Ultimate Guide to Flange Focal Distance

UPDATED: February 4, 2022 / ORIGINAL: March 18, 2016

Flange Focal Distance – also known as Flange Distance or Flange Depth – is the distance from the camera’s mounting flange to the film or sensor plane. Another way to look at this is Flange Focal Distance refers to the distance the lens needs to be mounted from the film plane.


This distance varies between cameras and lens mounts which explains the depth (or thickness) of lens mount adapters. If you scan to the chart below you will see that Canon EF-mount has a Flange Focal Distance of 44mm and Sony E-mount has a Focal Distance of of 18mm.

44mm – 18mm = 26mm

This means that Canon EF to Sony E lens adapters need to be 26mm thick in order to make up that difference so that the lens will mount the proper distance from the film or sensor plane which allows the full range of focus from infinity to the minimum focus distance.

Most lens mount adapters are constructed to be very slightly thinner than this distance which allows lenses to focus past infinity. While this may be frustrating to Leica lens users who are used to a hard-stop at infinity – it beats the alternative that if a lens mount adapter is even slightly too long – the lens will not focus to infinity.

While lens mount adapters might look like extension tubes – they are not. There is no light light loss – they simply place the lens at the proper distance from the film plane or sensor.

The Flange Focal Distance of the lens must be greater than that of the camera body it is to be adapted to in order to allow room for the adapter.

Simple math explains why it’s possible to make Canon EF lens to Sony E-mount body adapters but it’s NOT possible to make a Sony E-mount lens to Canon EF body adapter, because in order to mount a Sony E-Mount lens on an Canon EF body, the adapter would need to be a NEGATIVE 26mm thick!

It should go without saying (yet I get this question every month) but E-mount to E-Mount Speedbooster adapters are also impossible because they would need to be ZERO MM thick…

Focal Flange Depth Chart

Lens Mount Flange Focal Distance Camera Type Camera Format
Pentax Q-mount 9.20 mm Mirrorless 1/2.3″ x 1/1.7″
D-mount 12.29 mm Cine 8mm
CS-mount 12.50 mm TV 1/4″, 1/3″, 1/2″
Nikon Z-mount 16.00 mm Mirrorless 24X36 mm / APS-C
DJI DL-mount 16.84 mm Mirrorless 24X36 mm / APS-C
Nikon 1-mount 17.00 mm Mirrorless Super 35
C-mount 17.526 mm Cine/TV 8mm, 16mm, 1/3″, 1/2″, 2/3″, 1″, 4/3″
Fujifilm X-mount 17.70 mm Mirrorless APS-C
Canon EF-M-mount 18.00 mm Mirrorless APS-C
Sony E-mount 18.00 mm Mirrorless 24X36 mm / APS-C
Hasselblad XCD mount 18.14 mm Mirrorless Medium Format 43.8×32.9 mm
Sony FZ-mount 19.00 mm Cine Super 35mm
Micro Four Thirds 19.25 mm Mirrorless 17.3 x 13 mm
Canon RF mount 20.00 mm Mirrorless 24X36 mm / APS-C
Leica L-mount 20.00 mm Mirrorless 24X36 mm / APS-C
JVC 1/3″ bayonet mount 25.00 mm TV 1/3″ 3-CCD
Samsung NX-mount 25.50 mm Mirrorless APS-C
Fujifilm G mount 26.7 mm Mirrorless Medium Format 43.8×32.9 mm
Pentax Auto 110 27.00 mm SLR 13X17 mm
RED ONE 27.30 mm Cine Cine
Leica M-mount 27.80 mm Mirrorless 24X36 mm
Nikonos 28 mm Underwater 24X36 mm
Leica M39 mount 28.80 mm Mirrorless 24X36 mm
Olympus PEN F 28.95 mm SLR 18×24 mm
Contax G-mount 29.00 mm Mirrorless 24X36 mm
Contax RF-mount 34.85 mm Mirrorless 24X36 mm
Nikon S-mount 34.85 mm Mirrorless 24X36 mm
1/2″ TV bayonet mount 35.74 mm TV 1/2″ 3-CCD
Minolta V-mount 36.00 mm SLR APS-H
Sony 1/2″ TV bayonet mount 38.00 mm TV 1/2″ 3-CCD
Olympus Four Thirds System 38.67 mm SLR 4/3″
Konica AR-mount 40.50 mm SLR 24X36 mm
Konica F-mount 40.50 mm SLR 24X36 mm
Canon FD-mount 42.00 mm SLR 24X36 mm
Canon FL-mount 42.00 mm SLR 24X36 mm
Fujica X-mount 43.50 mm SLR 24X36 mm
Minolta MC/MD mount 43.50 mm SLR 24X36 mm
Arri LPL 44.00 mm Cine 25.54×36.70 mm
Canon EF-mount 44.00 mm SLR 24X36 mm / APS-C
Pentaflex 44.00 mm Cine 16 mm
Praktica B-mount 44.00 mm SLR 24X36 mm
Sigma SA-mount 44.00 mm SLR 24X36 mm / APS-C
Minolta / Sony A-mount 44.50 mm SLR 24X36 mm / APS-C
Rollei / Voigtlander QBM 44.50 mm SLR 24X36 mm
Exakta 44.70 mm SLR 24X36 mm
M39x1 45.46 mm SLR 24X36 mm
M42 45.46 mm SLR 24X36 mm
Pentax K-mount 45.46 mm SLR/Mirrorless 24X36 mm
Contax C/Y-mount 45.50 mm SLR 24X36 mm
Kodak Retina DKL-mount 45.70 mm SLR 24X36 mm / 28X28mm
Voigtlander Bessamatic DKL 45.70 mm SLR 24X36 mm
Voigtlander Vitessa T DKL 45.70 mm Mirrorless 24X36 mm
Yashica MA-mount 45.80 mm SLR 24X36 mm
Olympus OM-mount 46.00 mm SLR 24X36 mm
Nikon F-mount 46.50 mm SLR 24X36 mm / APS-C
Leica R-mount 47.00 mm SLR 24X36 mm
KMZ Zenit DKL-mount 47.58 mm SLR 24X36 mm
B4 2/3″ TV bayonet mount 48.00 mm TV 2/3″ 3-CCD
Contax N-mount 48.00 mm SLR 24X36 mm
Arri B 52.00 mm Cine
Arri PL 52.00 mm Cine
Arri STD 52.00 mm Cine
Leica S-Mount 53.00 mm SLR 45×30 mm
T-mount 55.00 mm SLR 24X36 mm
YS mount 55.00 mm SLR 24X36 mm
Panavision PV-mount 57.15 mm Cine
Mamiya 645 63.30 mm SLR 6X4.5 cm
Contax 645 64.00 mm SLR 6X4.5 cm
Pentax 645 70.87 mm SLR 6X4.5 cm
Rollei SLX 74.00 mm SLR 6X6 cm
Pentacon Six 74.10 mm SLR 6X6 cm
Hasselblad 500 / 2000 74.90 mm SLR 6X6 cm
Hasselblad 1000F / 1600F 82.10 mm SLR 6X6 cm
Pentax 6X7 85.00 mm SLR 6X7 cm
Rollei SL66 102.80 mm SLR 6X6 cm
Mamiya RZ67 105.00 mm SLR 6X7 cm
Mamiya RB67 111.00 mm SLR 6X7 cm

