Some component output issues

Ted Spencer

Ted Spencer

Veteran
[Previously posted in General HVX section, trying again here]

In very early testing with my HVX (just got it a week ago) I've noticed a couple of thing regarding the analog component (RGB) outputs that I thought I'd compare notes on with others here. In all cases I'm talking about shooting 24f/720p, either pN when recording to P2 or p when recording live into FCP via firewire:

1) Frame rate from real-time camera output: it appears on both my Panasonic 42" plasma screen and my Sony HT75W 17" widescreen LCD (used by numerous others here) that the display frame rate live from the camera is reduced somewhat. A noticeable motion-stroboscopic effect is visible when viewing either of the monitors that is not visible on playback in Mac/FCP after live capture, nor is it visible when playing back from P2 to the plasma or Sony. The same effect is also visible in the onboard LCD.

2) Brightness: the real-time component output from the camera looks absolutely sensational, but seems to be unrealistically bright. It's much darker viewed on the Mac/FCP both before and after capture, and also when output to DVD and viewed on the plasma or Sony. Here's a description of an admittedly quick, informal test I did:

First I connected the component out of the camera to both the Sony 17" and the 42" plasma and adjusted both for a pleasing image, matching color, brightness and contrast to each other as closely as possible. I did this two different ways, using a freeze-frame from an HD source (an HBO movie) on my HD cable box. I plugged both monitors simultaneously into the cable box's component out using 3 y-cables (which admittedly degraded the signal, but presumably did so the same for both monitors) and matched them. I also plugged them in one at a time to make sure they still looked matched after they got their proper signals back, and they did, as well as I could determine given the time lapse between viewings (it was in this part of the test that the "pleasing image" determination was verified, not in the degraded, y-cabled part).

Next I recorded some 24/720p footage via firewire directly into my Mac/FCP rig (Dual 1GHz G4/FCP 5.1.2). It looked much darker there than on the camera's component output to the Sony, which was sitting right beside it, even with the computer monitor's brightness (a 22" Apple Cinema Display) turned all the way up. I then used Apple's Compressor app to create a widescreen DVD ready file at the highest possible quality and resolution settings, imported it into DVDSP and burned a disc. I played it on my Pioneer Elite DVD player back on the plasma screen (via component) and the image was again much darker than the live camera output, roughly equivalent to the FCP/Cinema Display. The Sony HT75W produced similar results.

I do feel that the test setup eliminated the obvious other explanations, such as simply having the plasma or Sony's brightness up too far to begin with.

What I've concluded from this is that at least in practice, the HVX's analog component outputs appear to be unrealistically bright - that the actual image, once captured and played back on other systems and devices is much darker.

To avoid being misled by this, and consequently underlighting a shoot (a mistake you don't want to make with a 1/3" CCD HD camera), I've concluded that I will have to use adjusted settings on external monitors to compensate - settings a good deal darker that what looks right for other playback situations, such as viewing a DVD movie or HDTV. I spent a fair amount of time comparing live componenent output to captured/DVD playback, and came up with some settings on the Sony (it will be my primary shooting monitor) that address this issue, which again, is mainly a matter of lowering brightness (although once I did that some other settings inevitably needed to be compensated). After making the adjustments, I feel I have a workable solution, but it's not ideal. Ideal would be if the live output's brightness matched the other monitoring scenarios, but it doesn't, and there is no provision (that I know of) to adjust the camera's component out brightness.

Lastly I want to mention that I know that neither the 42" plasma nor the Sony LCD are "broadcast-quality" monitors. I don't plan to make hyper-critical decisions on a shoot about color, etc. using them. In that regard, they're a compromise I hope to be able to work reasonably well within. But the brightness discrepancy does appear to me to be something of a different animal...

So the simple question that follows this long-winded explanation is:

Anyone else have this issue?

Thanks!
 
peter orland said:
Mmmmm...interesting. Have you tried the same test using the S Video or composite out?

Pete.
Click to expand...

No I haven't. I'm mainly concerned with HD performance at this point, which is properly viewed from the component outputs only. It would certainly be easy enough to test though.
 
First, it should be point out that analog component video is not RGB, its Y, Pb, Pr.

Second, have you calibrated your production monitor against the camera? You shouldn't have much difference in the luminosity levels if you properly calibrate. One of the reasons to have a production monitor on set is to give you a way of judging the shot (both to avoid missing objects due to the overscan on the camera's EVF and LCD) and to set your lighting levels and ratios.

