GT35pro Follow Focus
Order your GT35pro 35mm DOF Adapter here.

To order your GT35pro, please contact me and let me know which model you want or go to my new store at to order. I will try my best to answer all queries you may have. After you make payment I will need 3-5 days before I ship the adapter (maybe quicker). These units are made by hand and I test every adapter properly. PLEASE DO NOT USE MY HOTMAIL ACCOUNT FOR ENQUIRES AS I DO NOT CHECK THAT ACCOUNT. PLEASE USE or go to

Sunday, March 8, 2009

"5 micron or 9 micron or 20 micron ground glass?"

The 5 micron ground glass is the made using the 5 micron grade aluminum oxide powder. This means the powder is finer than the 9 and 20 aluminum powder. The finer the grind, the sharper the image will be but it will also cause blown out whites if you are not carefull eg. shooting sky. However, the finer the glass the less diffusion so therefore all 35mm adapters need to use a condenser lens to spread the light more evenly on the surface of the glass, just like in the gt35pro adapters. If you are building your own adapter and don't have a condenser lens then you will see hotspotting or vignetting in your images. The 20 micron ground glass will produce a much softer image but has stronger diffusion so some adapter makers use 20 micron or 25 or 35 micron ground glass without condensers.
This will cut down the vignetting by a measurable amount. But will give you a softer picture but less blown out whites. Also light loss is high and in situations when the aperture is stopped down to below f5.6, the grain becomes visible. The 9 micron ground glass is a good balance between the two other grinds. It gives a more film like softer image but not as soft as the 20 micron. I personally feel that the 5 micron is the best as it gives the sharpest and brightest pictures. We are now in the HD era and we want to keep that high resolution. Softer film look can be done in post production.

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GT35pro 35mm Adapter new feature

GT35pro 35mm Adapter new feature
version 4a

Superior condenser lens and 3 micron ground glass

Superior condenser lens and 3 micron ground glass
Canon FD 135mm f2.5 lens on gt35pro Nexus FD version

Superior Condenser lens with 3 micron groung glass

Superior Condenser lens with 3 micron groung glass
Zoomed in.

It's a cloudy day. Check out the very sharp and crisp image on the ground glass

With built in achromat. Notice the Lumix logo reflecting on the glass.

Comments from Users

"Dear greg_tay67,Just a quick note to say hi and thanks for the 35mm adaptor (Elite). It arrived last week with the rods coming this morning. I think UK customs had a bit of a bash around with it as the front lens looks like it had been pushed out. A quick wipe of the fingerprints and a dab of hot glue and all was fine.Must say, I am impressed by the adapter as a whole and it supplies images easily on a par with the redrock M2 unit I usually hire. I'll be recommending you to the other folks I know and work with around Scotland.
Thanks again"
Chris Gormlie.

"Hey Greg,Sorry I didnt send you an email letting you know, but yes, we have received them. I put the 5 micron glass in. I am very happy with the results. IN outdoor lighting with the supplied(Letus35) screen I could not close the 35mm lens down below f5 or 6. I did a test where I closed the lens down close to f20 with your screen and still had a somewhat usable image. This will be great for when we are shooting outdoors and need to buy ourselves some focal range. The image overall looks very clean also!!Thanks so much!!
James "

"Hi Greg,I got the adapter and it works great. I've got to get a smaller lens, as right now I've got a canon zoom and the whole thing is quite big. Or I've got to get some major support for the lens before I use it. I'm going to try and rig something with mirrors so I can see correctly. Love how it works! Thanks for your great work! I'll recommend you to anyone. Could you tell me what exactly the red button on the motor does? Thanks again,Susan"
Susan Emshwiller
Desert City Film Works
5025 Los Robles Street
Los Angeles, Ca. 90041

"Hello Greg! Thanks for your DOF adapter, it already got to our post office here in Prague. I have one week of shooting behind me. I am still learning, but the results are great!! On HF100 a have a visible hotspot, I can avoid it by using a bigger zoom. I playing around with settings, the best results I get with AV mode f2.0 (using CANON EF 50mm/1.8 II lens) + increasing EXPOSURE (+4). Cine mode does not look so great. I decided to buy small LCD TV green (7“) to see what I am shooting, because it is hard to have everything in focus and good composition with the picture upside down :). Maybe I can create my own Vimeo account, I will let you know. I am really happy with your GT35pro!"

"This is an amazing 35mm adapter for the price. The picture quality with the 5 micron is outstanding. I used the Nikkor 17-35mm/2.8 and got a beautiful image from corner to corner in such an affordable adapter. Hats off! Wow! I also tried the Nikkor 80-200mm/f2.8 lens and got brilliant image quality. I would say the Nikkor 80-200mm/f2.8 lens really compliments this 35mm adapter.The only problem being that the camera lens is supper long with the two attached."- John

"Hi Greg!
Already received the adapter this week. YOU DID A GREAT JOB. I'm very happy with it now, I have made several tests, and it seems to workprefectly now. Also the quality of materials and finish now, is superb. Many many Thanks
I have already sent you the shipping fees.
Many thanks for your support, you're really a great and talented guy. I will keep you tuned on how it's going with the adapter on my nextfilms.
Many Thanks",David

David XarachDirector de Cine / Filmmaker
Productor Ejecutivo / Executive ProducerMariachi Style

