Just MTF Charts

Just the Cinema Lens MTF Charts: Xeen and Schneider

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Published May 20, 2019
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Xeen MTF Tests

We’ve completed the MTF postings for all of the photo prime lenses. Now we’re going to start with the Cinema primes. For a lot of those that also have a photo version, the optics should be identical. That’s not always the case, however. Plus, the people interested in Cinema lenses aren’t usually the ones interested in photo lenses, so it’s worth posting the cinema version, if only to make them easier to find.

As I’ve mentioned before, we often don’t have 10 copies of the cinema version of a lens, so these are the average for whatever copies we were able to divert from rental long enough to test. The graph should show you how many copies were tested for each lens.

I’m not doing them in any particular order, just a couple of brands at a time. We’ll get to the others soon.

 

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.

 

Xeen Cinema Lenses

Just in case you are wondering, we test these in the different mounts and there is no MTF difference. If you weren’t wondering, carry on.

Xeen 14mm T3.1

Lensrentals.com, 2019

Xeen 24mm T1.5

Lensrentals.com, 2019

Xeen 35mm T1.5

Lensrentals.com, 2019

Xeen 50mm T1.5

Lensrentals.com, 2019

Xeen 85mm T1.5

Lensrentals.com, 2019

Xeen 135mm T2.2

Lensrentals.com, 2019

Schneider Cinema Lenses

Sorry, there are fewer copies here and not the complete set, but these are all I have.

Xenon FF

Xenon Prime XN 35mm T2.1

Lensrentals.com, 2019

Xenon Prime XN 50mm T2.1

Lensrentals.com, 2019

Xenon Prime XN 75mm T2.1

Lensrentals.com, 2019

Xenon Prime XN 100mm T2.1

Lensrentals.com, 2019

Cine-Xenar III

The Cine-Xenar III series is designed for Super 35mm and crop sensor cameras, so they don’t cover the full 20mm off-axis.

Cine Xenar III 25mm T2.2

Lensrentals.com, 2019

Cine Xenar III 35mm T2.1

Lensrentals.com, 2019

Cine Xenar III 50mm T2.0

Lensrentals.com, 2019

Cine Xenar III 75mm T2.0

Lensrentals.com, 2019

Cine Xenar III 95mm T2.0

Lensrentals.com, 2019

 

Roger Cicala, Aaron Closz and Brandon Dube

Lenrentals.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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Posted in Just MTF Charts
  • Ayoh

    This is not true. Laser spots size is typically 80um or larger and the melt pool width is close to double that. Don’t know what printers you have access to but those specs are not really available in any commercial system. Regardless the surface finish is too poor (see other comment)

  • Ayoh

    No way you could directly print the mount with the required accuracy and surface roughness (i work with SLM machines). All functional surfaces would need to be post machined with defeats the purpose of printing to near net-shape in the first place. Might be easier to take the flange from a camera and fasten it to a machined boss or similar if that saves cost. Would not require machining of the complex flange

  • Dragon

    That 135mm Samyang is pretty impressive.

  • I don’t have the mounts for them for the machine. Mounts are $10k or so to get made. I also don’t have a spare $10k.

  • T&L

    Roger, thanks for the great job.
    Would you be interested to run MTF for medium format lenses of XCD and GFX mount?

  • Carleton, from a resolution (MTF) standpoint, they aren’t great, but they have a ‘look’ many cinematographers seem to like. Photo people have to remember that until recently, cinema was being shot on the equivalent of 4 megapixel cameras, resolution has only recently (with 4k and 8k cinema) become really important to them.

  • Carleton Foxx

    The Schneider mtf curves seem ok but not spectacular to my very untrained eye, is there anything about them that justifies their high prices?

  • See above. It’s $8,000 to $10,000 per mount. I promise anyone buys me the mount, I’ll test the lenses. Just email me your check or I can arrange to take paypal. And no, I won’t do Kickstarter because I always deliver what I promise so that seems an inappropriate venue.

  • Andreas Werle

    No Leica M/SL Charts?

  • Daniel Eggerstorfer

    Thanks for your nice MTF round up.
    For comparisonsake, would it be possible to give us the f-stops in the Cine graphs?

  • Brandon Dube

    None of the vendors are all that different for their MTF charts, with the exception of Irix which uses extremely strong spectral weighting to inflate their curves. Everyone else is trying, honestly, to emulate a realistic spectrum and their models won’t be that different.

