@towi "...there is only one explanation that really makes sense: when you shoot video the GH2 switches to studio swing (it remaps the fullswing range into the studio swing range respectively). If the GH2 would utilize the full tonal range (fullswing) there would be no change on the histo and also the image on the LCD would display the same tonal range as in photo mode. Many softwares interpret MTS files as being fullswing..."

Nice try, but while it is an appealing explanation of the LCD's behavior, the evidence proves it be incorrect. After Effects identifies GH2 MTS files as Full Swing Rec. 709 standard for good reason: they actually do contain 8-bit luma values that range from 0-255. Download this short sample video to see for yourself, and compare it with the luma waveform in the Color Finesse screen grab below:

What's crucial, however, is to import the MTS file into a video editor, such as After Effects, that can be set to Full Swing Rec. 709 mode. It will then decode the file without altering the Full Swing luma components. If you instead import it into an editor in Studio Swing Rec. 709 mode, such as Avid, it will automatically remap the luma components to fit within the Studio Swing 16-235 range. (After Effects will do this as well if you set it to Studio Swing Rec. 709 mode.)

towi, given Avid's under-the-hood Studio Space alterations of MTS files, it makes sense why it appeared to you that they were encoded in the restricted 16-235 Studio Space range. But in all seriousness, you've made a number of authoritative claims in recent posts that are contradicted by direct evidence, indicating that your advice and assumptions are incorrect. I'd appreciate it if you'd go back and edit those misleading claims appropriately.

@LPowell

you provide yet another conclusion raised from software behavior (in this case AE). Who cares what a certain software reads from the file.

It's not "LCD behavior" I am talking about... it's the histo I am talking about. Quick and dirty handheld iPhone shots of the GH2's histo. 1: the scene in "finder"-mode which shows the photo-histo... levels go from (almost pure) black to pure white. 2: record mode... the black and white values get shifted (blacks and whites get "compressed"). 3: play mode of the respective shot with RGB histo... levels do NOT go from 0-255. Only levels within 16-235 are utilized.

BTW: technically rec709 video levels always live within a 0-255 signal ... but only the range from 16-235 Y' is actually utilized for image content (exactly what the RGB histo below shows). There is no "color space" or "profile" that cuts off levels below 0-16 and above 235-255 (at least not that I know). This is why "rec709" is a very misleading term. re Avid: again, Avid's import-setting "rec709" simply means: no remapping applied / original levels are preserved - either way wether the original levels go from 0-255 Y' or from 16-235 Y' or from 7-45 Y' or you name it. Obviously AE behaves different in this regard. But again, who cares. The GH2's histos say it all.

edit: Avid's RGB histo of the respective file matches the exact same levels as the GH2's RGB histo. Strange, isn't it? I think I have to re-think my workflow ...

cool - so be it.

Tried this patch this morning for MJPEG timelapse of sunrise. Congured frame rate in ptool to 2FPS. Set shutter to 1/2 second. Very pleased with result. Problem was I was only able to record for 40 minutes (1.86GB) onto 64GB Sandisk Extreme Pro card before recording stopped. No error message. Just stopped recording. Footage is fine. Has anyone else experienced short recording times with MJPEG at 2FPS?

@duartix Thanks for the tip. Look forward to 2.0

L O L .

@theojo

HOW DID U GET THAT SCREENSHOT on p.7... thats lil wayne!

@Siddho The GH2 outputs 16-235 within a 0-255 space. Also, in reference to all the general 'adjustment' discussions, IRE is NOT RGB.

720p60 crashes on SanDisk Extreme Pro 45MB/s cards, too, manual exposure, manual focus with Panasonic/Leica 25mm D. To address the 720 issue, which setting should I start with?

@CurtisMack. You can increase the value of the quantiser for 720p. Originally, LPowell had it at 18 in Flow motion 1.1. Then he changed it to 20 in Flow Motion 1.11 for failsafe. If yours is still failing with 20, then increase it to 22. However, as you increase the quantiser value, you reduce the resolution and bit rate.

@lpowell

you are right of course. in Vegas choosing a 32bit float full range project decodes the mts files to linear range (0-255) and choosing a 32bit float or 8bit vider range project (2.222) decodes them to studio swing (16-235). but judging by the massive hit which my CPU takes when working in a linear range project Vegas is actually expanding the 16-235 levels to 0-255. also, every other program which i have used to view those mts test files (of a black image recorded with the lens cap on) show the black level to be around 16 and not zero!

why would otherwise the in-camera histogram also jump upon recording to around 16? that must surely also be a pointer that the GH2 is using ITU709?

is there any way to objectively judge the cameras levels bypassing how certain programms decode thsoe levels?

@Siddho When working in a linear mode it would actually be expanding it to a float range of 0-1. What it should be doing is taking the 16 as zero and the 235 as 1. So your RGB values would resemble the red green and blue numbers below the viewer in this screen grab. those numbers are the average of the values in the red marquee.

@Stray Yes, please download the MTS file that I posted last week at the top of this page, it contains the smoking gun you're looking for. As I've pointed out, however, you must verify that your editor is not surreptitiously converting the file's luma components to fit within the Studio Swing 16-235 limits. That built-in conversion is what has been causing the confusion as to what's actually encoded within an MTS file.

Your point about IRE levels not being technically applicable to RGB levels is of course correct. In an ideal workflow, the notion of a "7.5 IRE Setup" would remain a videotape/broadcast adjustment added to NTSC analog output signals that would never encroach into the digital domain. The reason I use IRE terminology is because that's what NLE waveform displays use to label their luma charts. "7.5 IRE" is also an unambiguous way to refer to the Studio Swing black level offset, whereas "black level at 16" is only correct for 8-bit color spaces, which have quickly become obsolete. (For example, the reason that Pedestal adjustments do not cause the posterization you mentioned is because there are no significant round-off errors in an NLE's internal 32-bit color space.)

Basically, what my recommended pedestal adjustment does is crush the noise and artifact-contaminated bottom end of the sensor's range into solid black. The luma components that lie just above that threshold are legitimate image details and the pedestal adjustment fades them gradually, rather than raggedly, into black. When you then boost the gamma, you get smoother shadow gradients as a result. (There is sometimes however a saturation issue with dark shades that I'll try to find time to illustrate in a later post.)