Just MTF Charts

Just the MTF Charts: Micro 4/3 Lenses

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Published May 6, 2019
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Not a lot to say specifically about the m4/3 lenses except please don’t ask why your favorite isn’t on here; this is all I’ve got. Some of the newer m4/3 have linear electronic focusing which can’t be tested on the bench without a specialized, expensive mount and we don’t have one. Even for the ones I have here, many don’t have 10 copies. Micro 4/3 doesn’t rent as much as it used to and we don’t have the kind of stock that we do in other mounts.

 

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.

 

Olympus

Olympus M. Zuiko 12mm f/2.o

Lensrentals.com, 2019

Olympus M. Zuiko 17mm f1.2 PRO

Lensrentals.com, 2019

Olympus M. Zuiko 17mm f1.8

Lensrentals.com, 2019

Olympus M. Zuiko 25mm f1.2 Pro

Lensrentals.com, 2019

Olympus M. Zuiko 25mm f1.8

Lensrentals.com, 2019

Olympus M. Zuiko 45mm ED f1.2 Pro

Lensrentals.com, 2019

Olympus M. Zuiko 45mm f1.8

Lensrentals.com, 2019

Olympus M. Zuiko 75mm f1.8

Lensrentals.com, 2019

 

Panasonic

Panasonic DG Summilux ASPH 25mm f1.4

Lensrentals.com, 2019

Panasonic-Leica 42.5 Noctitron f1.2 

Lensrentals.com, 2019

Panasonic Lumix 42.5mm f1.7 OIS

Lensrentals.com, 2019

Panasonic-Leica DG Macro OIS 45mm f2.8

Lensrentals.com, 2019

Voigtlander

25mm f0.95 Type II

Lensrentals.com, 2019

42.5 f0.95 Aspherical

Lensrentals.com, 2019

 

For a look at all the Just MTF Articles we’ve done so far, be sure to check them out here

 

Roger Cicala, Aaron Closz, and Brandon Dube

Lensrentals.com

May 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.

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  • Impulse_Vigil

    Totally, I’m actually looking to pair and/or replace some of my M4/3 gear with a larger format system (specially for the wides & UWAs where M4/3 doesn’t really have much of a size advantage), but that Oly 75mm is one of the last M4/3 lenses I’d ever let go.

    It’s fantastic for concerts with a really small body like the GX850, security never bats an eye, heck it’s a combo I often carry alongside a larger body/lenses… I end up using it for landscapes as much as portraits.

  • Eduardo Vidarte Charola

    Sorry , i can’t do conclusions with this graphics , I AM not a expert . Please, what are your conclusions about the Olympus 17 mm 1.8 ? In other of your test , You talk the 45 mm 1.8 of the same Olympus serie are very Good . In this case , the 17 mm 1.8 is similar in good results than the other brother in this Olympus serie 1.8 ‘s ?

  • Hank Roest

    And now the Sigma 56/1.4!

  • Maksim Medushkin

    Thnx. Correct in general is all I needed to hear to know I am not missing something important here.

  • Nope. Because I’m not willing to argue with fanboys for hours. You’re correct in general, but I’m to old for the inevitable hours of ‘cases where it’s not so’ discussions, nor the arguments about equivalent f-stops, etc. So I just go with ‘compare the sensor you shoot with to the sensor you shoot with’ and get out of the way. Which is what I will do here.

  • Maksim Medushkin

    But could you comment on my suggestion that 40 lp/mm on MFT is equivalentish to 30lp/mm and 20lp/mm on full frame?

  • Taki Tsonis

    Any particular reason why my comment from 3 days ago is still awaiting approval?

  • AF

    I own it and love it but find the AF lacking for sports. Shame because its speed and reach makes it a natural fit for sports but it just can’t keep up. With the same settings the 40-150 Pro trounces it. Still, great lens for portraits.

  • tripper

    Indeed, it does stand out. I actually bought it after lusting for it for years. And while very sharp and gorgeously made (I was very seriously impressed by the feel and mechanical quality), I was disappointed with the bokeh. A lot more than I ever thought I could, probably because it shows it ugly head in situations where I would like to use this lens the most. It really made me appreciate what Olympus did with the 25 and 45mm PRO primes. Their rendering is just a lot better.

  • Shlomo Levi

    main problem IMHO that this data should be official and publish by manufacturer bu demand. but modern marketing strategy is speak about feeelings not real data. i think that consumer behavior may change if real data will published.