  • Brandon Dube

    If you buy the mount, we’ll do the testing.

  • John Dillworth

    “We’ve completed the MTF postings for all of the photo prime lenses” Have you? Funny, I didn’t see the Fujifilm lenses. I’ve rented them from you……so I know you have them. Fujifilm renters might not be a big part of your business but they are driving a disproportionate amount of the mirrorless conversation. How about some love for us?

  • Alan

    It’s probably closer to 20 micron feature size/precision. The spot size for the laser and layer height is better than 20 micron, but I think it’s safer to say 20 micron.

  • We don’t. We basically take a mount and scan it to generate the CAD files and get a mount CNC machined. I’m not familiar with the accuracy of 3D mental printers, but we need on the order of 10 mcg or better.

  • Alan

    I’ve seen your 2013 article on adapters, but it would just be interesting to see if there is *something* that Pentax does well. Pentax has the most accurate ISO ratings, so it’d be interesting if they are more optimistic/less optimistic than others on MTF charts. Out of curiosity, do you have CAD files for a K-mount for OLAF? I do have access to metal 3D printers.

  • Well, computed MTFs are why we do this, because idealized computer with unknown variables (want a pretty MTF? Plug a narrow light range into the program.) But no, we don’t have a K mount, I’m afraid, and MTF testing on adapters is iffy at best.

  • Alan

    Any chance we can get something like a Pentax D FA* 70-200 or 50 on the test bench? I know what you’ve written about adapters but it would be interesting to see if a Pentax on a K to E mount adapter performs well. The 70-200 seems to have good symmetry on the official MTF simulations.

  • DrJon

    BTW did you ever see the long post (or the slightly shorter version) I wrote on the RX100 when you got one, as that disappeared down a hole too and was in part aimed at you? (In “What to Look at to Find the Best Compact Camera for You”.)

  • We’re sending him the new charts as we post here, he’s taken all the old data down. Right now they have all the photo primes up. I assume he’s going to add the cinema primes to it.

  • Thanks Roger & Jon, I knew that Bryan had some older charts, but I wasn’t ware he has access to the latest LR data.
    Anyway, Roger, if you’d like to have something modern built for LR – please let me know, it could be a fun project 🙂

  • Sorry DrJon, the spam has been horrid lately and the WordPress spam filters are very all-or-none. I think this is the link you were going to post. https://www.the-digital-picture.com/Reviews/MTF.aspx?Lens=244&FLI=0&LensComp=0&FLIComp=0

  • DrJon

    My reply giving the link to the page at The-Digital-Picture seems to have got nuked by a spam filter, but there is a page there where you can do that… (For LensRentals MTF plots.)

  • Thanks, Andy. I”ll get that graph fixed.

  • Andreas Werle

    The Sony 24 seems to be a great lense, did google the review. Thanks for that!
    Canon Rumors expect BTW an new 24/1.4 RF this year. We will see how it performs and guess Roger will show us some beautiful MTF-Charts!

  • Time to build a comparison web app?

  • Wide fast lenses are difficult to make. The Sony GM 24 1.4 is the first one that is truly fantastic, and was 70% of the reason I just switched from Canon to Sony. Previously, the go-to option for astrophoto (which needs even sharpness across the frame more than absolute center sharpness) was to buy a couple Roki 24s and keep the best one. Also, in my experience, the Roki 24 sharpens quite quickly as it stops down, so the f/2 performance is /much/ better than the f/1.4 performance. The Sigma 24 1.4 has outrageous coma and tends to optically misalign quite easy, so most astrophotographers don’t consider it.

    I posted this comment with a link to an astrophoto-themed Sony 24 review on SLRLounge, and it is awaiting moderation. You can find the review yourself by googling it.

  • Andreas Werle

    Thanks Roger for showing the MTF-Charts to us.
    There is an error in case of the Schneider Cine-Xenar III 50mm T2.0 PL, it reads T50 instead T2.0. Again the results for the Xeen 135 mm are impressive and different from the others. BTW, i was looking through different brands and my impression is, that fast 24mm lenses are somewhat weak, even the Sigma is not outstanding. Wondering, whether there is anything special with this focal length, but of course this cannot be. 🙂
    Greetings Andy

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