HDTV Color Space Question

[Andrew J Hall]

If I have a second PC type LCD monitor for approximate color correction (I know I don't have the money for a professional calibrated model), how do I ensure it is using a HDTV color space rather than the normal PC color space (which has much less contrast) - is it just a question of applying a different color profile to that particular monitor?

I hope this is not too dumb a question. I remember years ago spending a very long time optimizing the color for a 60 minute art video I was making using a PC monitor and then finding that I had to do the whole job again once I tried to display it on a TV since the shadows and the highlights all blew on the TV.

Andrew

[Emre Safak]

It does not quite work like that. What you really want to do is to profile your second monitor (using a colorimeter) and load your profile in your editing/compositing application. This will ensure that WYSIWYG. Second, you want to make sure that the colors are not out of gamut. This should not be a problem unless you manipulated the source footage.

For reference, the HDTV color space (ITU-R rec.709) is approximately the same as sRGB (I think the tone response curve is different).

[Glenn Chan]

Rec. 709 and sRGB differ in the transfer function (which affects gamma).

2- I don't know what methods are good for getting the most out of consumer monitors... usually they have problems that are just solved by the broadcast monitors (the good ones at least; some of the early and low-cost LCD broadcast monitors have problems).

3- What editing application are you using?

[Andrew J Hall]

Thanks for the responses.

I am using Premiere Pro (soon to upgrade to CS3) with Cineform.

I have read that Premiere does not provide for color management - so what color space does it actually use when you are working with HD within the timeline (actually Cineform codec) and looking at the 'monitor' panel within Premiere.

Andrew

[Glenn Chan]

It probably decodes the values according to the Rec. 709 and 601 formulas to full-range R'G'B'. In that situation:
A- You need to make sure there are no video card overlays.
B- The computer monitor ideally should have the same characteristics as a broadcast-grade monitor. This is actually not defined by the standards, but should be similar characteristics to what a CRT does.
Needless to say, consumer computer monitors don't do that by default. For certain displays, you might be able to calibrate it so that it looks similar to a broadcast monitor... eCinemasys did this with the EDP100. But I don't think it works that well and is cost-efficient. In the case of the EDP100, the newer Apple Cinema Displays have some image problems and therefore don't work well. They have also moved into making their own monitors and have abandoned the approach of the EDP100 (trying to calibrate a consumer monitor + implement other processing to make it broadcast-worthy).

*I assume you are on PC/Windows. OS X is different.

2- A consumer *computer* CRT will likely look more similar to a broadcast monitor than a computer LCD or CRT TV. Make sure to turn off any image enhancements like viewing modes.

I don't think it's really ideal though.

3- Probably the most reasonable cheap solution right now is to get a SD CRT broadcast monitor... they are about $600. They are excellent for SD work. It is the best way to monitor SD.

HD-->SD downconversion for monitoring will work as long as the values are being converted correctly (FCP or quicktime has a bug there that you might run into). Don't know about Premiere. Use a 1920x1080/1920x1200 monitor to see HD resolution. I don't know if Premiere can play video 1:1 on such a monitor.

[Emre Safak]

If an application does not support color management, it uses the monitor's native (i.e., unprofiled) color space. I know AE CS3 supports color management, so you might like to do your color correction in that.