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29th January 2004, 20:09 | #1 | Link |
budala
Join Date: Oct 2003
Location: U.S.
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Preview on PC vs TV
Has anyone been able to get the colors on their PC to look reasonably close to a standard TV?
I measure the gamma on my TV (at factory settings) to be about 1.6. This is probably due to the black level being cranked up. I can change alot on my monitor, and I should be able to get reasonably close to my TV settings (excpt maybe sharpness and interlace). Has anyone ever tried to adjust their monitor to match a TV? Should I just buy a studio monitor? |
20th February 2004, 03:58 | #2 | Link |
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It can't be done. With NTSC the R-Y resolution is only 60 line and the B-Y channel is only 40 lines, now thats not per inch, but horizontal width of the screen. Pal is less. There is no G-y but it is made by decoding analog and combined with the detail comes from black&white signal. Here is where PAL is better, British PAL being best.
The color phousphors are different in the CRTs. This is why you must have a analog monitor connected to your PC to do color and gamma adjustments. Richard photorecall.net |
20th February 2004, 17:35 | #3 | Link | ||
budala
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Quote:
Here is the most ligit discussion of this I have found so far. This is a piece of it in response to makeing a combo TV/PC monitor. Quote:
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21st February 2004, 00:50 | #4 | Link |
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Also the standards vary between CRT manufactures, plus the demodulation is not standard. It's suppose to be 90 degrees, but that doesn't allow for good shin tones, so most demodulate somewhere between 105 ~ 110 degrees, which reduces the need to adjust the (TINT-HUE) control with a trade off or very orangie reds. Same thinf in PAL where there is no hue-tint control.
So broadcast moitors are great to use because the P22 phospher is exact and demodulion angle is 90' It would be great if these were easy to obtain. But I still use those 15 year old Commadore S-Video monitors Richard Last edited by rfmmars; 21st February 2004 at 01:36. |
23rd February 2004, 22:07 | #5 | Link |
budala
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Thanks again...
So ... A standard TV does not look like a NTSC monitor (not same phosphers and hue is off, color temp is different, etc) ? A PC CRT does not look like a NTSC monitor because of interlace, sharpness, color temp, brightness? It looks like you can get PC monitors with P22 and color temp controls. I'm sitting at a compaq with 9300, 6500, 5500 temp controls. Not sure about the phosphers. I Assume one wants to do color correction on an NTSC monitor because it matches a standard, whereas a TV and PC monitor do not match a standard (unless you know the specs of a given PC monitor). So the point is the adjust to a standard not to a subjectively 'good' picture. |
24th February 2004, 01:42 | #6 | Link |
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Hold on...... I think I confused you a little. Yes you could use a TV set as a monitor, but if you could get one of those older 14" Commadore monitors, they have a very sharp trace, perfect white balance and gamma tracking, and s-video in with audio.
A studio monitor will have exact P22 phosphers that are set down in NTSC standards. You can adjust your PC monitor for the correct tempeture, but you are dealing with computer RGB, not NTSC R-y B-y. I been around for a long time in this business, and back in 1954 the first color TVs RCA CTC100 gave a very precicse color rendering, but the lights almost had to be turned off in the room. Over the years the CRTs were made brighter, but tv companies wanted to make it so you didn't have to adjuct the hue control for each program. So what they did was to increse the demodulation angle from 90 degrees to somewhere around 110 degrees, so no longer do we see that deep red color. Only onprojection set do they come close. On your CPU monitor set it somewhere between 5600 and 6500 K A tv that has a video in is better than trying to balance on a computer monitor. The standars are pretty loose. What I do is play several commercial DVDs and set the controls for best picture, and that is my working standard. Richard |
24th February 2004, 21:36 | #7 | Link | |||
budala
Join Date: Oct 2003
Location: U.S.
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Quote:
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-------------------- I really do appreciate this discussion. I am trying to learn the topic of color correction. I've written a vdub plugin that shows me histo/wfm/'hot pixels'/ and working on vectorscope. Past 'flying by instruments', I am also trying to get a handle on how I can tweek by eye. I think the commodore tip was great. I'm now looking for one. I need to get past learning/coding into more seeing and doing. Comming up with a reasonable viewing method has been holding me back. Thanks |
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6th March 2004, 09:07 | #8 | Link |
the dumbest
Join Date: Oct 2002
Location: Malvinas
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It could be perfectly done.Matrox Parhelia comes with an utility to adjust the PC monitor to look just exactly as a video monitor (talking about gamma and colours).
The problem is you would have to deal with a lot of specs from the video monitor and from you PC monitor and then make a color profile or make your own customized LUT to get the result. It is much the same Kodak does for its Digital Intermediate systems, which use normal PC monitor that after using the correct color profiles give you exactly the same look as positive projection copy. Anothe item to take note is that colors not only change because of the PC monitor but also the video card you are using, so your LUTs will depend on the combination of these two things. Hope this helps. BTW, I've been using LCD monitors to check the video in a feature film recorded in DV ( for going to 35mm) and they work perfectly. The so called studio monitor aren't so standard as they say.Take two from different manufacturers and you'll see what I'm saying. Last edited by morsa; 6th March 2004 at 09:10. |
9th March 2004, 22:42 | #9 | Link |
budala
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@morsa
Thanks for the comments. It sounds like it is doable, but probably not worth it. I imagine, you would have to have a colorimeter type of device to really match monitors. I expect this is what studios use. I found the best practical advise to be to use a set of commercial DVDs as a standard and match to them. Do you think this would work? I mean, matching gamma and hue/saturation buy viewing select commercial scenes and my work on a reasonable quality CRT PC monitor. |
10th March 2004, 02:46 | #10 | Link |
the dumbest
Join Date: Oct 2002
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Not exactly.It would be better to take a color rendition chart, measure the values for each of their colors, make a version for video with the standard you are going to use (CCIR 601 or 709)and only then compare the two images and try to calibrate acordingly.
BTW I still believe it would be a better way to make a custom lookup table, I mean I guess it is the only suitable solution. If you have seen an LCD projector, may be you have noticed I has a really bad yellow color rendition, that is correctible with a lookup table, cause you can take just the yellow range and add a little bit of red without changing any other color. About the DVD way, yes it would be right mostly for the gamma and saturation part, but it won't work correctly for the color balance. You will end up with many differences between some selected color aside you could match gamma characteristics. The same happens with photographic film. For example your digital image has a nice light blue and may be other colors.You record it to film and ,what happens? You discover your nice light blue is now many times darker than your original and other colors are exactly the same as they were in the digital master, why? Because film acts different for every color regardless of its luminance.The same happens between every CRT tube. When you use a professional color calibration system what you get is a software that will give you a lookuptable that compensates your output image for every color. Last edited by morsa; 10th March 2004 at 02:56. |
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