Equipment

Sony FE 16-35mm f/2.8 GM Sharpness Tests

Well, I’ll say to start with I’ve probably had more requests for the Sony FE 16-35mm f/2.8 GM MTF tests than any lens in recent memory. People are excited about it. About half the requests have been very reasonable “I’m hoping to see MTF results before I decide between this lens and that.” And, as has become far too common with Sony lenses lately, about half were fanboyish “I can’t wait to see the new Sony FE 16-35 smoke the Canon 16-35mm f/2.8 Mk III.”

Sony 16-35mm GM MTF Charts

For those who don’t like to read, I’ll save you lots of time. This is a very good lens with interesting characteristics that I think will make it a photographer favorite. It’s expensive, but not massively more than the Canon 16-35mm f/2.8 Mk III. But if you’re a fanboy looking for numbers that ‘destroy’ the competition, you’ll have to go to one of those number-generating sites that say it pulled 72.3 smoke units out of their butt. This post won’t be for you.

MTF Curves

As always, these are the average curves obtained by testing 10 lenses, each at four different rotations from edge-to-edge. So each point on the MTF graph is the average of 80 readings for each frequency.

16mm

The lens is at its best at 16mm, where it’s sharp in the center even at higher frequencies. It maintains sharpness very well through the middle half of the image, then fades a little bit, but not much.  There is a little astigmatism-like separation of the sagittal and tangential curves in the outer half, but again far less than we expect in a wide-angle zoom. This is an excellent performance at 16mm as I’ll show you in some later comparisons.

More than just absolute numerical performance, the MTF curves suggest a very smooth, even performance across the entire image frame. That’s something few wide-angle lenses of any type do, much less a wide-angle zoom.

Olaf Optical Testing, 2017

24mm

Like most wide zooms, things aren’t quite as sharp at 24mm, both in the center and out towards the edges. Still, this is a very good performance, and the lens is still going to generate nice, sharp images here.

Olaf Optical Testing, 2017

35mm

Following the usual wide zoom pattern, things fall off a bit more at the long end of the zoom range. It’s not bad, by any means, but not nearly as sharp as it was at 16mm. As is the usual case with wide angle zooms, at 35mm you’d probably be better served by changing over to your 24-70mm lens, but this is still very usable.

Olaf Optical Testing, 2017

Full-Field MTF Patterns

For those who don’t like MTF, this provides a nice, intuitive look at the relative sharpness of the lens at various focal lengths.

These are done at 30 line pairs/mm and are the average of Sagittal and Tangential numbers, so we’ve lost a lot of data that you can see in the MTF graphs in exchange for a more intuitive overview. Basically dark blue is as sharp as you would like; lighter blue is reasonably sharp, green and yellow is somewhat blurry but can be improved with some aggressive post processing.

16mm

Olaf Optical Testing, 2017

24mm

Olaf Optical Testing, 2017

35mm

Olaf Optical Testing, 2017

 

MTF vs Field vs Focus (AKA Field of Focus Curves)

These are possibly the most useful curves we can give you. I need to point out that these are not the average of 10 lenses, rather they are examples of a single lens that was fairly representative. Since it is a single lens, you may see a little field tilt here or there, most zooms have some. (If you’re wondering why we don’t average 10 of these, it’s because they take about 30 minutes each to do and have enough data points that trying to average them would bring our computer to it’s knees.)

16mm

A very slight mustache field at 16mm. This is excellent, though, for a 16mm lens. Notice that the sagittal and tangential curves match up very well, which we expected after seeing the MTF curves above.

Olaf Optical Testing, 2017

24mm

The field flattens somewhat at 24mm. This copy is slightly decentered at this focus distance and has a little tilt in the tangential field. This isn’t severe, by any means, but would be noticeable if you pixel-peep. If you untilt the tangential curve in your mind, you can see that at the edges the tangential field is not lined up with the sagittal field, which we saw in the MTF curve again.

Olaf Optical Testing, 2017

35mm

At 35mm the sagittal field is quite flat. The tangential field is flat in the middle 2/3 of the image but shifts pretty dramatically at the edges. There’s going to be edge astigmatism at the 35mm focal length. This copy is well centered, but slightly tilted. The tilt is slight enough (draw an imaginary line across the graph at “0” on the X axis) that it probably is not noticeable even with pixel peeping. Probably.

