What's the best way to monitor HD footage?

[Bill Edmunds]

Pro HD monitors are waaaay out of my budget. That being the case, am I better off using a professional 700 line SD monitor or buying a consumer HDTV?

Also, how do you monitor something like DVCPro HD where you likely don't have a deck to feed the firewire signal through? I assume you need something like a Kona card?

[Nate Weaver]

A 700 line pro SD monitor is still bound by the constraints of an SD signal. Meaning, it will never show more than the 540 lines of the SD signal, albeit very accurately.

You're better of with a consumer HD set if all else fails. An SD monitor will not show you focus problems, nor will it display the colorimetry of an HD signal correctly.

[Jaron Berman]

What is the purpose of the monitor for you? Framing, color accuracy? Is it for the field or the edit? Are you trying to "light to the monitor?" Figure out exactly how you will use the monitor before getting something. This is an area where you absolutely get what you pay for, and there are no cheats. Having done it myself, I know that trying to buy inexpensive band-aid solutions only makes it a lot more expensive down the line when you eventually get a good monitor. If you've been getting by until now without a monitor, then perhaps you can keep doing it until you can afford something that would actually be helpful rather than confusing or problematic. Also, many new monitors include waveform functions which should be considered mandatory for repeatable accuracy. Just my 2c, but 2c earned the hard way.

[Brian Luce]

Originally Posted by Bill Edmunds

Pro HD monitors are waaaay out of my budget. That being the case, am I better off using a professional 700 line SD monitor or buying a consumer HDTV?

Also, how do you monitor something like DVCPro HD where you likely don't have a deck to feed the firewire signal through? I assume you need something like a Kona card?

if you have a laptop u might look into dv rack with hdv powe pak plug in.

some folks have been getting good results.

[Dan Keaton]

"Also, many new monitors include waveform functions which should be considered mandatory for repeatable accuracy."

Dear Jaron,

Could you please elaborate on the above?

How does one use a waveform monitor to ensure repeatable accuracy?

[Benjamin Hill]

Originally Posted by Jaron Berman

...Figure out exactly how you will use the monitor before getting something....If you've been getting by until now without a monitor, then perhaps you can keep doing it until you can afford something that would actually be helpful rather than confusing or problematic. Also, many new monitors include waveform functions which should be considered mandatory for repeatable accuracy. Just my 2c, but 2c earned the hard way.

I think Jaron's advice is excellent, know what you need it for before you buy it. I also think I know what he means by "repeatable accuracy"-

I shot several spokesperson videos against whitescreen, on different days and locations; to key out the whitescreen I had to make sure the white levels were deliberately overexposed to 100% white, while the actor was still nicely lit. Using FCP on my PowerBook (via FW) I used the waveform monitor on the capture window to show me exactly what the levels looked like, in a graphic chart form.

I noted these levels (along with camera details, light positions) and used the waveform to get the exact same image on the next shoot. "Repeatable accuracy" is something I can't get away without having anymore...that's my 2c, also earned the hard way.

[Dan Keaton]

Dear Benjamin,

Thanks for the input based on your experiences.

Your explanation helped me to understand.

Dan

[Brian Luce]

If one wasn't concerned about focus issues, and wanted a monitor for checking lighting and framing and general composition, would a SD monitor suffice? HD monitors aren't in my budget either.

sometimes a bandaid is better than letting the blood spill out on the carpet.

[Dan Keaton]

I have been using a SD Sony 9" CRT field monitor for lighting, color, and framing.

I am in the market for a HD field monitor, but have not decided on one yet.

While I feel that a HD monitor will be a huge improvement, a good SD monitor is good for checking lighting, and framing.

Whether is is good for checking color is subject to debate. I assume for purists, it is not acceptable, but it works for me for checking color balance.

[Brian Luce]

Originally Posted by Dan Keaton

Whether is is good for checking color is subject to debate. I assume for purists, it is not acceptable, but it works for me for checking color balance.

Why is it that sd monitors are supposedly not suitable for adjusting color on hdv cams?

[Dan Keaton]

The following post indicates that there is a difference in color between SD and HD.

http://www.dvinfo.net/conf/showthrea...=HD+colorspace

From a practical standpoint, if your camera downconverts to SD on the fly, then a good SD field monitor is useful.

