Lensrentals.com has apparently tested the resolution (sharpness) of more than 300 different lenses. In fact, they usually test ten copies of a given lens, just to check if there are any inconsistencies, and ensure that the results from one lens aren’t just a fluke, good or bad.

So, when I tell you that the new Sony FE 135mm f/1.8 GM is the sharpest lens they’ve ever tested, that ought to be worth ten thousand Youtubers or Instagrammers who have ever said this-or-that lens is, simply, “very sharp”…

I mounted the first [lens], sipped my coffee and then lost my mind and started shouting various expletives…I hadn’t broken anything; I just saw MTF curves higher than anything I’d ever seen in a normal-range lens.

Now, for those of you who don’t know who Roger Cicala is, he is a rather hard person to impress when it comes to lenses. His optical testing method, known as OLAF, is likely the best in the business when it comes to cameras and photography.

Aspects Of Image Quality

DISCLAIMER: Of course, sharpness isn’t everything; there are so many other characteristics that make a lens great. Such a caveat must indeed closely follow such bold, high praise as, “sharpest lens ever tested”…

With fast-aperture telephoto lenses, two other aspects of lens performance besides sharpness immediately come to mind: autofocus reliability and bokeh. If those two factors let you down as a photographer, then sharpness alone cannot be enough reason to spend $1,898 on a lens. (You can currently preorder it; expected delivery is some time in April 2019.)

Needless to say, here at SLR Lounge we’re certainly looking forward to reviewing the new Sony 135mm! Initial reports are that it is indeed a great option in those other areas of autofocus and bokeh, so we’re eager to take it out for a spin at some weddings and portrait sessions, as well as potentially some other creative ideas. But, more on that later. Let’s look at the test graphs, since that’s likely the reason you clicked on this post in the first place. We’ll keep it simple and explain what you’re looking at.

Sony FE 135mm f/1.8 GM Lab Test Results

So, just how sharp does “sharpest lens ever” look, in an actual sharpness graph? Alone, the following graph may not mean much, because MTF charts don’t mean very much unless you actually understand the numbers.

I would try and explain exactly what the numbers mean, but here’s the thing: even camera companies themselves don’t use the exact same scales on their own MTF charts, and likely not the same testing methods either, meaning it’s just not very useful to look at one chart and assume you can deduce how sharp it actually is, relative to other lenses.

In other words, forget the numbers themselves, and just know this: the higher the colored lines are, the sharper the lens. The left edge of the graph reprsents the dead-center of an image, and the right edge of the graph represents the edge(s) of an image frame. So, as you might expect, a lens is usually sharpest at its center, and it gradually gets a little softer as you approach the very edges. That’s the important thing here.

Sony FE 135mm f/1.8 GM versus other 135mm prime lenses

Since a single MTF chart isn’t very useful to the average photographer, here’s how the Sony 135 GM performs against the Sigma 135mm f/1.8 Art, a lens which is already known to be incredibly sharp indeed, even on high-megapixel full-frame sensors:

In this MTF graph, the centerline in the middle represents the center of both lenses, and the outer edges of the graph represent the edges of each lens. The Sigma 135 Art is on the left, the Sony is on the right.

By the way, the colored lines, again in simplified terms, just represent various frequencies of fine image detail.  Just remember that the higher the lines, the sharper the lens.

As you can see in the above graph, the two lenses are actually similar at the very edges, however, the Sony is just unprecedentedly sharp in the center of the image.

Here is the Sony 135mm GM versus the Zeis Batis 135mm f/2.8, another modern, very sharp 135mm prime lens:


The Zeiss Batis is, on average, a touch sharper at the very edges, but again, the Sony pulls ahead towards the center. But again, keep in mind that all of these lines are ridiculously high up on the graph. A “decently sharp” lens, in many cases, still has its lowest (purple in this case) lines just barely halfway up the graph, even in the center. Both of these lenses have crammed all possible forms of measurement into their upper ~1/3 of the graph. Simply put: both lenses are astonishingly sharp.

Okay, that’s enough graphs and lab tests. For even more geekiness about “lp/mm” and observations from Roger Cicala and OLAF, read the full article here.

What we should ask ourselves now is, what does all of this really mean?

What we’re seeing is the next generation of lens, that is ready to handle the next generation of high-megapixel sensors. Indeed, you could probably expect this lens to still “look great” on a 75-megapixel camera body! Which does imply that we’ll be seeing such cameras in the coming years.

There’s something else to keep in mind, though: if you’re shooting with “just” a 20, 24, or 30-megapixel camera, to be totally fair and honest, all of these recent lenses are going to seem jaw-droppingly sharp. Sony, Zeiss, Sigma, and Nikon have all delivered exciting new 135mm and/or 105mm prime lenses in the last few years that, in an effort to balance out the geekiness of MTF charts, I should probably jsut describe as “bonkers sharp”.

Would you still see a difference in sharpness between this lens and a much older 135mm prime lens, even on a ~24 megapixel sensor? Of course, but only if you’re using truly perfect shooting technique, but that is the case with any photography scenario where you’d like to see a difference in sharpness.

Why Does This Lens Need To Be So Sharp?

If the Sony FE 135mm f/1.8 GM is so sharp that it easily out-resolves the highest-resolution sensor Sony currently offers, (the 42-megapixel A7RIII, our final review of which is coming shortly!) …what is its real purpose?

In short, this lens is future-proof. Not only is it ready to handle an inevitable higher-megapixel sensor, but it’s also likely ready for 8K video! Maybe we’ll see a Sony camera body that offers 8K video in the coming years, who knows. (Note: we don’t have insider information, nor are there any rumors; this is just an observation on what such a high-resolution lens will be good for.)

Nobody should buy a lens for its future potential only. However, it has always been a good idea to invest in glass that can last you 5-10+ years, if you take good care of it. This indeed appears to be one of those lenses.

What’s Your Creative Idea For A Fast, Sharp Telephoto Lens?

All in all, camera gear is just mean to help you achieve a creative vision. Things like increased sharpness are only meant to allow your equipment to “get out of the way”, and let you do something really cool. The question is, what creative ideas do you have?

Since lab test charts aren’t very exciting to look at, I’ll share an image with you that has been in the back of mind for nearly 5 years now. It’s a still photograph, however, I really wanted to create a timelapse of what was happening at this moment. And that is, the Andromeda galaxy was rising in the night sky, and passing very close to the dramatic, iconic lip of Half Dome in Yosemite National Park. This is something I’ve been wanting to re-shoot with a “flawlessly sharp” telephoto lens:

Andromeda Galaxy & Halfdome, Yosemite National Park
Sharpness and low noise were achieved in this image by stacking multiple exposures and blending the sky exposures with a single ultra-long exposure of Half Dome. To learn about photographing our own Milky Way galaxy, and nightscape photography in general, be sure to check out our Milky Way Workshop!


Andromeda approaching Half Dome, GIF animation
Nikon 85mm f/1.8, cropped to ~135mm. Unfortunately, this lens has severe color fringing in addition to its relative softness, and was unsuitable to create a good timelapse. I hope to re-shoot it someday, with a lens such as the Sony 135mm f/1.8!


So, I’d love to hear your thoughts on all these amazing new ultra-fast telephoto primes that we have been seeing lately! What creative idea would you pursue, if you had an “insanely sharp” 135mm f/1.8 (or 105mm f/1.4) at your disposal? Low-light portraits, astrophotography, or…?

Take care, and happy travels!