GH2 Help with external recorder and follow focus

ulisses

ulisses

Well-known member
Hello,

I need to buy an external recorder for the GH2, which one works better with the HDMI output. Ninja ? AJA ?

Also, I need a follow focus, but not sure if I can get it working with my Olympus 14-54mm, 20mm, etc...

Thanks for helping,
Ulisses
 
i could be foggy on this, but i seem to remember hearing debates about whether the HDMI signal coming out of the GH2 was effectively any better than the avchd compressed image that hit the card
 
Why do you need an external recorder. Are you in search of a better quality image?
I am also on the lookout for a follow focus.
 
wgzn said:
i could be foggy on this, but i seem to remember hearing debates about whether the HDMI signal coming out of the GH2 was effectively any better than the avchd compressed image that hit the card
Click to expand...

Well, with some of these crazy high bitrate hacks, the difference in detail may be mostly indiscernible.

However, using an external recorder will no only eliminate compression artifacts and record into a more editable format, it can also grab 4:2:2 color (some scripts are needed to extract it, however, since Panasonic appears to have tried to disable and scramble the extra color space).

For most of what I do, an external recorder is an added expense I don't need. But there sure seems to be plenty of good reason for someone to want one.
 
I have an opteka follow focus. it is a decent choice for the small amount of cash outlay. You can use it with your lenses you just need to get lens gears. Jag35 has them. You would need rails or some sort of setup to mount the FF.
 
ulisses - Martin Beek at http://www.marvelsfilm.com has successfully recorded to ProRes on the Atomos Ninja and posted his results here:

http://marvelsfilm.wordpress.com/2011/07/15/gh2-hdmi-output-recorded-with-atomos-ninja/

See the links in his post back to the key threads on dvxuser where Ralph B and other heroes here worked out the scripts needed to make it work.

As M. Gilden says, though, with the hack it doesn't seem that external recorders have much of an image quality advantage over high bitrate video straight out of the camera...

Cheers and good luck,

Bill
 
For visual effects that require pulling a chroma key, the extra color space could be pretty useful. Otherwise, I'm not sure I'd find it worth the effort to shoot with on a regular basis.

Aki- have you actually found avchd that difficult to grade? Have you tried converting to a higher color space before editing (5dtoRGB, neoscene, etc)?
Depending on your software, it may be giving you trouble with DSLR native formats.
 
Thanks for all the answers, I'm interested in external recording for direct PRORES recording and better color space (maybe?) for chroma-key. Audio inputs could be a plus.

Ulisses
 
the color resolution of the AVCHD files is not up to the task when grading begins.
Click to expand...

i find myself asking if we're being realistic in these discussions.

as much as i enjoy DSLRs, if your'e shooting your "feature" on an $800 camera im going to gamble that for the uses of about 95.7% of the people reading this; the gradability of what comes off the card and through the built in color corrector of their NLE of choice will be way more than adequate.

"yeah, the trees all leaned 17 degrees on that pan. but the color was excellent!"

facepalm.
 
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Allow me to visualize the problem:

blogGradingGreen2.png


blogGradingRed2.png


If I am going to have to pull hues from the red channel, serious loss of resolution will occur. The situation is not much better on the GH2, if at all.

It is already possible to use any cinematic lens desired, the resolution on the sensor is there, one could build a rig to shoot movies. The only obstacle that prevents near movie quality is the poor color resolution. If there was a way around that using an external recorder, even if it only helped only a bit, that is a valid reason to investigate for those in search of better picture.
 
ulisses said:
and better color space (maybe?) for chroma-key.
Click to expand...
You will not get better color sampling from an external recorder, because the GH2 doesn't actually output 4:2:2. In fact, you'll have more hassles because the GH2 outputs a "broken" chroma and you'll have to run a VirtualDub script on every file you record, in order to un-break the chroma and restore it to normal 4:2:0.
 
Has anybody tried to combine the color from external recorder and the internal codec? With any luck the other samples from slightly different position, so combining the two might provide added color information. This is pure speculation at this point.
 
That would be a nearly impossible nightmare. The color that gets output on the HDMI port doesn't match the color that the camera records internally. I'm not talking about color sampling, I'm talking about the color itself -- the HDMI output just isn't accurate. It doesn't accurately display the image the camera is creating.
 
the HDMI output just isn't accurate. It doesn't accurately display the image the camera is creating.
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and ladies and gents, THAT was the nature of my original response.

again, i will mention the potential folly of spending time and effort getting wound up in the esoterics of "grading" the output of an $800 cmos camera.

its nice. and for your uses (and mine) its more than adequate.
now go get one and get to shooting some video. quit worrying about things that arent going to matter at the end of the day. and when they DO - you can pay an expert to deal with it.
 
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Only the red channels and blue channels from different codecs would need to be blended together to see whether this would add color information. Like was mentioned, HDMI is inaccurate representation of the color but so is AVCHD. By combining two inaccurate red channels from different sources could give less inaccurate red channel representation. That's the theory anyway. In practice it might not work. But there is always the slight chance it could work and add some quality.
 
Only the red channels and blue channels from different codecs would need to be blended together...
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ok, go figure that process out in order to make your image a little "better"


i guess im just more of a storyteller than technician.
but DSLR people make me want to stomp on flowers : (
 
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wgzn said:
and ladies and gents, THAT was the nature of my original response.

and again, i will bring up the potential folly of spending time and effort getting wound up in the esoterics of "grading" the output of an $800 cmos camera.

its nice. and for your uses (and mine) its more than adequate.
now go get one and get to shooting some video. quit worrying about things that arent going to matter at the end of the day. and when they DO - you can pay an expert to deal with it.
Click to expand...

I have worked in TV and movie industry since 1990 as a camera man, editor and colorist. I have studied photo chemistry in university. It was always a dream to have a low cost cinema camera at the palm of one's hand and be able to fire up movie production at any time and any place. It is getting closer, but we're not there yet. Hence the curiosity.
 
i guess this gets into an almost political/religious discussion of whether that extra 12% matters to anyone other than the shooter or his peers?

personally, i put so much value on the story and composition, that i'm just out of gas when it gets to the esoterica of a little more ____x_____. and id bet my life that to the audience, if they werent shown side by side options - would give it a second thought. and my audience (whomever they may be) is really all that matters to me. they pay my bills and immortalize my efforts.

if i cant tell a decent story, im not going to lose additional sleep because some colorist guy complains about the latitude in my shadows ; )

but we all have our own mantle to carry
 
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The problem is that basically the quality is there, camera factories just do not allow using it. If more people demanded unlocking the full potential, we would get it eventually. Twenty thousand dollar cameras exist but they are seldom going to be on hand and ready when opportunity for some filmic recording present themselves. Magic hour does not last one hour and it does not necessarily occur every day. When it does, you will want to capture and immortalize it at the best possible quality.
 
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