Source: Wikipedia and Manufacturer Specs

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Ultimate Guide to Sony Lens Adapters

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144 thoughts on “Ultimate Guide to Flange Focal Distance”

  1. Pingback: Sony a99 II -vs- a7R II 42.4MP Showdown

      1. The only way would be to replace the e-mount ring with one from an x-mount lens and then hope everything lines up properly.

  2. how much depth of focus would you get if you used a 46.5mm flange depth lens with a 46mm flange depth camera with a 5mm adapter?

          1. But these filters are obviously more than 0.5mm, I was just wondering how big of a window there is between lens flange depth and camera flange depth where the lens is still usable?

          2. Are you asking about filters or adapters? The adapter in the example you gave WOULD need to be 0.5mm or thinner to maintain infinity focus.
            46.50mm – 46.00mm = 0.5mm adapter depth

            But a Canon EF to Sony E mount adapter should be 26mm thick.
            44.00mm – 18.00mm = 26mm adapter depth

            It’s simple math.
            Have a look at the illustration.

  3. Hi,I want to make my own mft-m42 adapter and print it 3d.I made the difference : 45.46 mm-19.25mm=26.21mm.It`s that the dimenssion of the total adaptor or just the middle section,without the m42 mount and mft mount?If you could respond,I would appreciate,thanks

    1. Assuming you mean M42 lens > MFT camera, your math is correct. HOWEVER you should trim at least .01 from the length. This will cause the adapter to focus past infinity. If you are even .001 too long you will not be able to focus to infinity. When it comes to adapters, it’s much better to be too short than too long.

      1. Yes they will.as long as a proper adapter is used (one that sits inside the K mount)
        Pentax designed the K mount to be backwardly compatible. Both M42 & the K mount have a flange distance of 45.46mm. With a proper adapter the flange of the M42 lens sits directly on the flange of the camera.

  4. sir, i am having a c mount on a beam splitter for my operating microscope.
    i want to attach a DSLR camera over the c mount for live surgical video recording. what options do i have in sony DSLR without vignetting and loss of quality for high definition recording??

