Monitor calibration for on set use

[Jeff Troiano]

I have a Dell U3011 Ultra Sharp monitor, and I calibrate it with a Spyder3Elite. I have thought about bringing this along on shoots (I am not a video professional, simply an indie wanna be geek). I am interested in using this as a secondary monitor for checking lighting setups, and as a directors monitor. When I calibrate with the Spyder, its saves the profile information onto the computer (not the monitor). I was wondering what the best way to calibrate, using the monitors OSD controls, so that it will have a good onboard calibration? Should I use my video essentials dvd, and calibrate like a home theater tv? Would I calibrate with the Spyder, then toggle back and forth between the profile saved on the computer, and try and "eye it" and adjust color controls there? Something else I'm not thinking of?

I know I'm not a professional, but would like to have the best available setup that I am able too. I think I have a great resource in my 30 inch dell, and thought it could be of some practical use while I'm on set.

Thanks for any advice,
Jeff

[Steve Kalle]

Hi Jeff,

How would you connect the camera to the Dell?

One option is the BlackMagic HDLink which takes HD-SDI inputs and outputs via DisplayPort, DVI or HDMI. At least with the DisplayPort, you would get 10bit (assuming your camera outputs 10bit over SDI - FYI, no camera has a 10bit HDMI output) from your camera to your monitor. And yes, the HDLink is capable of driving 30" LCDs. Also, the HDLink allows you to store calibration in it plus it can save custom created 3D LUTs.

For normal adjustments: If you can, output Bars from your camera into the Dell and adjust that way. Remember that calibrating with Bars is for Production whereas calibrating to a color space (ie, Rec 709) is for post production.

I just thought of something: I wonder if your Dell can accept a 1920x1080 signal and display it correctly. Can it display 1 to 1 pixel mapping?

[Jeff Troiano]

I have fed it 1920x1080 signal from my Mac (via hdmi), while I was waiting for a mini displayport cable to arrive. It will add black bars to top and bottom (monitor is a 16:10 screen), so I am assuming it will do 1 to 1 pixel matching. I was going to go out of camera (canon 5D) via hdmi. Into a hdmi splitter, and use the 30 inch for a director/lighting setup monitor. The other hdmi connector will goto an on camera monitor or evf.

[Josh Bass]

"Remember that calibrating with Bars is for Production whereas calibrating to a color space (ie, Rec 709) is for post production."

Can you explain? I thought the idea for post was you calibrate to bars in your NLE (if grading with an NLE). So for example, in the field I use camera bars, in post, I put bars from FCP on the timeline, and adjust to that.

[Steve Kalle]

For post, you need your monitor calibrated to whatever color space you are delivering in. Each color space has different color primaries and different white points. So, for HD broadcast and web, you need it calibrated to Rec 709. And for SD, you would use Rec 601. For Film, you would use DCI and/or a 3D LUT.

For production, you need the monitor to represent the recorded image as close as possible and the HD video is already set to Rec 709 and most broadcast monitors are factory calibrated to Rec 709 and higher-end monitors allow the loading of LUTs to emulate the destination color such as an HP Dreamcolor used on set for the last Chronicles of Narnia with a 3D LUT loaded.

[Brian Tori]

Jeff,

As you are aware, your monitor will only hold a hardware calibration when connected to your computer which holds the profile. When you take the monitor into the field you lose that calibration. This is the reason that using computer monitors are not ideal for what you want to do. However, most computer monitors have a preset called sRGB in the menu. Using this will get you fairly close to the ideal standard. Gamma 2.2, 6500k color temperature, sRGB gamut. For non color accurate puposes such as on-set monitoring, lighting ratios, etc.. this should be good enough for your application. The second alternative would be to buy a HDTV which will have the proper calibration controls such as saturation, hue, contrast, bright, which will allow you to calibrate to bars as normal.

[Josh Bass]

I guess I'm still confused because

a) how do you calibrate to a color space?

For instance, my setup right now is the old school "computer to A/D converter (camera) via firewire, out to monitor via Svideo, RCA, BnC" setup.

Pretend I'm using FCP to do the grade

PS, I'm specifically thinking of footage from a 5D, which as I understand is 601 even though it's HD.

And b) don't you want to know that you're looking at your footage accurately in post in the first place? Seems that calibrating to a color space instead of to something that allows you to know that what you see is what you get (e.g. NLE color bars) are at odds?

I'm sure I don't understand something in this process but I don't know what it is.

[Steve Kalle]

Using Bars for calibration does not set the colors to the correct color space which is why calibrating to a specific color space is required. As I stated before, each color space has specific color primaries and white points, and using Bars to adjust gamma, hue, contrast and such does not set the monitor to the correct color primaries.

FYI, you cannot use FCP's canvas or desktop view for accurate color grading per Apple. With FCP, you must use an I/O card or box to a monitor. With Premiere Pro CS5, as Brian pointed out, you can actually use a monitor connected to the video card for proper color.

Btw, using Bars is really an old way of doing things from the days when everything was SD. For production/field use, Bars is still the proper way for on-camera monitors.

HD video is Rec 709 and most HD cameras record and output Rec 709; thus, you need a monitor calibrated to Rec 709 for post production. SD video is Rec 601 and its odd that Canon uses this for its HD video. FYI, there is a noticeable difference between 709 and 601 easily seen in the reds as I have both 709 & 601 calibrated in my Eizo. When switching between the two, I can easily see the difference.

[Josh Bass]

So if outputting via firewire to an old CRT SD monitor is the only only option right now, can that monitor be calibrated to a color space? And if so, how?

[Brian Tori]

CRT monitors cannot be calibrated to a different colorspace. The colorspace is defined by the phosphors they use. For professional use, this is SMPTE C. Certain LCD monitors on the other hand can be made to emulate various colorspaces. As Steve mentioned, the HP Dreamcolor can be made to do this. Josh, when outputting through 1394 to your CRT, just run bars to the set and calibrate as usual. If you are using a professional CRT you should be good to go. If you are using a consumer CRT your colors will be close but not as accurate.

[Josh Bass]

It's a pro CRT, just wondering what can be done on the post side using the same monitor.

[Brian Tori]

Josh,

When sending your signal through 1394 to your CRT, the NLE will do the colorspace conversion to 601 space. I don't use Final Cut, but this should be what occurs.