Geek Articles

Some New Wide Angle Lens MTF Tests: Sony 24mm f1.4 GM; Sony 35mm f/1.8; Tamron 35mm f1.4 SP

Most of you MTF junkies are aware that I’ve published all of our prime lens MTF curves in a series of articles by brand, and that I said I would just add new lenses to those articles. I recently tested a series of new prime lenses, though, and thought they were also worth putting up together because I think it’s a good illustration of recent trends.

Of course, the Sony Fanpeoples have already launched their usual conspiracy theories about “Roger won’t publish the 24mm test results because he doesn’t want to acknowledge how it kicks everyone else’s 24mm ass.” Wrong, oh ye internet conspiracy theorists. The Sony 24mm f1.4 GM has been available for a while, but honestly, we’ve had trouble keeping enough in stock for me to test it.

I was able to grab the first shipment of Sony 35mm f/1.8 lens right before they shipped out. The Tamron 35mm f/1.4 SP was kind of lost in the shuffle; we’ve had some but it took a while to rotate 10 copies over to the lab to test. And, full disclosure, I wasn’t banging on tables to test it because Tamron always makes good, but not best-in-class, lenses.

A Quick How to on Reading MTF Charts

If you’re new here, you’ll see we have a scientific methodology to our approach, and use MTF charts to measure lens resolution and sharpness. All of our MTF charts test ten of the same lenses, and then we average out the results. MTF (or (or Modulation Transfer Function) Charts measure the optical potential of a lens by plotting the contrast and resolution of the lens from the center to the outer corners of the frame. An MTF chart has two axis, the y-axis (vertical) and the x-axis (horizontal).

The y-axis (vertical) measures how accurately the lens reproduces the object (sharpness), where 1.0 would be the theoretical “perfect lens.” The x-axis (horizontal) measures the distance from the center of a lens to the edges (measured in millimeters where 0mm represents the center, and 20mm represents the corner point). Generally, a lens has the greatest theoretical sharpness in the center, with the sharpness being reduced in the corners.

Tangential & Sagittal Lines

The graph then plots two sets of five different ranges. These sets are broken down into Tangential lines (solid lines on our graphs) and Sagittal (dotted lines on our graphs). Sagittal lines are a pattern where the lines are oriented parallel to a line through the center of the image. Tangential (or Meridonial)  lines are tested where the lines are aligned perpendicular to a line through the center of the image.

From there, the Sagittal and Tangential tests are done in 5 sets, started at 10 lines per millimeter (lp/mm), all the way up to 50 lines per millimeter (lp/mm). To put this in layman’s terms, the higher lp/mm measure how well the lens resolves fine detail. So, higher MTF is better than lower, and less separation of the sagittal and tangential lines are better than a lot of separation. Please keep in mind this is a simple introduction to MTF charts, for a more scientific explanation, feel free to read this article.

 

Sony FE 24mm f/1.4 GM

From the moment this lens was released, Sony shooters have lost their usual understated decorum and declared loudly it was the best 24mm lens ever made in the history of the universe.

Lensrentals.com, 2019

At first glance, you may be a little underwhelmed by the MTF, but let me point out that 24mm f/1.4 lenses are almost always the most difficult primes to design and make and don’t generally have great MTF curves. So I think some comparisons are appropriate here.

Here is the Sony 24mm f/1.4 GM compared to the Canon 24mm f/1.4L Mk II, for example. (The 24mm is not the sharpest prime in Canon’s toolbox, but still, this is pretty much a butt whipping.)

Lensrentals.com, 2019

Even comparing the Sony to the Sigma 24mm f1.4 Art, the Sony is clearly better. This is the best 24mm lens we’ve tested.

Lensrentals.com, 2019

Just for a reality check, though, let’s remember the Canon is a pretty old design, and the Sigma, while not quite that old, was one of the first Art lenses. There has been a lot of improvement in lens design in the last few years, especially with regards to aspheric elements. For that reason, I would like to compare the new Sony to a new 24mm, but really there aren’t any. I did a comparison with the Sigma 28mm Art instead, which is a recent design. Let’s remember, though, that a 28mm lens is expected to be significantly better than a 24mm lens, because of optics and stuff.

