Sony FE 135mm f1.8 GM Early MTF Results

As is sometimes the case, I got access to a couple of pre-release copies of the new Sony FE 135mm f1.8 GM lens. Of course, if I get access, it gets MTF bench tested. I mounted the first one, sipped my coffee and then lost my mind and started shouting various expletives, enough to bring Aaron running in from the other room to see what I’d broken.

I hadn’t broken anything; I just saw MTF curves higher than anything I’d ever seen in a normal-range lens. (Lenses like 400mm f/2.8 super telephotos, are about this high. But those are super telephotos. And f/2.8.)

Anyway, I tested the two copies we had and sent a subtle note of congratulations to some friends at Sony. The note turned into a video conference with one of the designers of the lens and some phone calls that went like “you can write up those two copies” and “no, I only write up 10-copy sets”. This turned into Sony giving me to access to 8 more copies and permission release the test results early.

Sony 135mm GM Rentals

So, this write up is my usual MTF post; 10 new-from-box copies tested and averaged. They are Sony’s own copies, however, not the usual lenses we’ve bought off the shelf. I’ll repeat the test in 6 weeks when we get our own copies, but I have no reason to think it will be different. And just to be clear, Sony didn’t hover over me or approve my results; they’ll see this blog post for the first time exactly when you do.

A Bit About the Lens

I was permitted to share a bit of the background I was given on this lens; it has some new features. The paired linear motors moving two separate focusing groups haven’t been done before. There have been some attempts at paired focusing groups in zooms, but not in primes, and the pairs have generally been one ring and one linear motor. Also, these are new linear motors (depending on how you count, 4th generation) that are much more powerful and robust than earlier ones. This is the same motor design used in the Sony FE 400mm f/2.8 GM OSS lens, which we showed you in the teardown of that lens.

If I understand correctly, this focusing system allows the 135mm f1.8 GM to execute up to 60 AF instructions per second. {Correction: I misunderstood this part during the teleconference. What was said was that the A9 can give 60 instructions per second, and that this and the 400 f/2.8 come closest to keeping up with that.} That is faster than anything else Sony has made and does it to a higher degree of accuracy than they’ve achieved before.

Optically, the lens has what Sony’s engineers call the largest ‘extreme’ aspheric element ever made, and it’s up in the front of the lens, which they say helps both sharpness and bokeh. I think ‘extreme’ aspheric may be more of a marketing, than an optical, term. But what was very clear is they have (and I saw micrographs to demonstrate it) been able to polish this aspheric to a smoother degree than has been possible, reducing or eliminating any onion-skin bokeh.

Sharpness Testing Sony 135mm GM

There were more features, like the 11-blade aperture and the aluminum-magnesium composite chassis (the same material used in the Sony 400 f2.8 again). I’m not trying to make this into a lens review; it’s just my report of MTF tests. But I wanted to let you know that I was really impressed by the discussions I had with Sony engineers. As many of you who follow this blog know, ‘impressed’ has not always been my opinion of Sony’s lenses. But I’m impressed this time.

MTF Results

Let’s make this simple and straightforward. In the center, that’s the highest MTF I’ve seen on a non-supertelephoto lens. The highest. Let’s put particular emphasis on the purple line, which is 50 lp/mm. That’s a higher frequency than any manufacturer tests (that we know of), appropriate for fine detail on the highest resolution cameras. We would consider an MTF of 0.5 at 50 lp/mm to be very acceptable. This is hugely better, nearly 0.8 in the center. We’ve never seen that kind of resolution before., 2018


The MTF drops away from the center, of course, but even at the very edges, the readings are still quite high.

Let’s compare it to the Sigma 135mm f1.8, which until today was the sharpest 135mm we had tested. In the outer 1/2 of the image they’re pretty even, but in the center half, the Sony GM is dramatically better, especially at higher resolutions., 2018


I’ll also throw up a comparison with the Zeiss 135mm Batis, which is really excellent, although not wide-aperture. The Batis has a considerable advantage since it’s being tested at f/2.8. Even at f/1.8, though, the Sony 135mm GM is clearly better in the center half of the image. 2018


But Wait! There’s More!

