Making GH2 the ENG camera

panini

This is my GH2 Projekt: I want to adapt a fujinon 2/3 to my gh2 via a B4 2/3" CANON FUJINON ENG lens to GH2 G2 AF100 AF101 E-P3micro 4/3 adapter and power it with my v-mount Akkus. As long the lense has a range extender you don´t have to use the ex-mode, what can´t be monitored on the hdmi out :-(

I want to power also the zoom to get this ENG-stile of shooting. If possible I want to start and stop recording via the trigger at the zoom handle, but I might skip that, because I might loose the ability to use the mic-port for an external mic. I doubt that both is possible at once... Anyone experiences using a Y-splitter?

As a premixer I thinking of a Rolls MX 54s Audio, or a juicedLink CX231 Audio Mixer. I planing to use a Varavon Screen Loupe EX GH1/GH2... The only thing I can tell at the moment - the hack worked great. I´m using a SanDisk extreme pro 64 GB and started with the "no adverse settings". But with 42 mb/s no constant recording ( at least one hour in AVC 1080/50i) was possible. So I altered the settings. I will use for narrative film making a FSH preset with 42 mb/s and for events a FH preset with 32 mb/s. This works so far... Quality wise I tested my gh2 vs. my old JVC GY HD 200B (1440x1080 50i). I recorded the same motive at the same time and I have to admit the JVC can´t compete against the gh2´s resolution… and that´s the reason I´m doing all that here.

mordiu

My humble apologies, I am planning to setup an old Angenieux servo B4 lens on Gh2, and quite happy I find this old thread.

Do you happen to have the schematic for GH2 lens Jack ? Tho there are people selling on Ebay nowadays its still...$100 dollars quite pricey for a college student. I am not a technical person but this will be a good experience.

Now... to save up for that lens adapter!

Thank you!

Roberto

@Galvoguru

Yes, you just might be right - a modded GH2 just could become a sought-after item, like a Bolex Super-16 conversion. Or, on the other hand, like the original Sony Walkman, the original item itself may gain cult value, as untouched as possible. I learned the hard way - I drilled a hole in my Walkman for an external mic; worked perfectly but destroyed the value. :-(

All these decisions can really only be dealt with using risk analysis, even if to some, a $700 camera seems small. Companies practise risk analysis for everything. Once you learn the basics you'll be ready to understand how the GH2 got built and sold the way it is.

I'm attaching a simple Risk Analysis Calculator spreadsheet, written by a Dr Gary Hinson. I've filled-in some example parameters I can think of, but haven't allocated given numeric values to any of the fields. That's up to you. Look for tool-tip explanations. The numbers in red boxes are the calculations which the spreadsheet does for you, according to weightings Dr Hinson has worked out.

[Sorry about the Implement Selective Training title of the spreadsheet; I forgot to change that from my last analysis].

Whether or not you find the calculation meaningful, the simple act of writing it all down adds up to dealing with it.

Risk Management procedures to be employed, reducing or eliminating each threat
Benefits to be added up (another calculation - just make it up yourself)

I must add, I have one benefit of my own which I must balance against the risks: Without modding things to do what I want, I suffer frustration which doesn't go away. So sometimes I open something up immediately on purchase, voiding the warranty just to get that out of the way! Modding gives me the satisfaction of taking control of what I've paid for.

Galvoguru

@Roberto. Yes I did read the input from @svart, and it's another possibility. I did wonder if a modified GH2 would actually be worth more than a 'standard' one, I guess I'm thinking of re-sale value, people may be prepared to pay more for a modified GH2 that had a dedicated remote socket and headphone socket as well as the existing mic/remote socket, there could be a business opportunity here LOL...

FW200

@Galvoguru

The adapter was actually homemade, from the existing CCD block combined with a M4/3 minolta adapter I fit on there. Not ideal but I didn't have the budget when I started the project to get a 300$ B4 to M4/3 adapter. Eventually I do want to modify the rig to have one of those adapters, and make it so I can put on other adapters as well..

Roberto

@Galvoguru

If you're reluctant to drill into the case, it gets hard. A 2-position solenoid would enable soft press for focus. Maybe we could consider using a similar extension ribbon for the shutter button as I suggest for the LVF - either re-locate the whole button to the handle outside or else a 2-position SPDT momentary switch. (Once again, you can see how parts salvaged from a bricked GH2 would be great). Of course, A Hirose->Lens control unit patch is highly usable.

BTW, see what you can make of @svart 's incursions into the idea of, say, a break-out box connected to the mic input PCB as an alternative to the external input socket, thereby freeing it up for use as a remote shutter.

I must admit my own dedication to 3/4 ENG lenses has its limits. I would like to create a DSLR->ENG adapter rig which will out-live the present GH2 and onto GH3 and beyond. I want to make use of the new while not throwing away what works in ENG.