  • It’s almost wort owning an mft just for the 75. Such a wonderful little lens.

  • Niko PetrHead

    OK thanks!

  • Andreas Werle

    Not so unusual. It can also be seen in case of the Leica Apo-Macro Elmarit R 100mm 2.8. Thanks for the explanation!

  • Brandon Dube

    Why must the lens be best in the center? That’s a common outcome, but there is nothing that says it must be so. The manufacture’s charts for both lenses have their peak performance away from center, too.

  • munotika

    Thanks!

  • It is, but it’s very time consuming and time is something I don’t have enough of.

  • Everything it tested wide open.

  • munotika

    At what aperture are these measurements done, wide open or at it’s best aperture (mostly f/2 to f/4 for MFT, considering diffraction limits as well)? Thanks for this comprehensive testing!

  • Deanaaargh

    Thank Roger for your reply that makes sense, it just seemed odd that it occurred with two f/1.2 lenses from the same manufacturer.

    I have enjoyed these MTF roundups so far. One group I would be interested to see the results is for the Macros. I recall reading in your OLAF methodology that testing was done at infinity focus. Is it possible with your system to determine MTF at 1:1 or even 1:4 reproduction?

  • These are unadjusted, as tested on the bench. You get to make your own extrapolations from there 🙂

  • Niko PetrHead

    Just to be sure… The frequency might have to be adjusted relative to the format?
    Or do the 50lp/mm here represent the same kind of fine details (100lp/mm actually) as the 50lp/mm in a randomly chosen 35.8 x 23.9mm other format?

  • OK, center sharpness. Remember we test each lens automatically, placing it and then rotating it 4 times so we get the MTF in all quadrants.

    A lot of lenses have the ‘optical center’ just a tiny bit away from the ‘geometric center’. If the optical center (sharpest part) is 1mm away from the geographic center you’d never notice it in a photograph. But the bench is more sensitive and when it rotates, at every rotation the MTF is highest 1mm away from center.

    So basically it’s a testing artifact that shows up with some lenses; not just Olympus f1.2s but it certainly does with them. We could carefully readjust for optical center with each pass of each lens, but that would add, literally, a day to the time it takes to test. The main reason we can do this amount of testing is that it’s automated.

  • That has a lot to do with edge drop-off, the center is a testing artifact and explained above.

  • I’m guessing on the m4/3 demand, but I think part if it is the lenses are less expensive, so less demand to rent. There’s a floor on rental cost: it costs just as much to clean, test, and inspect a $300 lens as a $3,000 lens, so rental prices are less attractive.

    There also used to be a greater demand for m4/3 photo lenses for video work, this has slacked off in the last 18 months or so, with an increase in m4/3 video lenses like Veydras.

    Finally, we see more rental when a lens first releases; people want to try before buying. So it’s normal that 6 months after release demand has dropped. There haven’t been as many new releases in the last year.

  • On the f/3.5 it wasn’t. The automation filled in data for the f/3.5 lens and I was lazy and didn’t check. I’ll respond to the other part after I fix that graph.

  • Thank you! Our graphics program lets us lazily type in something like “Olympus 12mm’ and then fills in the rest and sometimes it screws up and I don’t pay attention. The results are for the 12mm f/2.0 lens and I’ll get the graph corrected shortly. My bad.

  • J.L. Williams

    Re the 1.2s, I’m going to guess field curvature… there was more about it in Roger’s “Fabulous 40s” article…

  • J.L. Williams

    On the very first item, the subhead references the Olympus 12mm f/2, but the title on the chart says Olympus 12mm f/3.5 macro. Which is correct? Not trying to play “gotcha,” just want to make sure there isn’t an Olympus lens I’ve overlooked…

    (Can’t help wondering why M4/3 lenses don’t rent so much anymore… is it because most people who use them have just gone ahead and bought them, since none of them are very expensive? Or is everybody madly switching to Simplex format just like Hogan said they would?)

  • Deanaaargh

    Thanks for the post.
    What exactly is going on with the Olympus f/1.2 lenses seeming to be sharpest (at 10, 20,30 lp/mm) a little bit away from center? I don’t remember seeing this in any of the other lenses you have tested.
    I am also a little bit curious why the 12mm lens was tested at f/3.5.

  • Andreas Werle

    Hi Roger!
    thanks for the Data about Micro 4/3-Lenses. I think especially the 75 mm Zuiko is very nice, reasonable price and super performance.
    Greetings Andy

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