Aaron brought up that this was the highest center resolution either of us remembered seeing on standard testing, with 50 lp/mm reaching a ridiculous 0.78 MTF. We have, in the past, tested lenses at a higher frequency for ultra-high resolution sensors (150 megapixels). We found that a lot of lenses that were really good at standard frequencies died quickly at higher frequencies.

So we tested the 135mm GM up to 100 lp/mm, something we don’t normally do., 2019

These results are insanely good. At 100 lp/mm the Sony 135mm f/1.8 GM has a higher MTF than most excellent primes do at 50 lp / mm. If you don’t speak MTF, basically that means this lens can resolve fine details that would be a blur on excellent lenses.

Back when we were doing that ultra-high resolution testing we tested all the lenses stopped down to f/2.8 or f/4; there was no way to get the kind of resolution our client needed otherwise. So we tried the 100 lp test at f/2.8. Honestly, I thought the resolution wouldn’t go up all that much. As is so often the case, I thought wrong., 2018

No lens we’ve ever tested has resolved 100 lp/mm this well at any aperture. One other lens was close, but I can’t tell you the name of it. We were under such strict nondisclosure that we never referred to it by name. It was just referred to as ‘the lens in question’ and was a huge prototype. But even that lens wasn’t quite this good at 100 lp/mm.

What does this mean for you? Well, in a couple of years if you are shooting a 90-megapixel camera, this lens will be the one that wrings the most detail out of that sensor. Right now it looks at your 43 megapixels and goes, “that’s cute.”


This has been an MTF test. It has only been an MTF test. If it had been an actual lens review, I would have 762 images showing you pretty models, dramatic landscapes, and bokeh examples. Lens reviewers will do that in a while; be patient.

But as far as the test goes, the results are pretty simple. This is the sharpest lens we’ve tested. Period. (At last count, that’s out of 300+ lenses tested.)


Roger Cicala and Aaron Closz

March, 2019

Author: Roger Cicala

I’m Roger and I am the founder of 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
  • Claudia Muster

    Sounds sensible. Thanks.

  • I’m not going to publish variation on manufacturer’s lenses. Not till we get of the shelf copies.

  • Claudia Muster

    A word about copy variation? And I’m sure missing that nice colourful field curvature plot.

  • Erkan Özgür Y?lmaz

    OMG I’m now blown away, I know how sharp the Zeiss is, and this charts makes sense now. Thanks Roger.

  • Don’t have the mount to test Fuji yet.

  • Carleton Foxx

    Shouldn’t we all be freaking out over moiré with such a high res lens?

  • Amazing! Thank you very much for the test, Roger. Much appreciated.

    By any chance, would you do a test on the Fuji GF110mmF2 lens?

  • A Canuck

    This is good reviewing at its finest. Thanks, Roger. The lens does look as if it will be pretty awesome. I like my Batis 135 all the same (I do a lot of hand-held shooting–it’s nice and light for such a long lens).

  • Marvinski

    Yes, that would be a very interesting discussion.
    By not going off topic too much…even tho I already did….I just leave one more piece here…just food for thought to save it for another day.

  • Unrest

    True, and when Nikon, Sigma, Zeiss, Leica, etc. play in the same market as you play….better to have good lenses.

  • Unrest

    + 1. The Nikon 400 2.8 FL is still king at that focal length!!

  • PJ Smith

    I know, I didn’t say they were bad lenses or not sharp. I just prefer the Nikon design and I would bet my life that the Nikon’s have a T-Stop lower than the other two. You can either have 3-4 large and expensive elements at the front or 1 element at the front and tons of little elements in the rear to correct for the lack of them at the front. They are all great lenses and anyone would be happy with any one of them. I’m not sure what you mean about teleconverters, because the newest Nikon TC-14E III is amazing. I have one and can not really see any loss of image quality and if I had to I would say 5% loss of sharpness.

