New lens Adapter Concept/Prototype


So here’s a little something I have been working on. This was born out of necessity and the reality of shooting 4K ENG style with a large sensor camera. Like many I needed a zoom lens with a good zoom range. 10x zoom was my minimum. While you can get some very nice PL zoom lenses, for example the Fujinon Cabrio 19-90mm this is only a 4.7x zoom. There are higher ratio zooms like the beautiful Angenieux 24 to 290, but this is a massive lens requiring a massive tripod and not at all suitable for ENG or handheld shooting. Sony F3 and F5/F55 users do have the option of the Sony SCL-Z18X140 which is an 18mm to 240mm servo zoom. It’s a good lens, not fast (f3.5 – f6.3) but useful, but quite a lot of money for such slow lens that is clearly based on DSLR optics. So, what about a DSLR lens? Well that’s what I started to look at, there’s plenty of choice, including the Tamron 18-270 a nice and useful 15x zoom range (just be aware that the Tamron’s focus back to front compared to most broadcast and film lenses). There are also the Canon and Sigma 18-250mm lenses.

Anyway… I’m trying to standardise on one DSLR mount and that’s Canon, so that means I need electronic aperture control for many of my lenses. Why Canon and not Nikon with it’s manual iris? Well almost all Nikon lenses focus back to front which is a real PITA. I purchased an MTF Effect Canon mount and control box, this gives me a Canon mount and now I have electronic iris control plus optical image stabilisation if the lens has it. But the electronics engineer in me started to wonder if it was also possible to add a servo to the lens to create a power zoom. After several abortive attempts, lots of swearing and not an insignificant spend on motors and gearboxes I finally got it working, a servo motor to drive an off-the-shelf DSLR zoom lens, or a PL mount zoom lens. Then I wondered about combining the zoom rocker with an iris control. This is where things got really interesting as I was delving into new territory for me and that’s micro controllers. In addition Canon don’t publish details of the language and signals needed to control their lenses. Almost no-one has completely cracked all the codes needed to drive the lens, so I had to reveres engineer the protocol. After a few weeks of tinkering late into the evenings (sorry to my wife and daughter!) I finally had the major codes and could program a controller to drive the lens.

Now it’s all combined into a single box. A zoom rocker and servo motor to drive the zoom ring. A thumb wheel on the hand grip that operates the iris and a second small box with a knob to control focus, plus image stabilisation control. This means you can fit handles to the ring and have the focus control wherever you want. I have also developed a miniaturised lens control box without the zoom servo and rocker. This is the size of a match box and includes a thumbwheel/knob for iris and a port where you can plug in the remote focus control.

The next phase is to add Bluetooth control. This should be relatively straight forward now I know the lens protocols. I can already add bluetooth to the micro controller, so I just need an App to talk to it. Anyone out there good at writing iPhone Apps? I’d really like to get full remote control of zoom, iris and focus on an iPhone.

When will this become a product? Well I am working with a well known manufacturer in the UK at the moment to see if we can make this an affordable product. If that deal doesn’t work out then I’ll go the Kick-Starter route and do it myself. It will probably end up as two different products. An all-in-one box with zoom rocker and Canon lens controls and a second unit that just has the zoom rocker and servo for use on PL or Nikon lenses.

19 thoughts on “New lens Adapter Concept/Prototype”

    1. It’s currently powered from D-Tap or the 4 pin hirose on the F5/F55. When using the hirose you can also put the camera into record from a button on the handgrip.

  1. Excellent work. With the electronic interface can you also mimic parfocal operation. From my understanding Sony does this with their pmw-350 kit lens. In fact I likely learned that fact from your website.