GT35pro Advanced HV20 and RED Camera Footage Intercut

The Bro Pact shot with GT35pro Elite and Sony FX1

Local Singaporean music video HV30 GT35pro Elite trial shoot in lowlight SD mode

Charlie's Nuts. 48 hour Guerilla Film Winner

Congratulations To Wes Roberts and Team Jumpcut for your winning Film

Wes Roberts, Director of Team Jumpcut email to me:

"As promised I wanted to follow-up and let you know how using the "Tay-dapter" worked on our 48 Hour Film. And my experience was --- fantastic! I think the finished HD product says most everything for itself; watch "Charlie's Nuts" ->
The adapter was consistent and provided no problems at all. It worked perfectly with my HV20, and I was able to shoot without any problems. I used everything from an 18mm wide angle to a 600mm ultra-telephoto without vignetting (unless I wanted it!). Most of the film was shot using my 1.4 50mm and my 1.8 85mm - but I rarely shot them all the way open. It says a lot for your device that I was able to see the weaknesses in my cheap wide angle, and conversely I could also see the quality of my fast nikkors! I have viewed the film on a huge 1080i TV, and even seen it projected in a movie theater and it held up to both environments.
I heartily recommend your adapter. I spent a lot of time looking at the footage demoed by other budget adapters and I thought I saw something in yours that seemed to fit the bright, pro-image I wanted to create, and I am happy to say that I was right.
Well done!

Please visit their website


1) The image will always be upside down unless you use an external monitor upside down. The larger monitor will also helo you to focus accurately. Some 35mm adapter feature a image flip prism add-on. These are very expensive (around USD$500) and takes away more light. Unless there is a hack for your camcorder you will need to re-program your brain or use an external monitor.

2) Always use a 50mm prime (fixed) lens as your main lens and other prime lenses eg. 28mm, 35mm, 80mm. Zooms will also work but they are much darker and will not allow you to shoot in much lower light. 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.

3) Use a tripod to shoot because you have to turn off the OIS. Shooting handheld with 35mm adapters can be done but the person needs to be very steady. I also recommend my GT-Viper rod support so you can balance it well on a tripod and not overtighten the vertical movement screws on your tripod damaging it.

4) Always make sure your ground glass is clean. Very light dust will disappear when the vibrating motor is on but larger dirt will show up as circle spots on your footage.

5) Make sure your motor is turning when shooting and always carry a spare battery. I never liked the idea or rechargeable battery on a 35mm adapter. You will be in trouble if your battery dies in the field.

6) For the best footage, make sure you have lots of light. Any DOF 35mm adapter eats alot of light.

7)Recommended shutter speed to shoot at is 1/50 for PAL or 1/60 for NTSC. Shooting at high shutter speed makes the grain of the ground glass appear in your footage. The gt35pro series of 35mm adapters allows you to shoot at shutter speeds up to 1/200 but this is not ideal as you loose lots of light. See point number 6.

GT35pro Elite Test Shots 5 micron ground glass

GT35pro 35mm DOF adapter test with 5 micron ground glass

GT35pro 35mm DOF Adapter 9 micron focusing screen indoor low light test

GT35pro Elite Edge Sharpness Test Chart 1

GT35pro Elite Edge Sharpness Test Chart 1
Shot with a Sony Z1 and cheap Canon 50mm mk2 at f1.8. Notice the soft edges produced by the 50mm canon lens when shot wide open at f1.8

GT35pro Elite Edge Sharpness Test Chart 2

GT35pro Elite Edge Sharpness Test Chart 2
Stopping down the Canon lens to f4.0 improves the corner sharpness dramatically

GT35pro Elite Edge Sharpness Test Chart 3

GT35pro Elite Edge Sharpness Test Chart 3
Stopping down to f5.6 improves the corner sharpness even more.

GT35pro Elite Edge Sharpness Test Chart 4

GT35pro Elite Edge Sharpness Test Chart 4
Stopping down to f8 shows that the Canon 50mm mk2 lens is sharpest at this setting. This also shows the excellent edge to edge sharpness of the GT35pro Elite. Some adapter makers use this term "Best edge to edge sharpness in the industry" but is meaningless without the test charts.

GT35pro Advanced test chart 1

GT35pro Advanced test chart 1
This test chart was shot with the gt35pro Advanced version with a Canon 50mm mk2 lens wide open. No processing was done except rescaling. Note no chromatic abberations and resonably good edge to edge sharpness. Soft edges are due to the Canon Lens. See my next chart

GT35pro Advanced Test chart 2

GT35pro Advanced Test chart 2
This is shot using my Digital Rebel Kit Zoom Lens 18-55mm f3.5-5.6. The lens setting is 50mm f4.5 See that the edges are really sharp as well as the centre. Comparable to the next 2 Letus and Brevis charts. This proves that the GT35pro Advanced has got professional quality edge to edge sharpness.

HVX200 Letus Extreme test chart

HVX200 Letus Extreme test chart
Letus Extreme using a Nikon 1.4 wide open. Looks like the soft edges are from the Nikon lens but I'm not sure

HVX200 Brevis test chart.

HVX200 Brevis test chart.
Shot with Brevis using a 50mm Nikon stopped down to f2.8. Better Corner sharpness when lens stopped down.