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-   -   GH2 shoulder camera with 2/3rd inch lens (https://www.dvinfo.net/forum/panasonic-lumix-s-g-gf-gh-gx-series/506334-gh2-shoulder-camera-2-3rd-inch-lens.html)

Sander Vreuls March 23rd, 2012 02:24 PM

GH2 shoulder camera with 2/3rd inch lens
 
2 Attachment(s)
I just wanted to show my rig so far. My plan was to get a relatively cheap HD shouldercamera, with a manual lens.

Since I had some experience with using a digibeta viewfinder on my last build (with a Canon EOS 550D) I decided to combine that with a 2/3th inch lens.

The base of the entire rig was a cheap non functioning BVP-90 camera. I dissasembled and modified it completly. The height of the camera was lowered quite a bit, and there was an electronics box added at the rear. The CCD block was dissasembled and modified with a M4/3 adapter. This meant that any lens you mount on there actually has its full weight on the CCD block assembly which is attached to the camera body. The GH2 body only has to hang off the M4/3 adapter at the rear so it only carries its own weight.

I also used the lens plug from the BVP-90 and the viewfinder plug (which I moved and modified). The viewfinder is an SD Digibeta model, which receives an Y video signal from a HDMI > Y/C converter mounted at the side of the electronics box. Inside the electronics box there is a phantom power supply which feeds the front XLR input below the lens. It outputs the microphone signal into a beachtek adapter which was mounted in the box as well. The other (non-phantom powered) channel of the beachtek is at the rear of the camera, along with the controls the beachtek has (stereo, mono, aux etc). The adjustment for the channels will probably be mounted in the side of the box.
Both the lens and the phantom power supply receive 12v, the viewfinder receives 9.3v and the HDMI converter receives 5v. All these components (basicly everything aside from the GH2) receive power from the Anton Bauer mounted at the back.

Empty weight (no lens, no battery) is 3.0kg. With the Fujinon A15x8 and a Dionic 90 it gets up to 5.3kg, with the Hytron 100 it gets up to 7kg. It can be mounted onto VCT-14 plates easily as you can see.

I am sadly not done yet, the audio parts still have to fused together, and I need to apply some more weatherproofing and make everything look a bit better. Another part I am considering is adding a seperate audio recorder..

The lens is pretty soft in the corners when wide and fully opened up (like most B4 lenses on the 4/3th inch sensors), but when doing close up work its just fine.

As you can read a lot of parts are modified old camera parts or homemade, this made the rig pretty cheap to build.. Which was my goal :)

Thomas Smet March 23rd, 2012 03:16 PM

re: GH2 shoulder camera with 2/3rd inch lens
 
LOL. That is awesome. Having shot with cameras like that before it really meant something to me. Man I sometimes miss cameras like that. Sure they were huge but that had huge advantages as well. The size and weight really helped keep the cameras steady back then.

Killer job! Love the AB battery as well.

Bill Bruner March 24th, 2012 07:32 AM

re: GH2 shoulder camera with 2/3rd inch lens
 
Sander - a work of art! And a real inspiration. Congratulations on your progress so far. I'll bet you can sell these for more than it costs to make them...

Cheers,

Bill
Hybrid Camera Revolution

Sander Vreuls March 28th, 2012 08:09 AM

re: GH2 shoulder camera with 2/3rd inch lens
 
Thanks for the nice comments :) This rig is just for fun, not for any commercial projects. Been soldering quite a bit the last few days hopeing to get it done next week!

Also started modifying a old huge porta brace camera cover to fit.. So far it seems to be working :)

Chris Hurd March 28th, 2012 08:19 AM

Re: GH2 shoulder camera with 2/3rd inch lens
 
I don't know why, but I love projects like this one. Well done, and thanks for sharing!

Chris Duczynski March 28th, 2012 03:22 PM

Re: GH2 shoulder camera with 2/3rd inch lens
 
Nice work Sander.
Good luck with the porta-brace - I'm still working out how it fits so I can work easily.

Sander Vreuls April 28th, 2012 03:38 PM

Re: GH2 shoulder camera with 2/3rd inch lens
 
Since the last post I modified the porta-brace (not 100% happy yet.. my sewing skills are pretty horrible) and I added a Zoom H4 on a bracket. Still figuring out how to properly integrate it in the system.. It will get power from the camera rig, and I will probably go line out to the GH2.

I also just bought a bigger viewfinder (BVF-20WCE, 2" 16:9 instead of 1.3" 16:9) and a Fujinon A8.5x5.5 wideangle with extender.. For the current Fujinon A15x8 I got a ND4 filter to help out in the sun a bit..

Sadly I think I have a problem with my B4 to M4/3 adapter since the sharpness is not optimal.. might have to buy an expensive off the shelf model :)

Rohan Dadswell April 28th, 2012 05:19 PM

Re: GH2 shoulder camera with 2/3rd inch lens
 
The Fujinon 5.5 wide angle is not a very sharp lens, so it may not be your adapter - I've given up using mine on the AF & GH cameras.
Also even with the 2X extender engaged there is some vignetting - this lens was designed way back when all broadcast cameras were 4x3 standard def. I've tried the newer Fuji 4.5 and it is much sharper.