  2. Hello Alister
    I’m very impressed! As an electronics engineer and cameraman I can appreciate both the difficulties of doing this and its usefulness. Well done sir!
    I have for a long time thought that SLR lenses with auto focus motors would be excellent for remote focus control and with zoom and iris as well… Wow…
    A quick question though (two actually). I was recently hired to do some pickups for a low budget feature. One of them was a sky line establisher. I initially tried my new 24-105 Canon zoom and found it to be noticeably softer than both my Canon and Zeiss primes. No surprise there, but how do you feel SLR zooms are going to work on the new 4K cameras? Are we asking a bit much of them? Also, I have only ever needed to once perform an iris pull in narrative film making, so I don’t often make a fuss about de-clicking SLR lenses. I like having the clicks for precision. As a seasoned camera operator, how do you feel about this small compromise (even with 1/3 stop adjustments) when using your awesome new box? Thanks

    1. There is a lot of variation between lenses when it comes to sharpness, contrast and distortion. A zoom will always be a compromise compared to a prime lens. DSLR lenses are designed to work with 24MP sensors. A 4K camera only has around 9MP, so your working well within the design limits of the lens even at 4K. While a dedicated PL mount zoom like an Angenieux Optimo or Fujinon Cabrio will most likely out perform a similar DSLR zoom the difference at like for like apertures will not be huge when using smaller zoom ratios (say 4x). 10x and 14x zooms make more compromises in image quality, perhaps a bit of corner softness or more CA and these compromises will be better or worse at different focal lengths and apertures. At the end of the day zooms are compromises but for many shoots it may simply be that it is only by accepting some small compromises that you will get the shots. Take my storm chasing shoots. I could use primes and get better image quality, but when you only have 90 seconds to get a shot there simply isn’t time to swap lenses, so if you end up with a wide on the camera when a long lens is what is really needed, your just not going to get the shot. Using a zoom means I will get the shot. It might not be the very best quality possible but it will look good, is going to be better than I could get with an HD camera and a slightly compromised shot is better than no shot at all.
      It’s all about checks and balances. It is a compromise, but a necessary one. It’s not a huge compromise as I suspect the end viewer is not going to look at the shot and say “why is that so soft?” unless they have a side by side, like for like shot to compare. DSLR zooms are not that bad!

      All my prime lenses are de-clicked or never had clicks in the first place (like the Samyang Cine Primes). It’s not so much the issue of requiring a finer step than say 1/2 a stop, but more the ability to pull aperture during the shot. It’s not something I need to do often, but if I suddenly find I need to do it, I want a smooth aperture change. That being said, one of the issues with using Canon lenses with their electronic iris is that the operate in 1/8th stop steps and this is visible in any footage. Ultimately I am still committed to using Canon mount lenses simply because there are so many to choose from and they focus in the right direction. For primes I’m using the excellent and fully manual Samyang T1.5 Cine Primes.

  3. Hi Alister,

    I have been dying for there to be a servo zoom control for EF lenses . I tried adapters with 2/3 eng lenses but it just not practical.

    I work on a live network show where we do a lot of live on XD and shoot our pkgs on a C300.The live element always involves handheld and zooming.
    This would give me my dream option to do a way with the XD and just use the C300.
    Any idea when you think you have something ready for the field.

    I’d be more than happy to help test and show it off.

    Please respond if you’d like to talk further.

    Well done

    Trent

  4. Hi Alister,

    great prototype!! I wanted to order the Optitek Prolock+Optitron,
    but after seeing your concept I halted the order.

    Can you give use some ETA? Like Q4 2013 or after?
    By the way, thanks for your great job with this website!

    Best regards,
    Filippo

  5. Hi Alister,

    There is a whole market segment for which this product could have a big impact on, and that is live event market. I have been working at a church for 5 years now, running the video department. We don’t broadcast, but we do record all our services and project live up onto a large screen projection system.

    It seems that most of the products out there are for the broadcast world or the production world, and we are neither! Currently we use the old Canon XHA1 cameras, but there is little to no shallow depth of field, and when you have a crowded stage to shoot that would be a very helpful tool. But higher end broadcast cameras are so nose bleedingly expensive! And large sensor options don’t have the option for zoom control from the tripod arm that we really need for quick reframing on the fly.

    All this to say that this product would really open up a lot of possibilities for what is not an insignificant market segment. There are probably thousands of churches out there doing live video now, and of course there are live concerts of any type which would be in the same boat.

    Of course for our use, the ability to mount the actual control onto the tripod arm for a studio type setup would be ideal.

    I’ll be following the development closely so I hope it all goes ahead!

    Cheers,
    Sam Burton
    Chilliwack, BC, Canada

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