View Full Version : CRT amateur color calibration
sshambar 04-12-07, 06:54 PM I've been reading this forum on and off for awhile and have used lots of ideas posted here to refine my CRT setup. One exception, though, is color calibration, ie correct RGB G2/drives to correctly represent "white," and correctly display the IRE levels (10 is 10% of white, not somewhere between 3 and 25% because I'm using the non-linear range of my drive).
There appear to be two camps here... those who fork out a sizable percentage of the price of a CRT to have it calibrated by a professional (even flying them in), and those who eyeball their setups.
Is there any reasonable middle ground? I bought a nice sound meter at Radio Shack to balance my speakers, but I don't really know if there's any color calibrators for CRT projectors this side of $15000.
Are there any "homebrew" or "cheapskate" options out there short of "it looks white to me!" I'd almost think it'd be possible using a digital camera (properly configured) and photoshop; but then I'm I geek and I think I can do everything myself -- which I realize in brief moments of clarity isn't true.
Scott
garyfritz 04-12-07, 07:01 PM There are lots of inexpensive measurement options out there for the enterprising tweaker. E.g. you could get a Spyder2 for about $80 and use the free ColorHCFR (http://www.avsforum.com/avs-vb/showthread.php?t=737550) software to run it and interpret the results. Or you could use a simple spreadsheet. (http://www.avsforum.com/avs-vb/showthread.php?t=587485) That's what I'm using so far because my old colorimeter doesn't play with HCFR.
I mess with my setup so often, it would be stupid to pay someone $1k or whatever to tune it to perfection. Next time I changed something, I'd screw up the perfection, and there's $1k out the window. I'd much rather learn to do a good job myself, even if I don't do as well as the pros.
I use the THX Optimode material as its designed for an end user. I actually use the TOY STORY 2 disc as I feel the OPTIMODE on that disc is easier to use / see then whats on some of the newer discs. ( contrast set up is cut and dry on this disc )
It is designed to be used with your EYES nothing else and I think by understanding what and why you are making some of the adjustments on the disc's you can acheive extreamly good results.
I just saw a professionally set up system and compaired what I saw whith my system using the same material ( Fifth Element ) and to me it looks like I have the same results on my screen. I honestly think my black level is blacker then what I saw as some of the star feilds on the pro calibrated set up looked lighter then what I have my system set up as. Granted I was looking at a 9" set up and I only have a 7" so maby the light output on a 9" being more then a 7" has that look.
I would love to see how close I am by eye with an electronic colorometer and see if and how much improvent a colorometer would make if any.
sshambar 04-12-07, 08:07 PM There are lots of inexpensive measurement options out there for the enterprising tweaker. E.g. you could get a Spyder2 for about $80 and use the free ColorHCFR software to run it and interpret the results. Or you could use a simple spreadsheet. That's what I'm using so far because my old colorimeter doesn't play with HCFR.
Thanks Gary. I read a few of the threads linked off the spreadsheet thread above (wow, I'm out of my depth!) and most people appear to be using the Spyder2TV or Eye One. However, all the units I see appear to be for RPTVs or direct view CRT/LCDs. Are there any low cost colorimeters for CRT/LCD projectors?
Scott
garyfritz 04-13-07, 12:19 AM The Spyder2 is supposed to be fine for projectors, and most others hat are good for direct-view CRTs. Just set it up at the screen, pointint right at the green CRT.
I'd be less sure whether it's OK for an LCD projector. A CRT sensor is a tristimulus sensor -- R G B -- and it expects to be looking at an R G B source. An LCD bulb has a completely different spectrum. I'd be fairly surprised if a CRT tristim sensor gave correct readings for an LCD projector.
Gino AUS 04-13-07, 12:26 AM You can use the Spyder2 for CRT pj's.... but I'd recommend looking at the DTP-94, as it can read sub IRE30 better
You can buy used Minolta CA-100 colorimeters off ebay for cheap, cheap, cheap. Even more common are the TV2150 colorimeters. These are real, professional colorimeters, and while they may not be super recently calibrated, they will provide you with MUCH better colorimetry than you can possibly get "by eye".
I've bought half a dozen colorimeters from ebay, never paid more than $180., and my current one is a Philips PM5639, one of the best meters ever made, still sold for many thousands of dollars 'new'.
Gino AUS 04-13-07, 08:56 AM Ok, so I searched ebay for your Philips PM5639 and it comes up as $1500... how is that $180?
I didn't say that YOU could buy one for that amount TODAY, RIGHT NOW.
I meant the one that I currently OWN, I'm not selling it, I'd never be able to afford to replace it....
Being an auction site, there are a wide variety of sellers and items. The seller with the Philips PM 5639 on there for $$ big dollars is obviously knowledgeable about what they are and how much they are worth. You would need to find one being sold by someone who DOESN'T know that, or perhaps doesn't CARE.
I bought an analyzer card for a CA-100 that I got from a guy in Poland via ebay. I paid $35. for the analyzer card, which has a retail cost of around $1000. The guy was happy to get $35. for something he didn't know anything about...
stefuel 04-13-07, 05:17 PM I have the 2150. It works well above 20 IRE. That's it's crap-out point. The box is useless if it does not come with the matched sensor.
Chip
garyfritz 04-13-07, 05:24 PM Ya, I have a 2150 too. I can read 20 IRE (just barely), which is generally 0.1 ftL. If the blacks are crushed too much, then 30 IRE is about as low as it will go.
Soapsuds 04-13-07, 07:31 PM I'm using the SyderII Express. Toss the software and use ColorHCR as suggested above.
Works OK but weak on the low end. The ColorHCR is very informative software late lets you calibrate as you go.
Ken Tripp 04-13-07, 07:54 PM Thanks Gary. I read a few of the threads linked off the spreadsheet thread above (wow, I'm out of my depth!) and most people appear to be using the Spyder2TV or Eye One. However, all the units I see appear to be for RPTVs or direct view CRT/LCDs. Are there any low cost colorimeters for CRT/LCD projectors?
Scott
Both the Spyder and Eye One sensors work with LCD/LCOS/DLP pj's and I would assume also work fine for a CRT pj as you should be taking the reading off the screen and not directly from the projector.
The Eye One Display2 is the best of the cheaper colorimeters, better accuracy and reads to much lower IRE.
Despite what some people may say you can't set grayscale, colour temp or gamma "by eye", but don't use a spreadsheet, the free ColorHCFR software and their DVD is the easier and better way to do this.
Ken
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