GH2 How are you dealing with color shift?

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DevonH

Well-known member
We have had several threads now that cover the fact that the GH2 shifts color when it's recording, with some general notes on how to deal with the issue. To me, it's frustrating that even with my $1100 DP6 monitor, that I can't trust what I'm seeing. I fully understand that the GH2 was not built to function mainly as a video camera, yet it seems a pretty glaring shortcoming. On the other hand, I've seen incredible work with the GH2, so I know that it's not a issue that is incapable of being handled, and maybe that's why I have been unable to uncover a lot of work that's done for clients, and not personally for the shooter's project. (Another subjective comment, as I haven't searched every nook and cranny of the net, or even most of them) I know we've beat this issue to death, but I'm hoping that we can get some really in-depth analysis and perhaps someone has discovered the solution.

I see the following...

-The DP6 screen is slightly warmer than the GH2 LCD, definitely a predominant orange tint.
-After pressing record, both the GH2 and DP6 go cooler.

I need to look into this in a "set" setting, this was shooting in the living room under tungstens, full manual.

I suppose the short answer here is to record a test clip on location as a reference point, and tweak from there.

What are your observations on the shift, and how are you overcoming them? Have you adjusted the color settings on the GH2's LCD, adjusted the color settings on your DP6/Marshall/Etc.?

-Devon
 
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I tested with my 2x55 5600k flo fixture, with no other light source, camera set to 5600k WB, and the shift was absolutely minimal, the histogram did shift slightly towards the center.
 
What color settings are you trying to adjust in cam? Seems like you have to know which color profile you want going in. Then just adjust white balance and exposure and you're good to go. What the screen shows is almost irrelevant, especially if you're shooting a flatter profile.

Cheers,
Pete
 
Right now I'm shooting Smooth -2 -2 -1 -2, which is a fairly flat profile. But how can you know if you're properly exposed if the LCD isn't accurate?
 
I've done the method of light, then hit record a few seconds to look at it, or take the SD card to a computer and check it out there.

Truth be told, at this point I've shot with it so much just messing around that I know what I'm getting when I look at the screen and how it's gonna look when I get to the computer, then 5DtoRGB it. Don't let it scare you, it's just a matter of getting used to it.

Also, I tend to use the EVF a lot more than I thought I would. It helps a bunch.

I haven't managed to figure out the green cast just yet, but I suspect it's just a balance on the adjustment grid. Typically isn't hard to pull the green out if everything if the subject is exposed well enough, but under exposed is gonna be a tough one.

Also, trying to re-white balance an overly warm scene is a nightmare. Avoid it like the plague or make it part of the scene, because it's going to be VERY hard to get it out without wrecking the image.
 
Use manual white balance, adjust your color temps according to your light source. Go back into the white balance menu and adjust the white balance hue: 5 down towards magenta and 5 right towards Blue.

Keep in mind, whenever you adjust white balance for color temp the white balance hue resets so it'll have to be readjusted to neutralize the yellowish/greenish tint.
 
My DP6 still had a considerable shift after pressing record in my flo test.

Kholi, are you overexposing via your eye, or using the exposure bar/histogram? If the latter, have you found a sweet spot?
 
DevonH said:
My DP6 still had a considerable shift after pressing record in my flo test.

Kholi, are you overexposing via your eye, or using the exposure bar/histogram? If the latter, have you found a sweet spot?
Click to expand...

The camera is pretty accurate when metered give or take a 1/4 of a stop either way. I can expose by eye now. However I have nor determined whether underexposing a quarter or over is the better way to go. It seems like under is too dangerous, lifting in post versus bringing it down gives me strange results.

And when I get to 5DtoRGB it seems like what I thought was going over still had some leeway.

Trial and error: now I can justify shooting trees cars and people to get used to the cam.
 
I just ran some tests outside, mainly to observe the color shift in the camera. Overall, the image seems much flatter after pressing record, and I think a budge to the saturation in post will be a good place to start. Now I need to test under vs over exposing. Didn't I see you commenting that you'll probably stay between 320-800 ISO?
 
DevonH said:
Right now I'm shooting Smooth -2 -2 -1 -2, which is a fairly flat profile. But how can you know if you're properly exposed if the LCD isn't accurate?
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I thought your original post was about color, not so much exposure.