Olaf Optical Testing, 2017

Comparisons

Sony FE 16-35mm f/2.8 GM vs Canon 16-35mm f/2.8 L Mk III

The Canon 16-35mm f/2.8L Mk III is arguably the best 16-35mm f/2.8 lens, and therefore we consider it the standard at this focal length.

16mm

The Canon has an amazingly high resolution right in the center, especially at higher frequencies where the difference between it and the Sony is dramatic. But the Sony’s smooth curves give it better resolution in the outer half of the image, and the Sony has less sag-tan separation (this can be caused by either astigmatism or lateral color) so it’s likely to have a smoother look and could have smoother bokeh (lots of other factors contribute to bokeh).

Olaf Optical Testing, 2017

As an aside, I’ll use this as a good example of why single-number ratings are so silly. If you weight the center of the image, the Canon’s going to have a higher rating. If you rate the entire image evenly, they’re going to be pretty equal. If you rate astigmatism as a huge problem, the Sony will have a better rating. My non-numeric rating is they are both excellent, but I expect they’ll have a very different look, and different people will prefer one over the other.

24mm

At 24mm center resolution is pretty equal. Throughout most of the image the Canon maintains slightly better resolution, although it drops off at the edges.

Olaf Optical Testing, 2017

35mm

The 35mm the Canon has a bit better resolution through most of the image, and the sagittal-tangential difference is now clearly better on the Canon. They’re both good though, and this is not a huge difference by any means. As I mentioned earlier, if you’re carrying a 24-70mm f/2.8 lens you’ll find it’s slightly better at 35mm than either of these, but both are still very acceptable.

Olaf Optical Testing, 2017

 

Sony FE 16-35mm f/2.8 GM vs. Sony 16-35mm f/4 ZA OSS

This is a logical comparison that will be a choice for a lot of people. The ZA is a very good lens and significantly less expensive.

Remember the ZA OSS is being tested at f/4, the GM at f/2.8, so we would expect the ZA to have better MTF performance.  (Before you ask me to test the GM f/4, the cost of a 10-lens, 3-focal length run is $3,700, so if you’d like it done just send a check with your request.)

16mm

At 16mm, the ZA does have higher resolution in the center 1/3 of the image, although things would probably be even if we had tested the GM lens at f/4.  Away from the center, though, even at f/2.8 the GM is clearly better.

 

Olaf Optical Testing, 2017

24mm

Things are more even at 24mm. The ZA is better at higher frequencies in the middle half of the image, but there is still far more sagittal-tangential separation on the ZA lens.

Olaf Optical Testing, 2017

35mm

Things change a little at 35mm, where the ZA actually has less sagittal-tangential separation, but again the GMs performance at f/2.8 is very similar to the ZA’s performance at f/4. The bottom line is if you want to shoot at f/2.8 you don’t have to give up resolution to do so. That’s a very big deal.

Olaf Optical Testing, 2017

 

Sony FE 16-35mm f/2.8 GM vs. Sony FE 12-24mm f/4

I put this comparison up because I know some people are interested in it. Obviously, the 12-24m is much better from 12-16mm. I don’t have 16mm data on the 12-24 because we only test 2X zooms at their extremes. But I can compare them at 24mm. There’s not a lot of difference between the GM at f/2.8 and the 12-24mm at f/4.

Olaf Optical Testing, 2017

 

Variation

The FE 16-35 f/2.8 GM repeats a pattern we’ve seen fairly often, but it’s a bit more extreme than usual. At 16mm and 24mm it’s pretty consistent. At 35mm it’s a random crap shoot. How random?  At 35mm, copy-to-copy variation is, well, going to cause some issues.

Let me just show you the full field displays for the first 11 lenses I tested at 35mm. These are the ones that went into making the average in the display above.

Olaf Optical Testing, 2017

I’m not posting the 16mm and 24mm variations trying to keep this reasonably brief, but at those two focal lengths there wasn’t much variation. We had one copy that was truly bad out of 11 tested at 24mm, but that copy was excellent at 16mm and 35mm. All of the copies we tested were very similar at 16mm.

Conclusion

The Sony 16-35mm f/2.8 GM lens is an excellent optic at 16mm and 24mm. If you want to shoot wide at f/2.8 on an FE mount camera it’s probably the optic of choice. The 16-35 ZA f/4 is a good lens and a lot cheaper if you don’t need f/2.8, but the GM is just better optically. It’s not better or worse than the Canon 16-35mm f/2.8L Mk III, it’s different, and some people will certainly like it’s look better.

