The GH2 ETC with ENG B4, C-mount TV zoom lenses

softdrinks

Active member
I believe the ETC feature will enable GH2 filmmakers to fully utilized the ENG and C-mount TV zoom lenses and vault the level of GH2 DSLR filmmaking to a higher level. To my understanding, it's essentially a pure output of the crop of the center of the sensor without processing like line skipping and what not.
Here are some of my thoughts of using the ENG and C-mount zoom lenses.

The advantages:
1. maintaining the awesome aperture size of f/1.2 - f/2.0 of the TV lenses throughout the zoom! Usually with the ENG B4 lenses, the 2x teleconverter had to be enabled compromising light gathering (1-2 stops), but now, with the ETC feature, it is no longer needed thus being able to keep the aperture and focal range without having to double it.
2. Zoom. Bringing back the smooth zoom nature of the TV lenses back into DSLR filmmaking. Zoom was always an issue and hard to do with still camera lenses. But now with the TV lenses, zoom operation becomes more fluid and natural. This just enables the filmmaker with more options when deciding on a shoot. Zooms can be annoying but there are times when it is needed.
3. Image quality. I believe the TV zoom lenses have different characteristics from still camera lenses. Images might be a little more soft but the quality of the overall picture might be more closer to broadcast images. And since the center of the images is being recorded no need to worry much about corner sharpness.

Problems:
1. Mounting issues? I'm aware that there is a B4 to m4/3 adapter out there in eBay but for C-mount TV zoom lenses I am not sure if it can be mounted to the GH2.
2. The need of a good tripod and steady movement. ETC, because of it's 2.6x nature, movement has to be very stable or it will show quite readily on the shot. (more pronounced jello and jitters)
3. Noise? I'm not a technical guru but the crop of the senor might bring up more pronounced noise patterns??

In conclusion, I'm excited about the GH2. The adaptability of the m4/3 system to a wide range of different lenses is absolutely fun and it enables us to have more creative freedom and choices.
 
someone a long while back had already mounted one to a gh1 with very nice results. so rest assured it can be done =)
 
Thank you! I have gone through the post and have read about it.
I guess my main question would be: Does anyone know if there is a simple way to mount a Fujinon 12.5-75mm f/1.2 C-mount lens to the GH2 without having to do any separate machining? (provided that it will be only used for the ETC mode)
 
I just successfully connected my 3.5mm Canon TV c-mount lens to my GH2 in crop mode (about 88 degrees FOV with massive depth of field). The results look FANTASTIC, and hopefully I'll be able to post a video soon. I've been prowling Ebay like a madman for the past month because these wide cctv lenses are going to skyrocket in price once people realize their potential. Going to try out my Canon/Sony 12.5-75mm soon. Hopefully the results will look just as nice.
 
I kept one of my old Canon J15x9.5B4 KRS II Lenses from one of my old Sony Broadcast M7 Cameras. It does not have the 2x extender, but now there might be second life for it on a GH2. Powering up the zoom is another issue and another battery, but still do-able!
 
...
2. The need of a good tripod and steady movement. ETC, because of it's 2.6x nature, movement has to be very stable or it will show quite readily on the shot. (more pronounced jello and jitters)...
.

A B4 2/3" lens on a GH2 in ETC 1080 mode, become 20% less wide (and, of course, 20% more tele) than when mounted on a 2/3" chips camera.
The hand grip of these lenses make very easy shooting hand held, thanks to the GH2 light weight.
 
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