Here's a quote I read from Tom Guilmette on one of his blog posts "When I shoot, whether it’s ENG, off the shoulder, or it’s with the Phantom, I take all color out of the viewfinder. I don’t want color. If you have your camera set up properly there’s no reason to even see color, and for me it’s easier to focus." http://www.tomguilmette.com/archives/2971 That was what I was refering to in my earlier post. Once you know your color settings going in, you really don't have to play with them.

To me exposure is an experience thing. Once you get to know your cam and glass it shouldn't be too hard to hit it every time. Like Kholi said, I believe that with 8bit 4.2.0 cams and h.264 compression you have to keep the histogram up a stop or so so that you don't have to boost in post. Noise ramping seems to be almost exponential with these things if you have to boost. Highlights blow out no matter what and there is no profile that can save them without everything else being black IMHO. By reducing levels in post you can retain shadow detail and have the lowest noise levels and only have the highest highlights clipped.
 
Thanks for the tips hammer. So, in keeping the histogram up a stop, I want to ride to the right, correct? In my tests earlier I had a fairly decent curve riding the middle, granted it was peaking (right into the top of the meter).
 
I bought a Sekonic C-500 color meter and manually dial in the measured color temperature in Kelvin.

8-bit AVCHD color is "baked in" to some degree, so I want to be sure I've got a good color starting point when I shoot.

The interview I shot this morning started at 6300 K ( overcast sky ), then slowly crept down to 6000 K ( clouds were thinning out ), and finished at 5400 K. ( clouds were gone, bounced sunlight lit my subject )
 
I took my GH2 on a shoot today. I was there as the sound mixer but decided to sneak some shots through the day.
I didn't notice this color shift till today. I know this thread is only a few weeks old but has anyone found out new information in regards to the shift?
What it is actually doing?
One thing I have yet to see written by anyone, is the color temp correct when it's not rolling? or is the color temp is correct when it is rolling? or neither?
 
I think it's this: the screen/LCD is inaccurate as heck, and you need an HDMI out to check it. Funny thing is, the camera that I was borrowing WAS accurate, which weirds me out. So my new GH2 (black) has a COMPLETELY different representation of things, and HDMI out to the TVLogic 5.6 looks accurate for what I would peg an 18 grey card white balance too.

Now that youv'e reminded me, I'm gonna see if I can adjust the LCD color, exposure, etc. to match the HDMI signal out.
 
I thought the color shift was only with the GH2 LCD. I don't remember there being a color shift when using an external monitor. I'm currently without SD cards, so I can't test, but maybe someone else can check to verify. If it's both then I would be only a little concerned as you can light or adjust color temp to compensate.
 
Mike, I came home and just plugged it into my hdmi computer monitor and the shift was there when I hit record.
Just trying at this point to figure out which is the accurate shift. When it's not rolling or when it's rolling.


Kholi, are you saying the shift doesn't happen at all on your TVLogic?
I'm actually planning on purchasing a tvlogic tomorrow so that would be good to hear if that's the case.
 
Rippie said:
Mike, I came home and just plugged it into my hdmi computer monitor and the shift was there when I hit record.
Just trying at this point to figure out which is the accurate shift. When it's not rolling or when it's rolling.


Kholi, are you saying the shift doesn't happen at all on your TVLogic?
I'm actually planning on purchasing a tvlogic tomorrow so that would be good to hear if that's the case.
Click to expand...

Sorry, my bad. I meant the shift in overall color. Like my GH2 LCD = three times warmer overall than the HDMI output. So it duped me into thinking that it was accurate, but I had to rewhite balance to a grey card to match what my eyes sawr, and what the other camera was getting.

HDMI is accurate.

THe shift when you hit record is so minor that it doesn't bother me at all, as long as the HDMI signal is showing me what I figured I'd be getting. Just a learning curve me thinks?

Oh, and the accurate one is when it's rolling out to HDMI. That is what you're getting.
 
Hope this is not OT.

What's the most preferred way for a accurate white balance on the GH2?
Auto, Preset, Manual or dialing in the Kelvin?
 
Kholi said:
So my new GH2 (black) has a COMPLETELY different representation of things, and HDMI out to the TVLogic 5.6 looks accurate for what I would peg an 18 grey card white balance too.
Click to expand...

Hi Kholi, which grey card are you using and how are you using it? We eyeball back and forth between the evf and what we're shooting (tweaking kelvin) but more control in this area would definitely be desirable.
 
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