in the viewfinder. It was like your optician getting your eye prescription completely wrong: nothing looked right about the results from that sample.

The Z6’s AA filter is clearly stronger than the D750’s. I’m not sure why Nikon made that decision, but it certainly impacts how acuity is recorded in your data. Nikon had mostly made a transition to no low pass filtration (even the DX DSLRs dropped it) in the past few years, but now we have a strong AA filter back on the Z6.

But I’m betting that focus shift is the biggest culprit for many of those posts and emails, particularly on the Z7 with its higher resolution. 

A lot of you keep telling me this lens has no focus shift or that the Z cameras do a contrast detect step so there would never be a focus shift that went uncorrected. Nope on both cases. The 24-70mm has a minor focus shift, and it mostly occurs beyond f/5.6. Meanwhile, it’s become clear that the Z cameras don’t operate the same way as many of the previous mirrorless cameras from others, even in AF-S mode. The only time I can force (and verify) that a contrast detect step happens is with Pinpoint AF. Most of the rest of the time in AF-S the camera will simply rely on its phase detect observation and not do a contrast detect followup. In AF-C phase detect is all that’s done.

Why is this important? Because the lens never stops down below f/5.6 when obtaining autofocus. Remember I just wrote that the focus shift primarily occurs below that. So if you set f/11, focus at f/5.6, and no contrast detect is done to verify the focus point, guess what happens? You get slightly soft results. Enough so that you might think the lens isn’t a great performer. 

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