Which Lenses work well with the FX9’s Autofocus?

Below is a list of lenses that have been tested with the FX9’s advanced autofocus system. Generally any Sony E-mount lens will work just fine. The Sony G series lenses are good and the G Master series tend to be even better. 
For third party lenses and adapters the situation is much less clear, so I have decided to list the lenses I have tested and invite others to contribute to this list via the comments area. The list is not exhaustive at this time but I will try to keep adding to it as I am able to try more lenses and and different adapter combinations.

Inclusion of a lens on this list is not a guarantee that it will or will not work, it is simply an indication of how it worked for me or anyone else that adds information about their own experiences. I welcome updates and any further information from any lens or adapter manufacturer.

If there is a lens you have tested on an FX9 please let me know via the comments how it worked so it can be added to the list.


Sony E (super 35mm) FE (full frame) lenses, G and G-Master including Zeiss ZA series. G and G Master  tend to have the best AF performance.

Tamron 28-75 f2.8 Di III RXD E-mount.


Sigma 20mm f1.4 ART with Sigma MC11 adapter. Works, but a little slow and occasionally hunts.


Sigma 20mm f1.4 ART native E-mount (very slow AF, hunting, contrast only?).

Sigma 85mm f1.4 ART native E-mount (very slow AF, a lot of hunting).

Sigma 20mm f1.4 ART Canon EF mount on metabones, comlite or viltrox adapters. Very slow AF, not really useable.


300x250_xdcam_150dpi Which Lenses work well with the FX9's Autofocus?

Tamron EF 16-300mm

Sigma EF 18-250mm


15 thoughts on “Which Lenses work well with the FX9’s Autofocus?”

  1. Thank you Alister for your efforts. I appreciate it very much! We have the Tamron 28-74 Lens with our A7III and with this camera (and also with the FS7) it works well. So we might keep it, when we‘ll change over to the FX9.

  2. Great info as always Alister, thank-you.

    What holds back other lenses from working well such as the Sigma Art E-Mount series? Do you think Sigma will be able to upgrade the firmware in the lenses?

    Also metabones EF adapters? We’ve all got cupboards of EF lenses, to have to go out and buy a set it Sony GM lenses adds a hell of a lot of cost to the FX9!

    Looking forward to be able to do dolly moves towards subjects etc at low f-stops which is not possible really without a focus puller…well not for me anyway!

    1. I think part of the issue may be that because this is a hybrid phase based system the camera needs to know the precise distance the lens is focussed to.

      With most conventional types of contrast based AF the camera tells the lens to move, the camera checks the focus, is it better or worse?. If worse go the other way, if better keep going. This continues until the camera is happy that the image is sharp. This is why contrast based is often slow and often hunts because it based on several changes of lens position until the best sharpness is achieved.

      But phase based is different. The camera is able to calculate the amount the focus distance needs to be changed to achieve the best focus and will tell the lens to move to focus position “x” in a single move. Then the focus is checked. If it isn’t right the FX9 appears to then revert to contrast based and tells the lens to move in or out a bit, checks the focus and so on this it will then start to hunt.

      So for the phase based element to work correctly the camera has to know by exactly how much to turn the lens or tells the lens to focus at a specific distance. With Sony lenses Sony will know exactly what amounts or what digital values that will be. With 3rd party lenses, especially going through adapters that have to translate the protocols that information will not be there, so the system falls back to contrast only and what you get is no better than the FS7.

      While I’m sure we would all like to be able to use all that old Canon EF glass etc. a lot of older EF lenses were never designed for phase based AF, so they will never work well with the FX9.

      1. Thanks Alister, very helpful info. So based on that the Sigma Art E Mount line won’t ever be up to snuff it seems for autofocus, it’s a pity.

        1. Even with the MC-11 the AF with the Art Lenses isn’t as good as Sony’s own lenses. It works, but is slow. I suspect this is a limitation of the Art lenses.

          1. It’s such a pity as the Art lenses are lovely and cheaper than the Sony’s. I have the 18-35 and 50-100 f1.8 lenses are they are very nice. Yes, the 50-100 breathes like crazy and they are S35, but lenses are a compromise after all.