      1. thanks for reply sir,
        then how to connect beam splitter to a DSLR??
        any mount or adapter available??
        thanks regards

        1. Apparently there are C-lens to Z-mount adapters from Kipon. Before buying I would suggest to rent a Z camera to try.

  5. Hi! I’m planning on building my own camera (I know, I know, bold project) and find that the flange focal distance is the biggest problem. I have a 50mm f.1,8 lens, as well as a M42-> EOS adapter. The adapter will work as the mount for the lens to my camera (making it an interchangeable-lens-camera). First of all – the problem is to measure the correct distance from my lens to the point where I will install my film roll and shutter. From the table, I understand the distance would be 45,46mm (am I right?). Second, it will be hard to INSTALL the film and shutter at the right distance. Well, I’ll cross that bridge when I get to it.

    My question is; if I install the film slightly off TOWARDS the lens, would I be unable to focus at all, or would I just eliminate the opportunity to focus at infinity and/or at a very close distance? And how far off would I have to be to not be able to get any focus at all?

    I’m hoping for a response, and just ask me to clear things up a bit more if my explanations were bad!

    Thanks in advance!

    1. If you are slightly too shallow the lens focuses past infinity which is not really a problem.

      If you are slightly too deep the lens won’t focus to infinity. Much bigger problem.

      1. Im reading this, because i have interesting problem – have my distagon 18mm 3.5 canon EF – i bought adapter for sony E, which is 25.55mm deep.
        Well problem is, that if i focus with distagon on infinity, im according to the numbers on the distagon at approx 3.5m.
        i was surprised how bad the quality is in corners, when i examined few photos, so i made a test with canon 5D mark II and sony A7C – in canon the corners and whole image is sharp even on f/3.5, on f/8 its simply zeiss quality corner to corner.
        And, the quality of the picture on A7C is horrible. Only good is the middle, corners are not even close to sharpness. At F/8 they are closing to F/3.5 on canon.
        So i think, that the adapter HAVE TO BE exact deep. If its closer, it is same problem as it is far.

        i have now one more adapter on the way, a bit cheaper so i will disasemble it and will try exact 26mm and make test photos.
        Or if anyone have some explanation – lets throw it on me

        1. Exact depth is not an issue. Precise flatness is.

          Which adapter did you buy? I don’t recommend buying the cheapest adapters since many of those are not perfectly flat from front to back which can throw off focus across the field of view. That might also happen if you try to shim an adapter to exactly 26mm. If you are not perfectly flat you essentially throw in an undesired ’tilt’ to the focus plane similar to a tilt/shift lens that’s not perfectly zero’ed out. Also, if you are even a fraction too long – you’ll lose infinity focus. This is why adapters are always a fraction ‘short’ of the actual difference in focal flange distance.

  6. I want to connect my Micro 4/3 lens to C-mount camera. The lens producer told me it’s impossible. But according to your article the lens flange focal distance should be greater than camera flange focal distance and it is indeed. So what’s the problem?

    1. It’s theoretically possible BUT you’d need someone to make an electronic adapter that was a mere 1.75mm thick (which is basically impossible) if you wanted to control the aperture. Given that C-mount is pretty much a “dead” lens mount…don’t hold your breath…

      1. Okay, that’s good news. I don’t want to control the aperture because the lens I want to use is a mirror lens (Tokina Reflex 300 mm f/6,3) with fixed aperture. Why you have said that adapter should be 1,75 mm thick? The MTF lens flange focal distance is 38,7 mm and C-mount flange focal distance is 17,526 mm. The difference bettween them shouldn’t be equal to adapter length? The problem is I haven’t seen such adapters yet…

        1. Nope. Flange Depth of Micro Four Thirds is 19.25mm so roughly 1.75mm.

          But once again, I don’t see anyone making C-mount lens adapters since there is not a sufficient market for them.

          1. Right. So the lens manufacturer gave me the wrong numbers. Thank you very much for the right ones. My colleagues have just designed (scetched) such adapter and we must manufacture one. Do you see some other disadvantages of connecting such lens to C-mount camera?

          2. Are you by any chance in possesion a knowledge about the possible spot size of this particular lens? I just heard that this kind of lenses (mirror ones) are “soft” so I assume that spot size is quite big…

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  9. Hi Brian!

    Thanks for this information. It really helped clarify things for me. I am looking to make some janky lomo adapters where I will be able to use Pentax Q lenses on a Micro Four Thirds camera. My plan is to epoxy a body cap and a rear lens cap together, then see what sort of visuals that results in. Based on your math, the focus quality is going to be terrible. But would it be in any way workable? Like in an artsy abstract sense? Either way, I’ll be shaving those caps down to as thin as possible now that I’ve read your info. I’m sure it will all turn out horrible in the end, but it’s a fun experiment for an uneducated pleeb like me.


