Color Calibration: Dell U2410 & Matrox mini

slimjimmed

slimjimmed

Well-known member
I am color correcting a 1920x1080 30p documentary feature on a Macbook Pro > MXO2 mini > Dell U2410

I am using the sRGB setting on the Dell's OSD and have turned the brightness down to a suitable level. However, I think that my color space is leaning to the yellow/green.

My skintones seems a little yellow/green when I correct them onto the vectorscope i-line in Color. (They look normal on the monitor when they are above the i-line)

Can somebody help me in suggesting a way to make sure that my hue's on my Dell are more trustworthy? Should I rent a broadcast monitor and run it through the Component or RGB out at the same time as my HDMI Dell signal, and adjust the colors by hand to match an SD referencemonitor?

I also don't know if my color space would be different on an SD reference monitor,in comparison with my HD signal on the Dell? (would I be making matters worse by matching the HDMI HD signal's colors to a Component SD signal?)

I live on Portland, OR and am having a hard time finding a place to rent a tool that will help me dial in my color so that I can have some piece of mind....
 
Yeah good luck- that's not an accurate color grading setup. If you can lay your hands on a proper HD broadcast monitor along with say an AJA Kona card or BMD HD-SDI output card you'll get much more accurate color. These would be easier to rent out of L.A. with shipping- don't know if that's in your budget tho...

Noah
 
I appreciate the suggestion, Noah, but there is no more budget for that. That is why I am using this shaky approach. It's the best I could do in consideration of the budget.

Any thought on the dial-in running side-by-side with an SD ref monitor? Is that not going to work since I have an HD color space?
 
Yeah I don't see how that would help. Best you can do is really tweak your Dell monitor to show accurate colors to your eye with color bars. But that's kinda useless once you leave your environment. Really not a good place to be grading. Maybe it's worth letting the folks know who are writing checks on this thing. You're basically mixing audio with the speakers disconnected.

Noah
 
Well, the Matrox mini has a utility with color bars and blue-only adjustements(hue, chroma, brightness, contrast).

From the field reports, it seems that the gamma on the Dell in sRGB is very close. The only issue is that the sRGB setting drifts a little yellow/green.

I found a Panasonic BTLH-1700 to rent in town, so I am going to try tomorrow and use the Component connection to try and match with my Dell. It won't be perfect, but it'll be better.
 
If you are certain that your Dell is exhibiting a particular color or gamma shift you can try and compensate for it by creating a custom LUT in Color. Basically load a test video, for example a chart, make sure it's well exposed and has the proper white balance, and color correct it until it looks "correct" on your monitor, then save the adjustment as a Color LUT. Then whenever you start a new project you can load the LUT and Color will compensate the image for the Dell.

Of course the whole procedure depends on you having a good idea of what is wrong with the monitor in the first place. Also, be aware that your working environment has a very big impact on your perception.

You can read more about LUTs in the Color manual.
 
Yeah I'd be cautious about overcompensating for a perceived color cast on the Dell monitor. It's like giving into the dark side of the Force- once you start down that path it will dominate your destiny...

Noah
 
I like the MXO2 line, but I'd never use them on computer monitors...HDMI input or no. A good quality HDTV, yes. but not computer monitor.
 
I am not positive it is exhibiting a color cast. I am mostly basing my opinion on the experience of correcting the film thus far. Most of the skin tones hover above the i-line on the vectorscope(not even touching it), and have a magenta cast according to the reading. When I dial the skin tones to the line, they look slightly yellow/green and the rest of the image(non-skintones) has a noticeable yellow green.

So I have been bring them as close to the line as possible without them looking off on the monitor. Sometimes they rest perfectly, but mostly they are above the line.

My environment has some curtains that were as close to the 18% gray color neutral sample as I could find. I am using consumer, 6500k fluorescent bulbs from Home Depot. I know it ain't perfect, but I am trying to make the most out of my situation.

On a side note, it doesn't help me that my 17-inch Macbook Pro with the display(which I have used an EyeOne calibrator on) makes the skin tones look magenta when they are reading magenta, etc.
I cannot help to feel nervous when I see the difference in skin tones from the 2 different monitors. I know I am not supposed to trust what I see on my Macbook Pro, but still.....

So, do you think it will be worthwhile to rent the Panasonic BT-LH 1700 (connected via component throught the Matrox) and eyeball it side-by-side with the Dell(running through the HDMI)?

I know I am grasping at straws, but every little inch will give me piece of mind. The one things I obviously don't want to do is make it worse.
 
Renting the HD monitor and trying to ballpark the Dell towards it is better than nothing, I guess, but you are still fighting an uphill battle. This site has a good piece talking about the problems w/using computer monitors for video work: Color Management and Wide Gamut displays – in a CG Workflow
You also need to take into consideration how quickly the Dell will start shifting away from your 'calibration' and how long it takes the Dell to fully warm up.

One thing you could try is when you rent the HD monitor is grade some key shots from your film and use those as your templates to go off of. For example, lets say you grade one shot of each of your sit down interviews on the HD monitor. When you look at them on your Dell it doesn't matter what color cast they have because you know they look correct on the HD monitor. Save all those 'template' shots into the Still Store (I'm assuming you are using Color) and use them as the basis for the rest of the footage.


Also, monitor calibration devices, like what you used on your laptop,. are geared for print usage and are useless to use for video.


-Andrew
 
Yeah ultimately if you want a professional color grade whatever you're doing with the Dell would need to be redone with a broadcast HD monitor. You're kind of pissing in the wind here... :)

Noah
 
adkimery said:
One thing you could try is when you rent the HD monitor is grade some key shots from your film and use those as your templates to go off of. For example, lets say you grade one shot of each of your sit down interviews on the HD monitor. When you look at them on your Dell it doesn't matter what color cast they have because you know they look correct on the HD monitor. Save all those 'template' shots into the Still Store (I'm assuming you are using Color) and use them as the basis for the rest of the footage.
Click to expand...

Thanks. That's a really good idea.
 
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