  3. Hello Mr Chapman,
    my name is Gabriel Goubet, i am tv and documentary director in Strasbourg (France).
    I come to you modestly in this message to ask you simple question about Sony FX9. I watched entirely your Vocas’conference and others youtube stuffs and I can’t find any clear info about it.
    So, this my question : I would like to work with sony FX9 but it’s complicated to choose the right lens with it. Sony 28-135mm isn’t my first choice, I do prefer sony 18-110mm or fujinon 18-55mm BUT… are this two lens are ok with FX9 ? or are they work only on for APS-C cropped sensor like this website claim ?? (https://www.erwinvandijck.com/which-lens-to-choose-for-your-sony-video-camera/)
    I can’t find any info about that in sony’s website that’s why I come to you today…
    Thanks to you if you have time for my request,
    best regards
    Gabriel Goubet
    ps: i posted same message on your personnal blog before I came here, sorry for that !

    1. They are s35 lenses designed for s35, which is a very similar frame size to APS-C. So they will vignette on the FX9 when the FX9 is set to Full Frame. But they can be used on the FX9 in it’s s35 scan modes.

      1. waow ! thanks for speed response Mr Chapman !
        So… if I try to resume, to get all powerful specification in 4k of FX9 (zoom, autofocus, stabilisation) 28-135mm is the only target at this day…
        And if you want to use this wonderful Fujinon you can’t use it in 4k…
        Money investment in FX9 is complicated…
        thanks Mr Chapman !
        best reagrds

  4. Good morning (over here) Alister,
    I am about to invest in a long lens. Fujinon 46×13.5 or Canon 45X13.6. I am not going to even worry about the autofocus as i have manually focused lenses like these for years.
    However, Each of these lenses are properly used on a 2/3 inch chip, but none of the new cameras are going to be using chips of that size.
    Noting that this FX9 had a specifically designed smaller crop size as the s35 mode, will these large lenses cover ?

    1. A lens designed for 2/3″ works best with a 2/3″ camera. The new PXW-Z750 is an amazing 4K 2/3″ camera.

      You can use an optical adapter such as the IBE HDx35 to expand the 2/3″ image circle to s35mm. The adapter costs circa $4K but the image will be a touch soft compared to using the lens directly on a 2/3″ camera and the lens will be nearly 3 stops slower. Frankly you would be better off buying a 2/3″ camera.

      1. You are right about buying a 2/3″ camera the other solutions with adapters being soft is unacceptable.

        Z450 looks nice too. Doug Jensen shot a honey of a real with one. But the Z750 does have some major advantages – for sure. However, One major drawback is the lack of higher frame rates. HD is done. So advertising that it can shoot 120 in HD is almost silly. If the upc-onverters can keep things clean and sharp even that could have a usefulness.
        But- To have provided a path for the AXS-R7 would have been really quite brilliant. I really like that they are using the very solid SxS Pro X cards. Love that I can white balance precisely with the familiar toggle in the front. This is huge- because in 4k we know what is the key to the color science and unlocking perfect exposure. but holding the white balance in a memory cache is really useful for achieving other effects at times.
        Thank you for your response.

        I bought the AXS-R7 for high speed RAW at 120fps with my F55.

        I have been shooting SONY cameras rather exclusively for 26 years. I simply feel completely “at home” with them. I’ve used them in extreme conditions on shoots lasting for months at a time and they are rock solid.

        The Z750 looks very much like my DigiBetacam or my old and obsolete HDcam.

        1. Raw isn’t practical from 3 chip cameras as the signal is already 3 channels of R,G and B.

          There is still a huge amount of HD TV production, especially news and current affairs, so 120fps HD has a place. 4K 120fps is not an option with any of Sony’s current codecs except X-OCN and the SxS cards are not fast enough to record 4K XAVC even if it was possible.

          The Z750 is a very advanced camera. It has as much dynamic range as an F55, global shutter and full RGB colour, something the single sensor cameras can’t do. And it works brilliantly with big ratio zooms.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.