Just MTF Charts

Just MTF Charts: Perspective Control Lenses

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Published April 29, 2019
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I had a little hesitation about whether we should post these. Most people considering a tilt-shift aren’t thinking ‘I want the absolute best sharpness.” Plus what we show is the MTF without the lens tilted or shifted, both of which will affect the resolution to some degree, but you’re probably using them tilted and shifted. And finally, because tilt-shifts aren’t mainstream we don’t have 10-copy data for most. Generally, we have 5 or 7 copies tested, although we do have 10 copies for most of the Canon brand.

On the other hand, there really is no resolution data out there for Tilt-shift lenses, and no MTF charts. So I’m going to go ahead and post what we have.

Again, this is MTF with the lens in ‘straight-up’ position, neither tilted nor shifted. Some playing around we did with a few lenses shows the MTF drops pretty significantly with significant tilting or shifting. Also remember, with these lenses we’re comparing some designed 30 years ago with some designed in the last few years. The difference is pretty apparent.

 

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.

 

Canon Tilt-Shift Lenses

Canon TS-E 17mm f4L

Lensrentals.com, 2019

Canon TS-E 24mm f3.5L II

Lensrentals.com, 2019

Canon TS-E 45mm f2.8

Lensrentals.com, 2019

Canon TS-E 50mm f2.8L Macro

Lensrentals.com, 2019

Canon TS-E 90mm f2.8

Lensrentals.com, 2019

Canon TS-E 90mm f2.8L Macro

Lensrentals.com, 2019

Canon TS-E 135mm f4L

Lensrentals.com, 2019

Nikon PC-E Lenses

PC-E Nikkor 19mm f4E ED

Lensrentals.com, 2019

PC-E Nikkor 24mm f3.5 ED

Lensrentals.com, 2019

Nikon PC-E 45mm f2.8 ED

Lensrentals.com, 2019

PC-E Micro-Nikkor 85mm f2.8D

Lensrentals.com, 2019

Schneider Super-Angulon and Makro-Symmar

Schneider 28mm f2.8 Super Angulon

Lensrentals.com, 2019

Schneider 50mm f2.8 TS Super Angulon

Lensrentals.com, 2019

Schneider 90mm f4.5 Makro-Symmar

Lensrentals.com, 2019

Rokinon

Rokinon-Samyang 24mm f3.5 TS

Lensrentals.com, 2019

Roger Cicala, Aaron Closz, and Brandon Dube

Lensrentals.com

April, 2019

Addendum: The Digital Picture is hosting the MTF charts on their comparison tool, putting them up as we publish them here. It’s a great way to compare two lenses for the one or two of you who like to do that. The Canon and Zeiss primes are already up, the Sigma should be added by tomorrow.

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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  • MSC

    For most users who are using these lenses at small apertures, I am not sure how useful are mtf charts measuring performance at maximum apertures. What matters to me is how they perform at f8 or f11, which is where I would mostly be using them for landscape photography.

  • Andreas Martin

    Excellent test. Highly appreciated. Leica just recently added more APO lenses for their SL2 lineup. If I did get it right they tested them up to 60 lp/mm and they were even then in a 0,9 range. That would justify almost any price… Did you ever test any of the APO Leicas? The chief optics developer claims the 35mm is their best/masterpiece.

  • preston

    Ok, thanks for giving that other example. You’ve confirmed that sensibility of comparisons isn’t of value to you. By the way, Canon also makes a super sharp 135mm f/2.0 that is less than half the cost of the 135mm ts-e, so obviously they are different animals.

  • Franz Graphstill

    Why not? Both are 135mm lenses. I could use either to shoot at f/5.6 with zero tilt and zero shift and manual focus.

    Sure, there are things that one can do which the other can’t – the tilt/shift can’t reach f/1.8; and the 135GM can’t tilt or shift (well, not intentionally…).

    I can compare an 18 wheeler with a Tesla if I want – both can be used to take a passenger from A to B 🙂

  • preston

    Are you seriously comparing at manual focus only f/4 tilt-shift lens to an autofocus f/1.8 lens?

  • GuyWith

    Yes that Is theone

  • Hunter45

    Was that a “PC-E Nikkor 19mm f4E ED”?

  • GuyWith

    Having read and listened to lots of cinematographer interviews, very few have said that sharpness is a priority, and here in 2019, many of them still use diffusion filters to buff off some of that edge. They’re more interested in color, beautiful flare behavior, and overall “look.”

    Do you guys have any secret tests programmed in OLAF that might reveal why optics from Angenieux. Cooke, and Zeiss, for instance, are so beloved? I have read that it might be the way aberrations are balanced against one another which gives them their cinematic quality.

  • GuyWith

    After I shot with a 19mm Nikkor from LensRentals I had to go home and lie down till my head stopped spinning because the images were so perfectly sharp and lacking in geometric distortion. All my buildings looked like cardboard cutouts made by a 300-foot tall child.

  • Maksim Medushkin

    I was under impression that Cine Sigmas should be kinda like still Sigmas, Zeiss CP.3 should be like Milvus and Canon is Canon. So, even they are most commonly used, we all have expectations from them, like what you said yourself for Rokinons. But for Tokinas who knows what to expect at all? It is the most interesting! Just a point of view, no insistance meant or anything.

  • I’ll bet you $1 you’re surprised by some of the Canon, Zeiss, and Sigmas. In general, I start with most commonly used, try to set the standard sort of.

  • Maksim Medushkin

    That is great! But please start from those that have no still analogs. Everyone knows what to expect from Canons, Zeiss and Sigmas. But Angineaux for instance doesn’t even publish computer simulated MTF as well as Tokina and Fujinon.

  • Actually for most of the prime Cine lenses we’ll have 10 copies, although not all. Micro 4/3 MTFs are next, then the Cine’s will start.

  • Maksim Medushkin

    Thanks for your charts Roger.
    Do you consider measuring MTF of Cine lenses? I understand that it can’t be 10 copies, but it would be very interesting to have even a basic idea of how Angineaux, Fujinon ot Tokina Cinema actually perform.

  • Samuel Chia

    Well, not too long ago I had to put in 4 mils worth of correction for my EOS 35mm f/1.4 II. I’m not at all surprised that a Sigma might need the same. If this is out of Canon and Sigma’s spec, people can come to their own conclusions 🙂

  • Brandon Dube

    I’m not making any statement about anyone’s mount construction, except that 4 mil on Sigma’s lens bayonets is way too much and there must be a measurement error.

    Silicon Nitride bearings at the tightest tolerance are likely too expensive for Sony to choose – the last time I ordered some of those they were about $10/ea. I can’t imagine that that number will go below $1/pc at volume which is probably way outside the cost target Sony places on those components.

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