    1. I would NOT advise that.

      You’d need to mount the lens 10.05mm INSIDE the camera. Forget about shaving the lens cap down – you need to cut a hole in the cap and mount the lens almost 1/2 inch inside the body.

      You’d risk damaging your sensor and even if all went well, the lens would not cover the M43 image sensor.

  10. Pingback: Sony a7R III -vs- a99 II 42.4MP Camera Showdown

  11. Hi I have a canon eos rebel t5i and i bought a 50mm cctv lens. I purchased a c mount adapter separately and found out that because of difference on focusing distances between Canon and 16mm sensors, it can focus on very close objects only (about 20-30 cm). Is there any c mount adapter or optimizer or any othee solution to make a 16mm cine operate normally on my canon camera? Although i like the macro focus, i would love to be able to use the camera cctv lens as originally intended. Thank you in advance for your answer.

    1. If you wish “to be able to use the camera cctv lens as originally intended”, you must select a body thinner than the camera it was designed for. Canon EF mount is too thick.

  12. hello interesting page here,but I have a Panasonic GX800(850) mft camera and an old Canon TV lens (c-mount) J8x11 but it; s hard to come to infinity..tried different option with Tele Lens converter set ON (in videomode), ..I saww some clips on Youtube with pretty good results but it doesnt infinite..is it a flange issue or worthless lens Im using?any tip is very welcome..thanks!

    1. Is it possible that it’s actually focusing past infinity? Lens mount adapters are generally slightly shorter than the required depth to make up for lens irregularities which means infinity focus is slight before the lens infinity marking.

  13. Hi Brian,

    You are missing Samsung NX Mini with flange distance of about 6mm.

    It is likely one of the best cameras to adapt C lenses. It is a bit tough because you have to short circuit 11th(with or without 2nd pin also) pin for the camera to fire. There’s a person on Ebay selling the adapter for 36-40$.

    It’s a shame Samsung stopped making them in 2014. It’s a great little 1″ sensor camera. Too bad it doesn’t have some of the modern features like peaking to make manual focusing easier.

  14. Konica AR lens converted into Canon EOS FF mount, so can I use this lens on Sony E FF with EF to E adapter, so lens will do work like normal lens, min. and infinity focus will do work well like original mount lens ? If not so what should I do to use this lens ?

  15. A Konica AR lens converted into Canon EOS FF mount, so can this lens be use on Sony E FF body with EF to E adapter, so lens will do work like normal lens like min. focus and infinity focus will do work like original mount lens that use with adapter ? If not so what should do with this lens to use on Sony E FF body ?

  16. Would a Leica M mount lens that protrudes a tad at the rear, and that is fine on a Sony E mount, be ok on a Fuji mirrorless mount? I see the FDs are 18mm and 17,7mm respectively. But I’m not quite sure what to conclude from that.

    The lens is an MS Optics Perar 35mm 3.5 II.

  17. Is it possible to adapt an OM manual lens to a Canon 6D body? Do Canon EOS 5D and Canon EOS 6D have the same flange focal distance? Thank you, FS

  18. Brian R Patterson

    I would like to mount a Schneider 240mm enlarger lens to a helicoid for use on my a7r3 – any idea how much distance would be needed- or the helicoil range – to position that optic from the mount for infinity focusing?

    1. Just like large format lenses, the general rule of thumb with enlarging lenses is that the front standard must be the focal length of the lens from the sensor for infinity focus. Not an absolute, but a very good starting point. Don’t forget to factor the 18mm focal flange distance into that measurement.

  19. I was wondering about this: “It should go without saying (yet I get this question every month) but E-mount to E-Mount Speedbooster adapters are also impossible because they would need to be ZERO MM thick…”
    Is that really so? I mean, focal length extenders are thingies that magnify the image on the sensor, yet they do focus to infinty while they are nowhere near zero length. So if it would be possible to make optics that reduce the image while moving the focus plane back, it would do the trick. I did no try to do any optics math, but it is not so evident to me that this would be completely impossible 🙂

    1. Teleconverters and Focal Reducers are not the same thing.

      Teleconverters ALWAYS push the lens mount farther away from the sensor as the expand the image image circle which results in

      Focal Reducers are designed to maintain the focal flange distance of the selected lens as the compress the image image circle (Fullframe > APS-C or Medium Format > Fullframe)

      Both use glass elements which can lead to image degradation. Recent advances in teleconverters such as FE teleconverters minimize degradation by employing an optical design of certain telephoto lenses specifically matched to the teleconverter.