But if you plan on using it at 35mm, which I generally don’t recommend for wide zooms if you have alternatives, well, you’re probably going to go through several copies before you find the one you want. Personally, I think it’s a really good 16-24mm f/2.8 zoom that can be used at 35mm if you have to.

 

Roger Cicala and Aaron Closz

Lensrentals.com

August, 2017

Author: Roger Cicala

I’m Roger and I am the founder of Lensrentals.com. Hailed as one of the optic nerds here, I enjoy shooting collimated light through 30X microscope objectives in my spare time. When I do take real pictures I like using something different: a Medium format, or Pentax K1, or a Sony RX1R.

Posted in Equipment
  • Messier77

    Thanks! Seems like the 12-24 is the better bet for getting a good copy to shoot UWA.

  • There’s more variation with the 16-35, most notably at the 35mm end.

  • Messier77

    Roger:

    How would you compare the copy-to-copy variation between the 12-24 f/4 and the 16-35 f/2.8 GM?

    Thanks

  • vasile

    all the best and God bless your family.

  • I would personally, but I don’t really need f/2.8 in a wide zoom and I do like shooting ultra-wide. Others would feel differently.

  • I’ve had the Batis on my to-do list for a while, but family illness severely reduced my time in the office this summer and our intern had to leave early, so we’re months behind.

  • vasile

    thank you roger. it will be nice , sometime in the future, to have them compared with the only ultra-wide native prime (the batis 18). and why zeiss are not making any fast ultra wide primes ? (because sony didn’t do it for the A-mount either…)

  • Steven Kornreich

    Roger, If you already own the FE 24-70/2.8GM, would you recommend the 12-24/4 over the 16-35/2.8GM ?
    Thanks

  • Hi Michael, I don’t do vignette testing, I’m afraid.

  • Michael Fang

    Thanks Roger for the review, have you tested vignetting wide open @ 16mm? It is pretty severe on the Canon’s 16-35 III.

  • VPR

    Sorry, all… I meant to write “Batis”

  • Sanjeev Das

    OTOH, if you want some wide angle shots of the progress of your bathroom…

  • Hi Nathan,

    Our testing is done vertically with the lens pointed up. When we used Imatest and an older optical bench we did test horizontally and on extending barrel zooms it wasn’t uncommon to see drop as you suggested. Large lenses were always supported by the lens, not the camera, so I can’t say anything about sag at the camera mount in general, although I’ve seen it in real life.

    IS units that don’t physically lock down present a problem when testing in that the lens has to be given a ‘quiet down’ time period between measurements. This also happens with very large or long focal length lenses. For example we pause a fraction of a second between each movement/measurement for a non-IS standard focal length lens, but may have to pause a couple of seconds between each measurement for a non-locking IS unit to settle down.

  • Chik Sum

    Thanks Roger, but if then I can imagine the coming problems with the 35mm end, it looked way out to be easily pixel peeping noticable

  • Nathan Connolly

    Hi Roger, I’m interested in your testing technique for zooms. I asked about IS lenses a few weeks ago, and whether or not they positively locked down their shaky elements with IS off or when unpowered, and this is sort of in the same area. Do you test the zooms pointed straight ahead, or down, or up, or what? My point being is there any mitigation for the mechanical deflection of the extending zoom element as it moves outwards, owing to gravity? Do you find that the droop is substantial in any new lenses, or that it is optically significant? And on a related point, do you see a difference in simply physically long or heavy lenses, deflecting from the lens mount under their own weight? And even if you do test the lenses pointing straight up and down, has it occurred to you to try and measure such a change when shooting horizntally, as one normally would? I know that it seems like splitting hairs, but surely this must have crossed your tortured scientist’s mind at some point…

  • Zoltán Üveges

    Is dust a common issue with (brand new) GM lenses? I’m about to switch to Sony FE system and a bit worried about the dust sealing. Have you got your second copy already?

  • tomskyphoto

    Looks like a very good lens but then all the GMs didn’t disappoint so far. Wide angles also seem to become the domain where there is a mirrorless advantage when it comes to size and weight. Like the 12-24/4 G the 16-35 GM is remarkably small and lightweight for its specifications.

    Won’t get it as I already have an excellent copy of the 16-35/4, at least between 16 and 24 mm, while it’s a bit meh at 35. But then this seems to be not much different with the GM either.

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