Lensrentals.com, 2019

The Sigma is better, but I would call it ‘the difference between a great 24mm and a great 28mm better’. And to be really clear, the Sigma 28mm Art and Zeiss 28mm Otus are the best wide-angles, period. Overall, I have to say the Sony 24mm f1.4 GM is the best 24mm made right now and really a world-class optic. I must also point out that the price of the GM is lower than the Canon and about the same as the Sigma. No Sony Price Penalty here; this is a great lens at a reasonable price.

Sony 35mm f/1.8 

Next up is the new Sony 35mm f/1.8. For an f/1.8 prime, it’s what I call ‘fully priced’ at $750, but if it’s exceptionally good, that wouldn’t be a ridiculous price.

Lensrentals.com, 2019

At a glance, that is obviously a pretty good MTF chart, but let’s do some comparisons again. First up we’ll compare it to the Canon 35mm f/2 (and remember for MTF f/2 is an advantage over f/1.8). The Canon has a lower price, but the Sony is better at f/1.8 than the Canon is at f/2.

Lensrentals.com, 2019

For the next comparison, we’ll match the Sony 35mm to one of my favorite bargain lenses, the Tamron 35mm f/1.8 VC. Again, the Sony lens is clearly better.

Lensrentals.com, 2019

Like the 24mm, the Sony 35mm f/1.8 is exceptionally good. There’s no question that Sony has been cranking out one excellent lens after another lately, and this is coming from someone who ravaged the first, and many of the second, generation Sony FE lenses.

Speaking of first-generation FE lenses I despise (nice segue, eh?) let’s compare the f/1.8 with the Sony 35mm f1.4 ZA, the lens that probably sold more Canon-to-Sony FE adapters than any other. Sure, f/1.8 has an MTF advantage over f/1.4. But what you have here is a clearly superior $700 lens kicking the crap out of an inferior $1,500 lens. Also please realize if you leave a comment about how awesome your 35mm ZA is, we will all realize you mean ‘because I don’t have to use an Instagram filter to smooth my skin before I post my 800-pixel selfies’.

Lensrentals.com, 2019

Tamron 35mm f1.4 SP Di USD

OK, well so far, we’ve seen Sony kick the crap out of the competition (even when the competition is Sony), but it’s time to look at the lens I expected to be ‘pretty good at an excellent price’. The Tamron wins at most initials in the name, which I know is important to them, but other than that I expected this portion of the post to be about ‘worth the money’.

Lensrentals.com, 2019

What I got, though, was DAMN THAT’S GOOD! Great center sharpness, maintains sharpness well out to the edges, very little separation between sagittal and tangential lines. So I put up a quick comparison to the excellent Canon 35mm f1.4L Mk II lens. The $900 Tamron is clearly a bit better than the $1,500 Canon, which makes it better than the Nikon 35mm f1.4 G or Sigma 35mm f1.4 Art.

 

Lensrentals.com, 2019

Since I’d just sung the praises of the Sony 35mm f/1.8 lens, I decided I’d compare those two, even though the Tamron isn’t available in FE mount. As always, the f/1.8 lens has an advantage over the f/1.4 lens. Despite that advantage, it’s absolutely a draw in the center, but the Tamron is a bit better in the outer half of the image. So move over Sony, you were the 35mm king for about a day and a half; the time it took to run the Tamron tests.

Lensrentals.com, 2019

 

Roger’s Conclusions

As always, what I present you is just resolution testing. I don’t check the bokeh, how well it autofocuses, or anything else that really matters. Just resolution.

As is so often the case, my expectations were, uhm, less correct than they might have been. I expected the Tamron to be a nice lens at a good price. Instead, it is, for the moment, optically the best 35mm lens you can get, and at a price that should make you want to get it.

I thought the Sony 35mm would be better than the old 35mm f/1.4 ZA lens, mostly because that bar was set so low. It was better than that, it’s a superb little lens. Even though it sets new price highs for an f/1.8 prime, I’d definitely say it’s worth the money.

The Sony 24mm f/1.4 GM was as expected. It’s the best 24mm on the market for any brand and it’s priced reasonably for what it is.

Roger’s Speculusions

Yes, I made up that word since I’m concluding the conclusions with some speculations. Feel free to use it, though, I think it’s a great word.