      That is NOT the case with focal reducers which means they cause greater image degradation the higher quality teleconverters. Changing the math by increasing focal flange distance would result in considerably more degradation.

  20. SPEEDBOOSTERS are optical devices (i.e. they have glass elements) which mount between lens and body and give a wider field of view and an effectively faster maximum aperture. These are generally used to reduce or eliminate the crop factor when using a full-frame lens on a smaller-than-fullframe sensor. The thickness of the unit vs flange focal distance is inconsequential .. the optics handle the ‘distance conversion’ and are designed to focus the image on the target film plane. Some units are designed to focus a shorter-FFD lens on a longer FFD body.

    FOCAL LENGTH EXTENDERS are optical devices (they have glass) which mount between lens and body to reduce the field of view — to make a short lens act like a telephoto lens, and consequently lose a stop or two of brightness. These are usually not adapters — e.g. they’re used for cameral/lens combinations which already work together, but you want to be longer. Flange focal distance is not an issue because the optics in the unit [re]focus the image on the film plane.

    Neither type really has much to do with Flange Focal Distance as listed in these charts.

  21. Thanks, David!
    I would say speed boosters are the opposite of focal length extenders. An extender in effect magnifies the image, which also means the light spreads on a larger area, making the image dimmer, which means the effective aperture size is decreased. The booster reduces the image size, which results in a brighter image per area unit, or in other words a “larger aperture”.
    I was curious enough to study a bit more, and found a paper in the Metabones website: https://www.metabones.com/assets/a/stories/Speed%20Booster%20White%20Paper.pdf
    It explains well the optical principles of a speed booster. An interesting fact is that the distance of the adapted lens with booster from the sensor is less than the flange distance of the native mount. (See page 10) So indeed the booster thickness is not the same as the flange distance difference of the native and target system – it is shorter! (A plain adapter must have that length.) I guess the actual booster thickness depends on the optical formula, but in principle it acts as a positive lens. And using that optical principle the booster should have negative length (not zero), so the lens should be pushed inside the camera.
    I’m still wondering… what if we put a negative lens in between, so that the image would be forming farther away? Tried to draw a figure, it can be seen here: https://ilmari.smugmug.com/Other/Photo/n-589XKd/i-KjLxKFT/A
    I’m not claiming this would be practical or capable of good quality, as it should protrude into the camera, and it would be a much more complex design. But just in principle, not impossible, huh?

  22. Hi there and thx in advance for sharing your knowledge, i want to adapt a yashica yashinon 45mm 1.7 from a yashica electro 35 to my olympus micro 4/3 do you know the numbers for this adapter

    Also i have a Aires coral 4.5cm 1.5 i want to adapt to micro 4/3 do you know those numbers as well??

    thx in advance 🙂

    1. Yashica electro 35 is a fixed lens camera. The 45mm lens is fixed to the body and does not have an interchangeable lens mount.

      I’m not familiar with the second.

      1. Yeap i know i would have bought the adapters if they were available, some sellers on ebay for the yashica lens adapted to sony e mount and i have seen one guy that makes a Aires Camera adapters for sony full frame not for micro 4/3

  23. Chaitanya Rajarshi

    Hi, nice article.Thanks for sharing. What is the relation between flange focal distance and back focal distance? BFD will be always less than FFD, but how much?

    1. Back Focal Distance varies from lens to lens and does not factor into the calculations for lens adapters as the thickness of a lens adapter is purely dependent on the difference in Focal Flange Distance.

      Back Focal Distance is only less than Focal Flange Distance if the rear lens element extends behind the lens mount. Generally that is not the case.

  24. Jude Thaddeus Bautista

    Hi Brian,

    I am so grateful for this post. Based on your formula the Canon RF mount at 20mm can be adapted to the Sony E Mount – 18mm. Is this possible with the 2mm difference? I wonder why I haven’t seen any adapters out there yet.

    As a prospective Canon R5 user, I was considering the possibility of having either the Sony A7 III or A7S III or even the new A7c as a smaller more compact, full frame secondary body. BUT seems to only make sense if there was an RF to E-Mount lens adapter.

    Your much informed response is very much appreciated. Thank you in advance from the Philippines!

    Jude B

    1. In theory yes, but you only have 2mm in which to fit the electronics to transfer control of AF and aperture. Techart did this with their PRO Autofocus Adapter for Sony E-Mount Lens to Nikon Z-Mount Camera but that adapter gets lukewarm reviews which given the constraints in size is entirely understandable.

      Techart PRO Autofocus Adapter for Sony E-Mount Lens to Nikon Z-Mount Camera

      Adapting RF lenses adds another level of difficulty, since for reasons I can’t explain, Canon has chosen to stick with DSLR-era rotational stepping motors in their RF lenses rather than the much faster linear focus motors that Sony uses in their mirrorless lenses.