Learn to calibrate your monitor and most of your problems will disappear.
 
khmuse said:
First, it should be point out that analog component video is not RGB, its Y, Pb, Pr.

Second, have you calibrated your production monitor against the camera? You shouldn't have much difference in the luminosity levels if you properly calibrate. One of the reasons to have a production monitor on set is to give you a way of judging the shot (both to avoid missing objects due to the overscan on the camera's EVF and LCD) and to set your lighting levels and ratios.

Learn to calibrate your monitor and most of your problems will disappear.
Click to expand...

First, yes I do understand that "RGB" in technical terms describes a different interface/protocol than component video. However, component's connectors are in fact red, green and blue, so "RGB" can also serve as an informal shorthand for it.

Second, calibrating the monitor, either "by the book" or somewhat more informally is actually what I'm talking about as the solution. After trying both I found that my "eyeballed" adjustments/comparisons got slightly better results though.

The main issue concerns the HVX's component output luminance level "out of the box" compared to other sources such as medium/high end consumer DVD players, HDTV cable boxes etc. Pretty much all of them that I own are within a certain range of luminance that the HVX is way outside of. Maybe the HVX's level is "right" and all the others aren't, but it does seem to require some unusual settings to get the HVX into the same visual ballpark as the others.

On the other hand, I briefly owned a high-end Sony DVD player (before I exchanged for the Pioneer Elite) that had even brighter/contrastier component output "out of the box", a fault that was commented on by some reviewers. I guess I'm making a similar comment about the HVX (but only in brightness terms) , and wondering if others have found it so.
 
Hey Ted.

I tested it out for myself yesterday at work (component out into a JVC 17" HD monitor, an old PVQ 14'' Sony, a HD plasma and the 24" Dell). Allowing the differences that are inherent in these monitors across the range, I got the same result on all screens as you did - a much higher luminance level between the HVX and the captured Hd from Final Cut or converted QT clip. I also checked the YC and composite, and other than the obvious difference in output, the result was the same (I thought maybe only the component out might be running hot, that's why I asked earlier).

Having said that, I don't think it is all that much of a problem (would be good if it was perfect , but...) after further testing. Putting the colour issue aside for the moment (as that's a whole other can of worms when it comes to on set monitoring) and just looking at the elevated luminance. The HVX's internal metering (shutter, aperture, gain) seems to be spot on in regard to capturing "correctly" exposed images. If you were to try and set the image in the (whatever standard calibrated monitor) to appear exposed "correctly" on screen, you would be at least a few stops underexposed, but, you would also be overriding the internal/or external light meter readings. So for run and gun using the LCD or viewfinder and auto settings I don't see a problem. For controlled shooting you should always light by metering (yes I know, old school film mentality) as it is telling you the facts as far as contrast. Then there's the onboard zebra, which seems to work more than adequately. Then there's your eye, as you can clearly see that the monitor is overcompensating the luminance output over the actual scene levels so... And then if it bothers you enough you could try and calibrate your monitor to compensate, as you have done, which is fine as long as you are only using HVX's and not other cameras that respond differently with that monitor.

Thanks for bringing it up.

Pete.
 
Bars!

Bars!

This is precisely why SMPTE color bars were created and why they are an easily located button on the HVX, so you can use them as often as one often does on set.

Turn on the color bars in Camera mode with the TVs connected and callibrate according mostly to the plunge signal at the lower right.

This link is an abbreviated version of how to calibrate with SMPTE colorbars:
http://www.greatdv.com/video/smptebars.htm

I hope this helps!

-Cody
 
codemancmc said:
This is precisely why SMPTE color bars were created and why they are an easily located button on the HVX, so you can use them as often as one often does on set.

Turn on the color bars in Camera mode with the TVs connected and callibrate according mostly to the plunge signal at the lower right.

This link is an abbreviated version of how to calibrate with SMPTE colorbars:
http://www.greatdv.com/video/smptebars.htm

I hope this helps!

-Cody
Click to expand...

Thanks for the link. This is simialr to other monitor calibration routines I've seen and tried, but it'll make a nice Safari bookmark. For the time being I've got my Sony HT75W adequately compensated for luminance, although I do need to get a blue filter for it to tweak the color. The point I'll stick to otherwise is that the camera's component outputs are *very* hot out of the box luminance-wise, and this could be misleading to a potential buyer or new user expecting a bit more of an "in the ballpark" default. Like I...did...
 
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