For the last 2 years or so, we’ve been seeing a number of lens manufacturers make some amazing jumps in image quality. Sigma’s 28mm and 40mm Art lenses are far better than the older 24mm and 35mm Arts. It seems every Sony lens made recently is leaps and bounds better than what they turned out a few years ago. Tamron is suddenly tossing out world-class lenses. (I’m not going to bring Canon R and Nikon Z lenses into the discussion because of different mounts.)

We know some strides have been made in creating better and more complex aspheric lenses in larger sizes and with more accuracy. I would assume the improvements in aspherics are also reflected in more accurate shaping and polishing of non-aspheric glass. And I know that there have been strides made in optomechanics; placing the elements more accurately and refining how to adjust those elements for the best optical quality.

The bottom line is that you can generally be fairly sure, at this moment in time, that a lens designed more recently is going to be optically superior to one designed a decade or more ago. In 2010 we were all waiting for the next sensor with higher resolution. Those sensor resolution jumps seem to be slowing down now; but perhaps lens resolution jumps are going to take their place.

 

Roger Cicala and Aaron Closz

Lenrentals.com

September, 2019

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 Geek Articles
  • Because I don’t have data on the RF 35mm f1.8.

  • Refurb7

    Why not compare the new Sony FE 35/1.8 to the new Canon RF 35/1.8, instead of to the old Canon EF 35/2?

  • CameraCrazy

    utterly nonsensical. “microcontrast” (image fidelity) is low-gain SNR inter-tonal detail that adds dimensionality to any and all images. Also of course a visual aesthetic.
    Signal SNR (low-gain in this case) is both “scientific” and empirically palpable
    ……Maybe you should consider putting a true Monochrome camera on the bench and seeing for yourself the low-gain light that makes its way to the sensor with the removal of the CFA (color filter array)

  • Michael, “microcontrast” is like “organic”. It originally had a scientific meaning (high MTF at higher frequencies) but now has become a poorly defined term that means very different things to different people. Using the original, scientific, definition, yes we do, the 40 and 50 lp/mm data are microcontrast.

    That doesn’t mean we’re detecting what various internet experts claim as their definition of microcontrast.

  • bdbender4

    I understand about needing the new test mounts. However, if I may indulge in a little speculusionism, the Nikon Z system will emerge as the best compromise between weight, size, and MTF. It’s gotta, because it’s the system I went to late last year. 😉 I would expect the Canon R system lenses to knock MTF stuff outa the park, but look at the size and weight and prices. Tsk, tsk.

    Kidding aside, I have the Z 50mm f/1.8 and 24-70 f/2.8 and they are very nice. The f/4 24-70 is no slouch, either. In keeping with the general theme of this thread, there seem to be a lot of nice lenses out there these days, in every system.

  • Michael Hickey

    Slightly off topic…..do you ever examine for micro-contrast performance? And can you tell how well a lens performs with micro-contrast by looking at the MTF?

  • Neil P

    Does this mean that an APS-C camera system is automatically at a disadvantage due to the need for wider lenses? Or does the smaller imaging circle help out here?

  • Elena Hanak

    Thank you very much for the article. How Tamron 35mm 1.4 is compared to Milvus 35mm 1.4 ? Is there some MFT for Milvus? I cannot decide between these two… However, Milvus should be an artistic lens. That is what I need it for. Closeups, landscapes, nature. AF is not important. Which lens is better?

  • Stanislaw Zolczynski

    What about Leica

  • Jack Chan

    I had the Samyang and it was just as bad as my Sony Distagon 35/1.4
    Some have had good copies so it appears that sample variation is a problem with the Samyang 35/1.4 as well.

  • Jack Chan

    Too bad it’s for DSLRs only but Tamron is definitely putting more of their resources into mirrorless, going forward

  • Dave Hachey

    The number of excellent to outstanding optics from almost all manufacturers has increased in recent years, just read Roger’s blog posts here to follow the trends. Competition is a great thing. I agree, sharpness isn’t everything, but if you don’t have it you won’t have a great lens. I own a couple of ‘Big white lenses’ from Canon, and they have always been great. The improvements at the lower end of the focal length spectrum has come from a variety of factors (new optical glass formulae, new coating techniques, new lens manufacturing techniques, new electro-mechanical designs, etc.) BTW, I own a 85mm F1.4 lens (for Sony) that is so sharp I have to soften images in post to get an acceptable portrait. I still maintain that we are in a golden age for photography, at least with respect to gear, the vast majority of which is better than the person behind the lens.