Galvoguru

@mikel. The results you're getting seem to be typical of what others (including myself) have seen. I have a couple of J lenses, the image quality isn't bad but I've not really had time to see how the images look when using the camera on a 'real' job (need to get the audio side of things sorted first). The softer image from an SD lens may look quite nice, the softness is 'organic' and in some situations may help to give a smoother look to the picture. When you viewed your footage on a 'big screen' and at full resolution what where your first impressions? @Roberto. Using the external mic socket for record trigger is not an option I'm going to go with. For me (IMHO) the external socket is of more use for using external mics (although it wouldn't be difficult to have 2 different lead configurations so you could swap between ext trigger use or ext mic use). Thanks for the info re the trigger voltages, this confirms the tests I did in our earlier communications. Re the audio control box, I was going to include switchable 48 Volts for both channels as well as a mic/line switch and gain controls. There would be a headphone amp and monitoring could be switched between CH1(L)/CH2(R) or 'mix' (1+2). The one thing that's not here is monitoring the playback audio (witout using an external monitor), the only way to solve this is to take a tap off the internal speaker (as I've already mentioned) but of course this means opening-up the GH2 and having a flying lead for the signal (not very nice...), I don't like the idea of drilling a hole in the body for a socket. Either way I need to make a decision here. I do want a remote trigger for the record function and I'm looking at the possibility of using a small solenoid to operate the record button. If you have any suggestions please let me know...

Roberto

@Galvoguru - Yes, please! When somebody finally achieves a hardware hack it will certainly deserve its own thread! May the force be with you.

@Mikel Very good use of ENG technique. I would like to see your setup.

Those of us who've learned that kind of coordination know it can only be achieved with an intimate body-machine practice where all the controls are at our fingertips.

Compared to that, most rigs are like taking a shower in a raincoat.

For me, the idea of using both hands just to hang onto my camera is ruled out. The handles of my so-called shoulder rig are still in the box they came in. That kind of setup is fine for composed shots, but not for this little black duck. I'd even like to be able to pick up any DSLR rig and have my fingers fall naturally upon the buttons.

Like others, I'd love to use my SP parts [the mics are good]. I even like the Steam Punk,street-cred look of the full camera with GH2 at its heart. Its weight will also stabilize it for shooting. But I have no 1995 nostalgia for that 10 KG on my 2012 shoulder.

Even if we do nothing else, a finger (or thumb) record button isn't rocket science.

(from http://www.robotroom.com/Macro-Photography-2.html)

also see External Shutter Trigger Circuit for GH2? thread at http://www.personal-view.com/talks/discussion/1141

mikel

Results of my setup. Used a basic Ebay shoulder mount. Small12v brick battery w/d-tap to power the lens. Strapped the batter to the back of the shoulder mount for ballast. All hand held. Rode Video Mic just plugged directly into the GH2. Fujinon 15x lens. Note: that you will get some soft corners and CA wide open. Things clean up nicely at f4, great at 5.6. The better lenses are the Canon "J", not "YJ". As well as the Fuji Pegasus III are pretty good. My lens is an average quality Fujinon. Your mileage will vary. Backfocus is critical to get a sharp image. Though I have not tried it yet, someone stated that a crossover lens would solve the soft corners issue. But they are more expensive.

With some of the new power zoom "PZ" Panasonic lenses, the ENG features are becoming more incorporated IMO. Then you could still have use of the electronics and OIS. Just waiting for a higher max f-stop version of the PZ lenses and then you could ditch the whole 2/3 ENG experiment IMO.

Galvoguru

@Roberto. Yes, it would be nice to have a 'donar' GH2 so we could all have a real good look at it. Bottom line though is that I cannot use the camera in the field as it is so whether I like it or not I'm going to have to come-up with a design. When I make any progress or have some useable info I'll start a new topic. Don't know what you think? But I have tested the GH2 with an external mic (cam audio set on minimum sensitivity) and I thought the quality was fine, not too much system noise and the frequency response sounded good. The mics amps used on the input to the GH2 aren't the best BUT they are 'low noise' types...

Roberto

@Galvoguru

I am looking forward to your design. Yes, modding a new camera is a difficult personal choice! Unfortunately we haven't yet sourced any bricked GH2s to play with. As much as I want to, I haven't opened my own.

choplair

@FW200 I really like your ENG rig !

Re-using DigiBeta parts make the whole thing looks nice and certainly feels nice too (confortable shoulder pad & good view finder positionning).

Actually I am planning to do something very similar to you since I have some BetaSP cameras around me to recycle.

One question : for mounting the B4 lens (that I will use too), you are using the standard mount located on the DigiBeta head, OK, but then how do make it fit the GH2 sensor exacly ? Are you using some kind of lens adapter that is invisible on the picture, or did you made some precise locking system for the GH2 so that it is extacly in the good position to received focused image from the B4 lens ? I am curious about this point !