  25. Hi I have a canon rebel t3 and I want to put a old (90’s) Tamron lens on it so what adaptor would I need?

  26. I Actually don’t know I’ve never seen one like it. It is completely flat but I do have a old Tamron to canon adaptor that is a Bayonet type that was with the old camera

    1. Unfortunately the Canon Bayonet adapter won’t do you any good.
      Canon FD/FL lenses have a 42mm flange depth. Canon EF bodies have a 44mm focal flange distance.
      This mean an adapter would need to be a NEGATIVE 2mm thick. Which is what there are none.
      The good news is that it could be adapter to mirrorless – just not EOS camera bodies.

    1. Now this is guessing, but the Tamron may be an Adaptall system lens. In that case you might find from eBay or elsewhere an Adaptall mount for Contax/Yashica or some other type that can be adapted to EF.

  27. I just found an adaptor that will work perfectly for what I need but I won’t be able to change the aperture. What aperture will it be stuck at?

  28. It does have an aperture ring but for some reason the guy I’m purchasing it from said I won’t be able to change it

    1. I could be wrong, but I believe he’s referring to the fact that the aperture can’t be adjusted “in-camera.”

      It’s also possible given the era that it’s a preset lens rather than auto-aperture which means you focus wide open then stop down to shoot. If that’s the case, you can leave it stopped down.

  29. What’s a flange focal distance in BlackMagic Design Camera 2.5 K w PL-mount? I’m trying PL-Zeiss lenses from ARRI SR2, they don focus in infinity (while they wide open). Please advise.

      1. Ted Ciesielski , Man with the movie camera

        Thanks Brain, but there are two formats with PL-mount: S35mm and S16mm.
        BlackMagic Cinema with MFT sensor (15.81×8.88) is closer to S16 (12.52×7.41)
        So flange distance got to be around 17.526mm, not 44mm ?
        I gonna ask BM Factory directly and would let you know.

        ps I like your chart, but not segment with cine formats & gates sizes

        1. Thanks for the clarification, Ted. I was only aware of Arri PL mount used for both Super35 (APS-C) and fullframe 35mm sensors.

  30. TC Man with the movie camera

    Blackmagic Cinema Camera with M4/3 sensor Flange Distance: 19.25mm
    regardless mount (MFT- EF-, PL-)

    1. It seems no such adapters exist. I can see three issues there would be:
      1. The flange distance difference is 1.55mm, which means the adapter should be this thin. There are other adapters about that thickness, e.g. C/Y to EF. But the diameters of the mount may be a bigger problem: the throat of M4/3 is about 38mm, X-mount 40.7mm (according to some info I could find), so making an adapter to fit there could be a challenge.
      2. The adapter could not fit electronic contacts, so only fully manual lenses would work; you could not adjust the electronic aperture that is used in most lenses. (E.g. Laowa makes manual lenses though.)
      3. The micro 4/3 system sensor is smaller, and its lenses aren’t usually able to render to the corners of APS-C, so you should crop the images (or get black corners). Again, a few lenses are made for both m4/3 and Fuji-X, so for those this would not be a problem.
      All in all, theoretically might be possible with the limitations mentioned, but there’s seems not to be much demand for such an adapter.

      1. Fujifilm X-mount flange distance is 17.70 mm

        Micro 43 flange distance is 19.25 mm

        Yes that is a difference of 1.55mm – BUT in order to mount Micro 43 lenses on Fujifilm X-mount cameras it’s a NEGATIVE 1.55mm.

  31. I have a Nikon 1 mount lens (CX), the 1 Nikkor lens VR 70-300mm (Nano-coated), that has a FFD of 17mm. This lens is amazing but the Nikon 1 series cameras have been discontinued and have never been up to par with this lens (I used it on a Nikon 1 V3). It would be fantastic to be able to fit this 1″ mount lens on any other 1″ or micro four third sensors cameras, but the FDD is an issue.
    As far as I know, there are no adapters for Nikon 1 mount lenses.
    Do you have any suggestion or do you think I am toast?

    1. It’s unfortunate that Nikon changed mirrorless mounts so quickly. I doubt enough lenses exist for anyone to make an adapter.

  32. Hi Brian,

    I recently found out my family has these lenses that they used to use on their Canon T50:
    – Vivitar 70-210mm 1:4.5-5.6 MC MACROFOCUSING ZOOM (52mm diameter);
    – Vivitar 28-70mm 1:3.5-4.8 MC MACROFOCUSING ZOOM (52mm diameter);
    – Canon lens FD 50mm 1:1.8

    Do you know if any of them could be adapted to a Canon 600D? Thank you so much!

