In the Editblog garage: GT35pro adapter

By S Simmons. Filed in 35mm DOF adapter, filmmaking, HV20, HV20 gear, Internet resources  |  
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Here at the Editblog, we recently got our hands on a great little 35mm lens adapter called the GT35pro. This adapter is created by Greg Tay in Singapore. We thought this would be a great addition to the HV20 video camera kit so we are excited to shoot some footage and test it out.

The unit we are testing out is the GT35pro Advanced. Greg offers a number of different configurations that adapt a wide range of cameras and budgets. Unlike the “high end” 35mm adapters, Greg’s adapters are priced at a different place in the market. I think it might be hard to justify $1000 + for a 35mm adapter that isn’t used in a professional shooting environment to make money. And by that I mean it’s not always easy to convince your spouse or your bank account that you need a Red Rock M2 Indie Bundle for $995 when all you want to do is shoot your dog or your kid. Are there advantages to a more expensive adapter like a Red Rock or those from Letus? Sure there are but that’s part of working on a budget, compromises. That’s where an adapter like the GT35 line can hit a sweet spot.

This particular adapter is the GT30pro Advanced. From the GT35pro website:

This package consists of the GT35pro and power unit with a high quality 3 lens element achromat, coated on every glass for distortion free and chromatic abberation free and the sharpest video possible. This is NOT some surplus shed glass that others provide built in. Now upgradeable to Elite config. Only for camcorders with filter threading of up to 46mm. Price USD$340 + $15 shipping & handling* Tested compatible camcorders. Sony SR1, Sony HC7, Canon HV20, Canon HV30, Canon GL2, Canon HF100, JVC GZ-HD7.

Also included in our package is the $95 GT Viper Rod Support system. This acrylic rod system is a great addition to an adapter like the GT35 pro as handling the HV20 + Canon 50mm prime lens without it is possible but the whole rig feels much more secure with the rod support. According the the official GT35pro website, fixed prime lenses are best since “some zooms exhibit vignetting on 35mm adapters. The vignetting will be worse in low light and you might notice grain. Best lenses to use are f1.4, f1.8 and f2.8 lenses.”

I popped my 300mm zoom onto the GT35pro and while it is possible to shoot with the lens at full zoom it makes for quite a large and heavy rig. I will have to do some real test shooting with the big zoom lens to see how the images look.

This is a vibrating DOF adapter so in some of the pictures you will notice the light blue plug into the bottom of the adapter and single AA battery pack rubber banded to the rod. There’s a single toggle switch on the power unit to turn the vibration unit on and off. I’ve posted more photos on Flickr.

Greg is constantly making upgrades to the system. Since I received mine a couple of weeks ago he has added a tally light to the unit to indicate that the vibration is on:

This new feature uses a 9 volt battery instead of AA but you can still order a unit without the tally light. The vibrating is quite audible so it’s not hard to know that vibration turned on when near the camera but it’s nice to have the option of the light. He has also added a clamp to the rail system that clamps the whole lens barrel instead of just letting the barrel rest on the support:

That’s a great improvement.

So what’s missing from this article? Why footage of course. I’ve only had time to shoot just a few minutes of video on a cloudy, rainy day. Early tests look good but I am still learning how to use the adapter properly. It’ll be coming home for the Christmas break for some extensive shooting (and hopefully some sun) so expect footage after the first of the year. In the meantime check out the footage and testing that is available on Vimeo. We will have our own footage up in January. Stay tuned!

7 comments to “In the Editblog garage: GT35pro adapter”

  1. Comment by Quintessential Studios:

    That’s the most ridiculous thing I’ve ever seen! Not really but it is quite ridiculous looking! I think I love it. Questions I have are: 1) I see they have a version for the HVX200 but they say 72mm. Isn’t the HVX 82mm? 2) is the width and diameter of their rails the same as other DOF rails, so I could use their lens holder on other rails? 3) What kind of warranty do they provide? 4) with a vibrating object, I would expect it to break at some time. I wonder how long it will last.

  2. Comment by Scott Simmons:

    Good questions. I have put an email in to the creator of the GT35pro so hopefully he’ll chime in on some of these questions. Thanks for asking.

  3. Comment by Jeremy Schulz:

    I’m curious how audible the sound really is. Enough to pick up with the onboard mic? Serious work will of course require an external mic, but just wondering for the old run-and-gun. Thanks!

  4. Comment by Greg Tay:

    The sound is actually very soft. So far I haven’t noticed any motor noise in any of my test footage. Some also complained that they don’t know if the motor was on or not. That is the reason I added the power LED

  5. Comment by Greg Tay:

    Quintessential Studios,
    I am the manufacturer of the adapter and these are the answers to your questions.

    1) I see they have a version for the HVX200 but they say 72mm. Isn’t the HVX 82mm?
    a: The gt35pro Elite uses a 72mm achromat so you need to use a step down ring to step down from 82mm to 72mm. Even the big boys like Letus and Brevis uses a 72mm achromat and you need to step down the same way.

    2) is the width and diameter of their rails the same as other DOF rails, so I could use their lens holder on other rails?
    a: The diameter is 15mm, same as all other rods. The rods are positioned 60mm apart following the standard for rod support for matte boxes. So you can replace the acrylic rods and use other standard rods.

    3) What kind of warranty do they provide?
    a: I haven’t thought of a warranty scheme yet but I guess I can give a 6 month warranty. I only had problems before with a broken adapter ring and I shipped a replacement part. I have improved the construction and that part can no longer break. The adapter is made modular so it is very easy for me to ship replacement parts. I have had 2 adapters with condenser coming loose during shipping but it is easily fixed by just hot glueing the lens back to the mounting. I think these shipping guys must have thrown it down 2 storeys or something like that.

    4) with a vibrating object, I would expect it to break at some time. I wonder how long it will last.
    a: The vibrating part will never break because it is suspended by metal screws welded/soldered to spring steel/piano wire. These wires are used in the piano and very strong and flexible. I even have to use quite a bit of force to cut it with a pair of pliers. I can only forsee that the nuts coming loose from the screws. You just need to tighten it back.

    Let me know if you have any other questions.

  6. Comment by Susan Emshwiller:

    I have one of Greg’s adapters and it works really well. The image is flipped, so to shoot easily I concocted a DIY rig to hold my Canon upside-down. Didn’t want to spend money or have it be heavy— so bought a $5.00 plastic jug at Target. It is stiff enough to cut out lots of holes for access to controls, yet have it still hold up well. If you want to see ridiculous— look here:
    http://www.poptent.net/media/7628

  7. Comment by Greg Tay:

    Hi Susan, thanks for your comment. I really like the video you made on youtube.