For critical work, I would want a good HD field monitor.

I hope to get a good HD field monitor in the future. However using a good SD monitor has been helpful in the meantime.

[Glenn Chan]

There's a difference between Rec. 709 HD and Rec. 601 SD and "computer RGB" and "studio RGB". There are some weird formats (and cameras) that shoot HD but use Rec. 601 luma co-efficients, but it mostly doesn't apply.

Rec. 709 and Rec. 601:
Both store color in Y'CbCr color space.
The Y' holds a representation of the brightness / black and white information in a scene. Black level is at Y'=16 and white level is at Y'=235 (for 8-bit formats; 10-bit is different).
Cb and Cr are color difference components that represent color. The legal range is something weird.

Anyways, the formula for forming luma (Y') is:

Rec. 601: Luma (Y’) = 0.299 R’ + 0.587 G’ + 0.114 B’

Rec. 709: Luma (Y’) = 0.2126 R’ + 0.7152 G’ + 0.0722 B’

Note that Rec. 601 and Rec. 709 both use different co-efficients (the numbers in front of the letters/terms above). Given the same R', G', and B' values you'll get different numbers for Y', Cb, and Cr depending on which formula you use. And vice versa.

Color errors occur in either of two cases:
A- You shoot HD and want to view it in SD. Let's assume that your HD camera uses the Rec. 709 formula (it'll use the Rec. 709 co-efficients).

Somewhere along the way, something will decode the Y'CbCr signal and downconvert it. During this process, you need to convert the Rec. 709 colors to Rec. 601 because the luma co-efficients are different. However, a lot of consumer HDTV sets do not do this! So a consumer HDTV set may not necessarily give you accurate color.

B- Some cameras shoot HD but with Rec. 601 co-efficients (i.e. the very first JVC HD camera). If everything else follows standards, then you'll get inaccurate color.

2- Computer RGB stores color in R, G, and B channels (not Y'CbCr). Black level at 0 0 0 RGB, white level at 255 255 255 RGB.
Studio RGB also stores color in R, G, and B (not Y'CbCr). However, black level is at 0 0 0 RGB and white level at 235 235 235 RGB. This is not to be confused with Rec. 601 or Rec. 709!

3- To simplify, I've described four *different* color spaces. There are errors that can occur when converting between the color spaces, so that's something to watch out for.

Some errors are intrinsically unavoidable: When converting from Y'CbCr formats to computer RGB, there will be clipping of the Y'CbCr color space. Y'CbCr defines a much larger range of colors than RGB, including many illegal values and many values with negative R/G/B (which is sort of non-sensical, but can happen with miscalibrated equipment). Some of this larger range does contain useful information... i.e. extra highlight information, especially when white balance is off.

That being the case, am I better off using a professional 700 line SD monitor or buying a consumer HDTV?

The SD monitor is limited in resolution. There are some consumer HDTVs which should be able to show you a lot more resolution? (Maybe the Dell LCD that everyone talks about.)

Color-wise, a consumer HDTV is unlikely to give accurate color for many reasons. A professional SD monitor can do it if your equipment takes into account Rec. 709 versus Rec. 601 co-efficients.

On a limited budget, you may find that accurate focusing + light weight is more important than accurate color.
If you blow the focus, you can't fix that in post. If the back focus is wrong, then you can't fix any of your shots. If you have the HVX200, back focus shouldn't be a big deal since you can't change the lens.

[Brian Luce]

heady stuff guys. So it sounds like Paolo's true color settings should be avoided if you plan shoot in hd and burn to SD DVD for delivery. Are there some nice setting for those of use intending just such a work flow?

[Glenn Chan]

The right way of doing things would be:
A- Use whatever camera settings you like best.
B- When downconverting HD to SD, make sure your program is doing the correct conversion- taking into account the different luma co-efficients.

[Joseph Mastantuono]

Originally Posted by Brian Luce

heady stuff guys. So it sounds like Paolo's true color settings should be avoided if you plan shoot in hd and burn to SD DVD for delivery. Are there some nice setting for those of use intending just such a work flow?

Not necessarily... You just have to make sure your colorspace is being accurately converted.