  • Dave Hachey

    Really? About what?

  • Yair

    Thank you very much for the great article as always.
    My Copy of Milvus 25 1.4 is stunning , huge upgrade from the Sigma ART it replaced.
    very interesting to see MTF of it.

  • thepaulbrown

    Yes thanks Roger. I too would be curious even though none of them are on my radar as i’m still very happy using my Zeiss ZM 35mm 1.4 on my Sony.

  • thepaulbrown

    It’s at f/2.8 that’s why. In the article he makes reference to higher apertures resolving better by their nature

  • Chik Sum

    Thanks for the great work roger, but if this is a MTF machine version problem or aperture problem? coz when I just compared the numbers in the MTF charts in the old EF 24-70 F2.8L II @24mm it seems the center resolution was even better than this sony?

  • Sorry, I should have looked closer; Lensrentals hasn’t had much interest in it so it’s going to take a good while for me to access 10 copies.

  • Federico Ferreres

    A bad C.A. that doesn’t even go away after aggressive in camera CA kens auto correction, nor when stopped down to f11. Half a stop slower, with noticeable onion rings, the only thing good is what Roger measure, and the lens was designed for MTF tests. It has quite horrible Longitudinal CA as well, so any high contrast will visibly shift in hue. On the bokeh side, it looks nervous and run of the mill at best.

  • Kers

    Very nice to see Tamron made such a good lens!
    Another high end competitor has arrived.

  • Jack Chan

    It’s got fast AF and nice rendering but so many bad copies out there.
    People always want to defend their purchases.
    I’d rather take my lumps and then move on to something better except there wasn’t much better out there until the Sony FE 35/1.8 and Sigma Art FE 35/1.2

  • iKonOkLasT

    The Milvus 25 1.4. I’m aware you’ve already tested the Distagon 25 2.0.

  • CameraCrazy

    Dave, youre wrong. period

  • PJ Smith

    I agree to a point, because there have always been fantastic lenses at least for 25 years. Sure wide angle lenses have really improved in the last decade, but once you get to about 35mm and above there have been less important “leaps.” Nikon and Canon have always made excellent 50mm lenses and above, especially 200mm and above which are known as super-tele lenses of course. Although sharpness has increased in almost every type of lens, sharpness is not everything. Most people only care about how sharp a lens it, but that is a very stupid thing to only worry about. You can grab any old 300mm 2.8 or even 135mm f2 lens and they will be amazing, even 20 year old lenses. So people don’t know everything else a lens needs to be awesome! I however do know what to look at, besides sharpness.

  • PJ Smith

    Also it has all of the excellent qualities he did not test for, because I know I just bought one. It has excellent AF speed and reliability as well as very good bokeh and rendering. This lens really has it all and I although I knew it was sharper than my Nikon 35mm 1.4G, which I sold, I didn’t know it would match it in other area’s. I thought well I will buy the Tamron and see if I want to keep it or my Nikon 35mm. I quickly decided that it beat the Nikon in every way, except maybe build quality and finish. Sure the Tamron is made extremely well, but the Nikon is still made better in my opinion. I know most people do not care about that much, but I am a photojournalist and use my gear as tools, not expensive objects lol. However I didn’t have any real reason to doubt the Tamron but I guess well see in 5-10 years if it will hold up like I know the Nikon has and would continue to!

  • hyh

    Is this true for APS-C and m4/3 too – without converting to “equivalent” focal length? In other words, is designing 24mm and wider lenses for APS-C or m4/3 as difficult as for 24mm FF?

  • Nick Podrebarac

    Which is unfortunate, because it’s an awesome focal length for a prime lens, IMO, and a great companion for a 50mm.

  • 30 bad copies?

  • lwestfall

    Amazing these two new “light” 35mm lenses from Sony and Tamron barely beat even the venerable but beastly Sigma 40mm f/1.4 in the center, although the 40mm is sharper in the mid and outer parts of the frame.

    It would also be nice to include the Samyang AF FE 35mm f/1.4 for comparison.

    Thanks again for all your great work!

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