Roberto

IMHO, the mainstay of ENG camera skill is the fast use of a true shoulder-mount. The solution for the DSLR's inability to be placed to the rear of the eye is a minimally - invasive mod. See http://www.personal-view.com/talks/discussion/2555/gh2-hardware-modifications-not-for-the-faint-hearted/p1

Galvoguru

@Roberto. Yeah I already had a look at that thread. That's why I thought I would do a little investigation work! I'm not sure about 'hacking' away at the camera, I only bought it a few weeks ago BUT it really needs an external box of tricks to make it easier to use in the field. I'm probably going to make an external 'control unit' with 48 Volt phantom power, mic amps and a headphone/monitoring amp. I've got a couple of 2/3" lenses and the 'Polish adaptor'. Today I got a chassis mount Hirose lens connector, I want to be able to plug my lens into my 'boxof tricks' and have electric zoom + record start/stop function, this is why I need to have the remote record function sorted. There's quite alot of planning to be done + design and test the circuit, I also don't really want to void my guarantee, which means I need to be careful how I go about modding the GH2...

Roberto

@Galvoguru

Good work. I'd like to see a circuit diagram here.

Have you looked at the schematics at http://www.personal-view.com/talks/discussion/2555/gh2-hardware-modifications-not-for-the-faint-hearted#Item_22 ?

For some, audio mods are some sort of holy grail. There are simpler things we could tackle.

Galvoguru

@panini. I did some testing yesterday and unfortunately is is not possible to use the external mic socket and remote at the same time, bummer! FYI. Tip+ ring 1 is mic inputs + sleeve is ground connection. Ring 2 is the remote terminal, connecting this to ground enables the external inputs (this is why you can use a regular 3 pin 2.5mm plug to enable external mics). I did some experiments to see at what voltage the shutter operates, I used the phantom power which is present on the mic input lines to activate the shutter (ring 2 + sleeve), the phantom power voltage is 2.5-2.8 Volts, when the voltage on ring 2 drops to about 0.8 Volts the shutter activates and the camera goes into record mode, BUT once the camera is in 'record mode' you cannot enter 'external mic mode' without first stopping recording (by raising the voltage on ring 2). if you reduce the voltage on ring 2 down to ground the camera switches to external mic input BUT doesn't go into record mode. Yet again it seems Panasonic have gone out of their way to make life difficult... I may open-up the camera and have a look at the connections on the record button to see if an external trigger is relatively easy to sort, I also want to take a tap off the internal speaker to power a proper headphone amp.

omellan

@Galvoguru & panini. I don't need any remote because I hold the GH2 body with right hand when shoulder filming. This lens is a Nikkor 17-55 DX 2.8, it has the perfect range for interviews and I use a Novoflex adapter to control aperture. The SoundDevice MixPre has better preamps than most camcorders so recorded quality is very good.

panini

@ Galvoguru. I am very interested if this would work. Do you know the pin assignment of this 4 Pin 2.5mm connector. tip, ring1, ring2, sleeve=? @ omellan. I like your rig. I worked several times with this sound divices mixer, how is the recorded quality? What lens is this?

Galvoguru

That's an interesting rig! Do you have remote record start/stop? What lens are you using?

omellan

Hi, this is my ENGH2...

Galvoguru

It does say in the manual that you can start/stop recording using the remote shutter if you are in 'creative motion picture mode'. I also noticed looking at the picture of the panasonic remote that it uses a 4 Pin 2.5mm connector, the circuit diagram for the external mic/remote socket shows the fourth pin being used for something other than the left or right mic input, I think it may be possible to use this 4th pin for start/stop whilst still using external mic/s. I'm going to get a 4 pin mini jack and do some tests to see if I can trigger record...

FW200

Because I used old parts it's actually a pretty simple and cheap system.. Using a screen loupe does make it trickier in terms of length and counterweight..

I just start the camera with the recording button the camera itself, I haven't tried starting it remotely. However when searching I found some references that it wasn't possible.

panini

@ FW200. Where do you trigger the recording. Are you using the trigger button of your fujinon? If using a remote trigger, can you also use the mic in 4 audio?

panini

@ FW200. Thank your great picture of your system. I´m flabbergasted ;-) My plan is not that close to a real retro machine. It looks real y well made and I doubt I could realize it in this perfection! I will use a Varavon Screen Loupe EX as a viewfinder, which unfortunately will extend the rig a bit, but it won´t be that massive...

panini

@ Galovoguru. thank you 4 you valuable info! I have also tracked this adapter on ebay. Thanks for confirming that this is a quality adapter - I´ll gona have one, too. I had the 25p/24p strobing experiance with my first JVC (GY HD100) I was not used filming with this kind of raw `time resolution´. I was used to 50i. With my next JVC i was able to use a 50p mode- which I still love... But you seem to have a different problem, because you are telling you don´t face this problem using your DSR-450 in 25p mode - strange... Regarding shutter speed: I use it sometimes also to aviod a aperture smaller 11 or 16, having set the ND-Filter already... With GH2 there is no ND and if you don´t have the opportunity to use filters, you only can dial down your ISO. What´s left then is shutter speed... Here again. When filming in 1080/50i using an exposure time of 50 it strobes at least in the viewfinder (I will test that with a recorded file) It is smooth when using 60 in my fiewfinder - that´s strage, too... so when there is motion I use 60... I´m filming in manual movie mode, AVC HD 1080i, rec quality FSH (42mb/s), exposure mode - M, bodyfirmware 1.1 and the actuell hack. My ISO does not change...

Meierhans

Depends on peaking i guess. ;)

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