    1. That’s a no.
      Canon FD lenses designed for a body depth of 42.0 mm
      Canon 60D is an EF-mount camera with a body depth of 44.0 mm
      There are no FD > EF Adapters since they would need to be a NEGATIVE 2mm thick.
      You can adapt FD lenses to mirrorless cameras – just not to DSLR.

      1. Hi Brian, I know that Fd to Ef has negative 2mm, but some adapters offer an optical glass on it. Would be that helping with the negative or is it just the same? Thank you.

  33. Hi Brian,

    A theoretical question for now.
    Rodenstock 180mm large format lens to Fuji GFX body.
    What would be the length of bellows or custom adapter/tube needed for that to achieve infinity focus.

    Kind regards

    1. With most large format lens design, infinity focus is achieved when the distance between the film plane and lens board is equal to the focal length.

      180mm – 26.7mm = 153.3mm

      As with all adapters, if you’re even a fraction too long you won’t be able to achieve infinity focus so you always want to go a bit short so infinity focus is achieved with a slight extension.

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  35. Is there a difference between M39x1 and M39 or is that the same thing? I have a M39 rangefinder that I doubt has a 44mm flange distance. On a Canon EF camera it acts like a macro lens because of the flange distance. Am I missing something?

    1. Quoting the chart, “Leica M39 mount = 28.80mm”

      If you adapt it to a camera with a longer focal flange distance you’re essentially adding an extension tube and the lens will no longer focus to infinity – ergo as you say, macro.

      M39x1 was used on Soviet cameras & lenses. The threads are different.

      1. Just a note on this – Zenit M39x1 flange focal distance is actually 45.2mm, whereas M42 is 45.46mm. So while Zenit M39 lenses are often adapted to M42 with a mount step up ring, these lenses will not have infinity focus due to being 0.26mm to far from the sensor. RAF Camera is the only maker I know of who sells M39 adapters for the early Zenit soviet lenses.

  36. Any chance to adapt XL lens to NX? I am unable to find info about XL therad and flange focal distance. Is XL equivalent to EF (except the electric contacts)?

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  38. On a sony e mount with a flange focal distance of 18mm am I correct in thinking I would require a pin hole of 0.15mm?

  39. On a sony fe mount with a flange focal distance of 18mm am I correct in thinking I would require a pin hole of 0.15mm?

    1. I believe the way pinholes work is the distance from the sensor affects the relative focal length and the ratio of that distance to pinhole size is the aperture.

      In other words, two different sized pinholes placed the same distance from the sensor would both be the same focal length but the larger pinhole would equate to a larger aperture.

  40. Hi Brian,
    This is wonderful information.
    Thank you for taking the time to make this article.

    I have an old 16mm movie camera that I love and it has C-MOUNT. However, because of the design I am able to remove the C-mount receiver plate and I will design an adapter – which I will then get machined professionally. Essentially, I would be able to select any lenses I want – since I will make my own adapter.

    Which lens would you recommend? Can I put a 2022 manual lens made for a full-frame sensor still camera on my 16mm movie camera?

      1. Thank you for your comment.
        In your opinion, what are the sharpest lenses I can buy (new or otherwise) with a manual aperture ring?
        And what do you mean by overkill? Do you mean, if I put a 12mm lens, it will look like 24mm, because of the small frame?

        1. I think the crop is even more than that since movie film moves vertically – not horizontally. You’re only using the very center of a full frame lens coverage so it doesn’t make sense to pay for a lens that’s sharp ov er a much larger area than you need.

          The only way I see that making sense is if you need a super telephoto you can easily find a cheap manual 200mm F2.8 with an aperture ring that would give you about the same ‘reach’ as a 500mm F2.8 on a fullframe camera

          1. I agree. And I do not want to do telephoto. Quiet the opposite. I want to use wide angle lenses. What are my options of lenses if I don’t want any crop factor (or minimal) for this application?

  41. For wide angle you in practice need an original C-mount wide angle lens. 16mm cine image size is 10.26 mm × 7.49 mm, so the crop factor compared to full frame is about 3.5. A 20 mm FF lens will give you the same viewing angle as 70 mm in full frame. Laowa makes a manual 7.5 mm Micro Four Thirds lens, which would correspond a 24mm full frame lens, I guess that would be the closest you can get… if you don’t mind spending some money.

  42. Just to confirm…
    If I wanted to put a PENTAX K mount on my 16mm movie camera (with c-mount), I would have to machine a special mount, and that new mount would have a flange plane 27.934mm above the current C-MOUNT face, correct?
    Which is 45.46-17.526 = 27.934mm

    1. Aren’t you looking for a wide angle, Max? I don’t think you’ll find what you want once you factor in the crop factor down to 16mm movie format.