  • iKonOkLasT


  • iKonOkLasT

    Not really. Something happened with the early Zeiss ZE/ZF2 datasets and Roger has never really corrected them or amended the older articles. Should also get in touch with Bryan Carnathan as I believe TDP is using some of the older data.

  • T N Args

    Thanks Roger, it’s very interesting.

  • Akvinat

    It will be like with car top speed. Some cars have higher top speed than others, but it rarely matters…

  • monopodman

    What about the new Canon 400 III? It uses the same “cheap” technique as Sony and its MTF is almost indistinguishable from the 400 II (and for 600 III it’s exactly the same as II)

    P. S. Use Canon JP since they haven’t updated old lenses to their new MTF calculation technique for their US website

    Also, if we take teleconverters into account, then Canon and especially Sony are better. I can’t wait for native mirrorless TC (and native primes) for the Z and R mount

  • Stephen Cassidy

    How does the lens compare to the Sony A-mount Sonnar T* 135mm f1.8 Zeiss lens?

  • PJ Smith

    The new sony 400mm 2.8 is a sharp lens, however the Nikon 400mm 2.8 is sharper. I’ve seen both MTF charts, and I own the Nikon 400mm 2.8 VR. The 800mm 5.6 however is probably the sharpest lens in current production. It’s near perfect and it should be for $16,000. The Nikon lenses have 4 large elements, 2 of them being ED elements in the front of the 400 and 800, where the Sony has only one large front element. Sony cheapen out on the new 400mm 2.8, and had to overcorrect for it in the back part of the lens. There is only one element in the front 60% of that lens.

  • My understanding of the Minolta/Zeiss differences and origins is different, and I’m sure would be a fascinating discussion… but much off topic here.

  • Gerard, I do plan to, but we haven’t had a mount made yet.

  • Mike Earussi

    With the extra added AF motor (hopefully) increasing its AF speed, it has the possibility of being an excellent sports and action lens. If fact this may prove, under real world conditions, to be more important than its exceptional resolution.

  • monopodman

    I’m sure that I won’t. But I expected the GM to be slightly worse than Sigma in MTF, not better!

    The GM is worth the money because it’s lighter / smaller and guarantees the best AF performance.

  • monopodman

    I’ve seen “professional” portrait photographers whose every photo had noticeable handshake and misfocus. And some even use top of the line lenses (85/1.2L, 200/2L, Sigma 135/1.8 etc) and somehow claim they appreciate their superior resolution!

    But I’m still sure that it’ll be possible to extract this lens full potential with proper handholding technique and fast SS. And honestly, I don’t care if I’ll be able to see the difference between the top 135mm lenses because those are the best lenses optically in absolute terms after supertele primes.

    Also, I think this lens is targeting sport and action as much as portraiture

  • monopodman

    Won’t they inherit the lenses as well?

  • monopodman

    I think it’ll be very similar. It seems that regular primes only now approach the performance level of supertelephoto primes and that’s why we see such incredible lenses like 135 GM – so much better than older designs. However, 400/2.8 were already at the top of optical excellence for years.

  • appliance5000

    ow does the canon 135 tilt shift compare? Mine seems so sharp I can hardly imagine something sharper – my eyes hurt looking at a photo.

  • Gerard R

    Roger, I read that Leica tests their SL line of lenses at 50 line pairs/mm. The 90mm APO SL Summicron shows around 85% contrast for 40 lp/mm in the published Leica MTF charts.

    Have you all planned to test the Leica SL lenses? The MTF of the new 35 APO SL Summicron presented at the latest LHSA conference showed above 90% contrast for 40 lp/mm, which should be on par with this 135/1.8 Sony.

  • Accutous

    That this beat Sigma is pretty darned incredible. Now wrinkles will look like butt cracks.

  • Carleton Foxx

    If I am not mistaken, that particular optic is one of Roger’s favorites, so maybe it’s not the best example of a ‘normal’ lens.

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