Sander Vreuls April 30th, 2012 10:54 AM

Re: GH2 shoulder camera with 2/3rd inch lens
 
Hmm real shame.. still got it on the way so haven't been able to test yet. Hope I can test out some lenses at work to see if it really is my adapter.. Sadly their lenses are a bit out of my price range :)

Sander Vreuls May 6th, 2012 01:19 PM

Re: GH2 shoulder camera with 2/3rd inch lens
 
Just got the wideangle lens.. I indeed have some vignetting, especially with the hood on. I can shoot without the hood and maybe crop it into a wider aspect ratio.. I will try the lens out in the street and see what it does..


I also got a bigger (BVF-20WCE) viewfinder for the camera and it's so much better to focus with than the smaller BVF-10 I had.. Focusing becomes so easy.

Chris Austin May 6th, 2012 02:47 PM

Re: GH2 shoulder camera with 2/3rd inch lens
 
I think this is a really great project. The addition of all sorts of sprouting arms and counterweights so an SLR seems like such a step backwards. The shouldermount ENG format has evolved over years and stayed around because it works. Just like the compact handheld.

So why not make a box/cage/assembly that you can put an SLR into and turn it back into something familiar? I thought the new Zaccuto Tornado at NAB was a step in the right direction as it works with the camera rather than fighting it, but this is even better. A really fun project!

Gaetano Capolino May 7th, 2012 02:39 AM

Re: GH2 shoulder camera with 2/3rd inch lens
 
The reason why B4 lenses appear quite soft in the corners is because those lenses are made to focus the light rays passing through the beam split filter on fron of the 3 CCD's block. On the oter hand, GH2 and all the other DSLR's use a single focal plane sensor. Using the ETC mode a B4 lens becomes parctically unusable wide open, you need to close down a couple of stops to get acceptable results.
Engaging the 2X externder you get the same effect because the 2 stops loosing, however the extender adds some softness and makes CA look worst.

Mounting a B4 lens on the GH cameras is a comprimese and has its downsides, nevertheless they are more handy to use than a standard photo lens.

The A8.5X5.5 has a 1.7X extender instead of the classical 2X, this is the reason why it vignettes visibly when mounted on a 4/3 camera.

Sander Vreuls May 7th, 2012 02:33 PM

Re: GH2 shoulder camera with 2/3rd inch lens
 
Eeek. Having a 1.7 times extender does explain a lot.. real shame :/..

Might go ahead and sell the lens to try and see if I can find a wideangle with x2 extender instead.. The lens is sharp enough to be honest, if it wasn't for the vignetting it would be a keeper..

Added the viewfinder and Zoom H4:
http://i14.photobucket.com/albums/a3...0/GH2Fuji8.jpg

Sander Vreuls May 25th, 2012 06:08 PM

Re: GH2 shoulder camera with 2/3rd inch lens
 
Did a quick video with the rig (no sound), to test various things, amongst which detail in unhacked camera and how the rig handled... (which is why it includes a short walking bit where I hold the camera at waist height)
Some notes:
- Fujinon A8.5x5.5 with 1.7 extender
- 1.7 extender is not enough, so it vignettes a lot plus the hood is visible in the wide angle shot
- Blue lens flare, it was quite annoying to see on all footage..
- Need a ND filter, this was shot at F/8-F/11 ish.. (Iso 160, Extender on the camera, and shutterspeed of 50)
- Shot at 1080p24, unhacked camera.

So now I am trying to look for another wideangle lens with a x2 extender. Sadly they seem to be pretty expensive.. I have 3 lenses here now so I might sell 1-2 to try and get funds for another wideangle.. I'm going to try out the lenses in a few days to see how they hold up. They are:
- Canon J14ax8.5 with x2 extender
- Fujinon A15x8 with x2 extender
- Fujinon A8.5x5.5 with x1.7 extender

Sander Vreuls June 16th, 2012 08:58 AM

Re: GH2 shoulder camera with 2/3rd inch lens
 
Just won an auction for a seperate B4 x2 extender. This means I can go to cheaper lenses without x2 hopefully. Also finished up the audio. It looks silly but I have 2 shotgun mics mounted now, seeing as the Zoom H4 that I have supports either 2 internal mics or 2 external.. so I went ahead and used 2 external mics.

I was also desperatly in need of a ND filter.. however 95mm (size of Fujinon A8.5x5.5 filter) is pretty expensive. So I bought a 37mm ND filter from ebay and modified that to fit inside the B4 to M4/3 housing, so it is a bit permanent at the moment. Backfocus is still fine and doable. The filter is a ND4 so not that bad, just keeps it a bit down in the sun..

On my next model (after the summer) I want to try and see if I can build a filter wheel assembly for the camera :)


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