      1. Thanks for your reply Brian. Yes you are correct.
        For my wide-angle, I will go a different direction. I bought a 9.5-95mm angenieux lens with a C mount – and it comes with its own sidefinder. I will just use that as-is.
        My question above regarding pentax mount would be using a pentax k mount 20mm lens – which would give me a 70mm, after cropping. Actually, this would be more of a test. I just wanted to make sure my numbers are correct.

        1. Bear in mind that most adapters are made slightly short of the actual distance. This allows the lens to focus PAST infinity. This is actually better than being slightly too long as that would prevent to lens from focussing to infinity.

          I’m still not sure it’s optimal to crop a wide angle lens to use it as a telephoto when when theres gotta be a lot native 16mm lenses selling for dirt cheap prices these days. Normally people modify telephotos such as manual 300mm F2.8 lenses to use as a fast super telephoto.

  43. What are the specs for Aaton mount?
    I have a Zeiss 85mm f1.2 with an Aaton mount. Part of the CY mount that would have been underneath has been removed. Now I want to convert to EF but the mount I have bought sits too low. I’ve fashioned a spacer using a lens cap, about 1.5mm too thin so am going to try to find a shim for the base. And longer screws… I need longer screws.. But most importantly I probably need to know what the correct distance from rear lens element to sensor needs to be.

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  45. Pingback: Canon patents a bunch of cinema lenses including 40-100mm f/1.5, 18-45mm f/1.5 and 70-210mm f/2.5 - PHOTOGRAPHY! During Retirement

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    1. Nikon F mount has a 46.5mm focal flange distance
      Argus lenses with a 38mm thread have a 39mm focal flange distance
      Argus lenses with a 33mm thread have a 41.9mm focal flange distance
      I’m not sure which thread Argus C3 is but neither could be adapted to Nikon F cameras.

  47. Good day,

    I would like to buy a Venus Laowa 9mm FF lens (leica L) and then replace the bayonet with a Canon RF bayonet from a RF to EF adapter. The bayonet is about 3 mm bigger in diameter, but it has the same flance distance. I shall have to drill new holes, exactly according to the L mount bayonet lay-out. And of course the lens should be rightly aligned (to see the scales of aperture and focus distance on top. Do you foresee other problems?

    kind regards,
    Simon Bleeker, Netherlands

    1. I hear ya, Simon. It stinks that Canon hasn’t opened up RF mount to third-party lenses the way Sony, Fuji, Nikon and other mirrorless camera manufacturers have. You’re a braver man than me, I wouldn’t risk that.

      1. thanks for your reply, I am probably a bit slow, but I just found out yesterday that the Leica M version of the Laowa 9mm 5.6 will fit on a Canon R series camera via a Leica M to RF adapter, so I need to buy another version and an adapter and it saves me a lot of work and stress 😉

  48. Good Day

    I Was Wondering If it is possible to Mount a minolta mc or Sony a Mount into a Cannon Ef Mount? Thanks

  49. Hello Brian, could you give me your opinion about, to use an adaptor for FD canon lens to a Samsung NX mounting camera, i found mine FD 70-210 mm tokina telephoto, it can’t reach the infinity focus, and the canon FD 50mm is the opposite, it mean pass the infinity point. thank you

    1. Generally speaking, lenses focus past infinity when used with an adapter. If you’re using the same adapter with both lenses, both should either focus past infinity or if the adapter is too thick, neither should focus to infinity.

  50. Hi and thank you for all the knowledge you are sharing with the comunity. I am trying to wrap my head around adapting Mamiya RZ67 to L-mount full frame. Any advice will be apreciated. Thx, Gabriel

  51. Hello Brian, I have a Minolta Rokkor 75mm lens, very beautiful by the way, I want to mount it on a Fuji APS-C camera. Is an M42 helicoid 25-55mm adapter a solution? I also need an M42-Fuji adapter that will make a difference for the 57.30mm. For macro and “normal” photography.
    Thank you for sharing your knowledge.
    75mm – 17.70mm = 57.30mm Is this correct?

    1. Are you referring to the Minolta E Rokkor 1:4.5 M39 Screw Enlarging Lens?

      If so, you just need a M39 to Fuji X Adapter.

      Focal Length has nothing to do with focal flange distance. You simply need to correct for the difference in focal flange distance no matter the focal length of the lens. An EF lens > E Mount camera adapter is exactly the same depth for an 8mm EF lens uses the same adapter as an 800mm EF lens.

      1. Are you referring to the Minolta E Rokkor 1:4.5 M39 Screw Enlarging Lens?
        Right, it’s this lens

        But to be able to focus, the best solution would be a helicoid adapter?


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