Color Space Confusion

[Steve Yager]

I'm using a Dreamcolor monitor, and I've had it set to rec.709 when grading RED footage in Redcine-x. Is this correct? Will the 709 color space in the monitor display the color correctly as I'm grading it? I feel confused about color space and how I should set my monitor for grading RED footage since there's no Red Color 3 setting of my monitor, obviously. Would love some advice.

 

[Alex MacLean]

What are you using to send the signal out? Are you coming dvi off the rocket out of rcx?

 

[Steve Yager]

What are you using to send the signal out? Are you coming dvi off the rocket out of rcx?

DVI straight from the video card (ATI Radeon HD 5770)

 

[Blair S. Paulsen]

There are several issues involved here.

For starters, your "video" card puts out a signal that is inherently different than a proper video source.

The Dreamcolor is an unusual beast in that it is both a computer monitor and a legitimate (IMHO) video monitor, most computer monitors are unable to credibly mimic a traditional video monitor. This is due to design choices made to enhance text readability, control costs, maximization of compatibility across more resolutions and refresh rates, etc. Typically computer monitors are too contrasty, have skewed primaries and poor saturation linearity. Because the Dreamcolor was co-developed with Dreamworks I consider it a hybrid.

Just because the same device can do both doesn't mean that feeding it a DVI signal out of a computer will offer an accurate representation of what your audience will see on a regular TV set. Like many of us that use the Dreamcolor for color critical work, I always feed it via SDI into an SDI to DVI/HDMI converter as SDI is a "proper" video signal source.

In terms of rec709 vs P3 or other presets on your Dreamcolor, the first question is what your deliverable is. For DCI finish (digital theatrical) you will want to work in P3 and I would suggest you do an actual calibration for P3 rather than using the preset. That said, if the monitor itself is well calibrated the presets should be pretty close. For a web deliverable you could just use "user full" but be aware that many of your viewers will see a much different image as the device they are viewing on is unlikely to have the gamut, bit depth or contrast you are seeing.

IF buying a Kona card or the like is not in your budget/plans and your primary deliverable is for TV, then using the DVI into the Dreamcolor and using the rec709 preset should get you pretty close.

Cheers - #19

 

[Steve Yager]

Thanks for taking the time to write that, Blair. Much appreciated. The funny thing is I just sold my Kona LHi thinking I didn't need it. Maybe I'll pick up a Blackmagic DeckLink 4K. Would that suffice? And I'd need a SDI to HDMI converter for the Dreamcolor correct? I just read a white paper on the DCI P3 preset for the Dreamcolor and the adjustments that need to be made. For others interested, you can find it here: http://h20331.www2.hp.com/hpsub/downloads/Understanding_LP2480zxDCI_P3Emulation.pdf

Going out to DVD and Blu-ray should just be rec709, correct? Thanks again for all the help.

 

[Marc Wielage]

Yep, what Blair said.

How did you calibrate the monitor? Like any display, the presets on the Dreamcolor do not magically put you in the right color space, gamma, contrast, or black levels.

Once calibrated, the Dreamcolors aren't terrible, but like many LCD monitors, they only really work for people sitting right in front of it. It's a problem for color correction, especially if there's more than 2 people watching, due variances in viewing angle brightness and density.

For Rec709, I think the higher-end 20- and 30-series Panasonic plasmas are a better bet. They're being used all over LA and NY for network TV delivery and home video projects. The Dolby monitor is much better, but costs about 15 times more. But again, calibration is absolutely critical.