Video overview of MTF Services B4 2/3″ to super35mm adapter.

In this video I take a look at the MTF Services ( B4 2/3″ to super35 mm lens adapter. This adapter allows you to use a conventional 2/3″ ENG zoom lens on most video capable cameras that have a Super35 sized sensor or APS-C sized sensor. It comes in two parts, the optical converter (the expensive bit) and a simple low cost lens mount adapter ring. Adapters are available to work with the Sony PMW-F3, Sony E-Mount (FS100, FS700, EA50, NEX5 etc) as well as Canon EF (C100, C300, C500, 7D, 550D etc). To work correctly the lens must have a 2x extender. All is explained in the video.


25 thoughts on “Video overview of MTF Services B4 2/3″ to super35mm adapter.”

  1. Thanks for the review Alister. what are the concerns with the SD lens. the images there look good. I have a canon j11a sd lens and would love to make use of it. This adapter would appear to be the answer but the warnings about using sd lens is a concern

  2. It would be helpful to know how this performs on a chart.
    2/3″ lenses, HD or SD, are designed to work at their best with 3CCD prisms and are not designed to focus on a single plane so ideally there would be some correction in the adapter for this. The more expensive 2/3″ B4 to 35mm adaptors claim they do this extra correction. I expect for most productions the improvement is outweighed by the extra cost, but it’s an issue people ought to be aware of.

    1. There is no added correction in the adapter for the longer blue path in a prism but the lower resolution of the red and blue channels on a typical single sensor bayer camera means that a correction would make almost no difference to the final image. Because there is no prism with all it’s added aberrations and flare the end result on a single sensor camera are surprisingly good with typically less CA than you would normally see on a 3 chip camera.
      I agree it would be good to show some charts, but the charts will be different depending on the lens used and the quality of the end results is dependant more on the quality of the lens used than the adapter itself.

      1. Thanks for that Alister – I’ve always wanted to understand better what’s going on there. I must give it a go on my HJ18x28 which will become 70-1,250mm.

      2. Thanks for that Alister – I’ve always wanted to understand better what’s going on there. This might at last let me move over to a single sensor camera by using it on my HJ18x28, which will become 70-1,250mm and therefore quite useable for wildlife.

        1. The adapter is 1.5x, not 0.5x so 1.5 x 2 = 2.5.

          Your HJ18 would indeed become a 70-1,250.

          We used a Canon HJ40x14 which became a 35-1,400 for the shots of the lead singer Simon LeBon on the Duran Duran shoot. It was the only way we could get the range of focal lengths we needed. The camera was about 175ft from the stage shooting through smoke.

          1. “The adapter is 1.5x, not 0.5x so 1.5 x 2 = 2.5”

            But if the HJ40x14 lens is 14-560, with doubler engaged is 28-1,120, then with the MTF x1.5 it becomes 42-1,680.

  3. My last question, I promise.
    In the maths, is the x0.5 factor of the adapter applied after the x2 built-in doubler, or is it a x2.5 overall ?
    That would make a 500mm focal length become 1,500mm and not 1,250mm.

  4. I need to go back and check my notes on the adapter design. Our target design was for a total of 2.5 to 2.6x. I have a feeling that actually the optic is 1.3 x not 1.5, which makes the overall conversion approx 2.6x, it was a while since I developed it.

  5. Hi Alister

    I corresponded with you about this during the development. I think with an HD zoom lens your adapter solves a lot of financial and practical issues (ie investing money on high end Optimo zooms etc). Would an 2/3″ HD zoom on this adapter hold its own against say a Red 17-50 zoom in resolution? Was the lens in the Duran concert an HD?

    I have an EX1 which I’ve kept for shooting events and other shoots where it’s impractical to change lenses. With your adapter and a good quality hd lens, I could keep just the F3 and sell the EX1. And the depth of field is the same relative to the size of my other 35mm-sensor lenses, (Nikons, Tokinas)?

    With your rig, I wonder about the balance of the camera. Also, can the F3 mount handle the weight of the adapter and, say, a 2/3″ lens?


    1. The lens and adapter image quality is largely dependant on the quality of the lens. In general though, a high ratio zoom like a typical ENG zoom will not produce as good an image as a much lower ratio zoom. ENG 2/3″ zooms are designed as a compromise between large zoom range and image quality a compromise that’s normally quite acceptable ENG and documentary productions. All the extra glass needed to get such a large zoom ratio and the complex cams and optical trade offs degrade the image. A purpose designed low ratio zoom like the 17-50 is likely to outperform an ENG zoom, but it is only a 3x zoom, doesn’t have a servo etc.

      Like you I too had an EX1, but after creating the adapter I found I no longer really needed the EX1. It does make the F3 extremely versatile. If I need the ultimate in image quality then I use prime lenses, but when I need flexibility then a 2/3″ ENG zoom.

      The F3 mount is plenty substantial enough to support most compact ENG zooms. However the adapter kit includes an additional support bracket for 15mm rails. The lens used in the Duran Duran concert was I think a Canon HJ40x10, had to look at the photos to try and identify it.

  6. Hi Alister

    How are you power the zoom servo? having had a look on the net I haven’t really seen anything that seems to make that part of the process an easy fix. If its a DIY job where have you managed to get hold of the hirose connectors etc. for Canon / Fujion lenses in the UK?


  7. Can somebody help me with my math here? I have a Canon 9×18 lens with a 2x,? now with the 2x engaged is the 1.5x of the adapter included in the total multiplication, or after the 2x?


    None of my math adds up for me, cause I know that 9mm on a 2/3″ chip camera is not that wide in 35mm equivalence, and definitely not 27mm wide.

    1. The adapter is actually a 1.3x conversion, so the true figure is 2×1.3x which gives a conversion factor of 2.6x. However many 2x extenders are not exactly 2x so the exact multiplication factor will vary. Also this is a Super 35mm sensor not FF35. 25mm on a S35 sensor is not really all that wide.

      1. Ok, so let me redo my math.
        I’ll round up to 24 for nice even numbers.
        The crop factor for S35 is 1.5 or 1.6 depending on the camera.
        24×1.5=36 or 24×1.6=38.4
        Those numbers seem closer to what I was thinking.
        Thanks Alister.

  8. I’ve just bought an F3 body and want to use my Canon HJ22 with MTF B4 adapter. Do I need the Doubler in at all times?

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