Posted February 03 2003 - 05:33 AM
| WHAT??!! Nils, why didn't you tell me you're an ISF tech? |
If I'd know that, I wouldn't have paid Steve Martin to come down from Dallas to calibrate my RPTV last July.
OK Hank, its time for your annual Alzheimer's check
Speaking of which, I'm letting the cat out of the bag and letting you all know Hank's "39th" B'Day was last week so give him a virtual high five.
Hank, if I recall we only recently met when you had Steve come down to do your calibration and I didn't even know about it until after you had it done. Regardless, while I am more than capable of doing a complete ISF calibration (setting grey, gamma, chroma, and convergence) my certification only came about when I accepted the position as VP at CST (Custom System Technologies) and was going to be managing a group of ISF calibrators. It was important for me to be able to fully understand what they had to accomplish out in the field so for that reason I took the complete ISF course with Jim Burns. While I did very well in the course, I would be foolish to think that I was capable of doing an ISF as precise, or certainly as quickly as a professional ISFer with years of experience, after all, much of it is subjective and a good ISFer will adjust his calibration to meet the specific needs of each client.
Another problem with DIY ISFing is the cost of the calibration equipment. My training was done on various Sencore calibration equipment which at that time retailed for any where between $2,000-$10,000. On the other hand, I also did some calibration exercises with the use of only an optical comparator, or in laymen terms, a light bulb. There is a German company that makes a 6500D K bulb such that a calibrationist can visually align it to the center of the image and adjust the greyscale to match the bulb. It is hardly precise, but it can get the job done such that only someone armed with a color analyzer could probably tell the difference. The good news here is that the bulb only costs about $300, probably less by now.
I should also point out that many people interested in HT have the impression that only CRT based display units require ISF calibration - and this is simply not true. Digital projectors may not require any convergence, but convergence is secondary to what an ISF calibration does. The heart of an ISF job is setting the proper color of grey, and frankly I have yet to find a digital projector that came from the factory with a greyscale of 6500D. Sure, the settings menu will likely have an option for "Color Temp" and one of those options will "say" 6500D, but I'll be willing to put down a cash bet that if someone checked it with a color analyzer it would not measure 6500D.
In Dave's case his FP's (LT 150?) greyscale is clearly not set at 6500D thus causing him to notice the green push. Without even testing his FP I'd guess his greyscale is at least 5500 or less. Ideally you would want to be within 50 degrees of 6500D, but as mentioned before, video is subjective, and a good calibrationist can make fine adjustments that match the needs of the user.
Also even digital FPs will drift away from 6500D over time, but yearly calibrations for even CRTs is unnecessary. Convergence on the other hand should be done yearly, but this is something that can be done by the owner with a little patience and practice. Most modern CRT RPTVs now have convergence memory such that you only have to converge once! From then on the set remembers precisely the settings for a perfect convergence and will maintain that convergence for the lifetime of the TV - so again, lets not scare unsuspecting would be RPTV owners into thinking they have to spend money and time constantly tweaking their sets - that simply is not the case.
The reason many RPTV sets might not look spectacular is that many people who bought them simply turned them on and never changed the default settings. Just spending a few minutes adjusting the basic picture settings (sharpness, brightness, contrast, color, and tint) in conjunction with an over the counter calibration DVD like Video Essentials or AVIA, anyone could make their RPTV as close to perfection as one can without also adjusting the greyscale and convergence.
Given all that, I'll still say that even if I took an out of the box $2000 CRT RPTV and did an A-B comparison with a fully ISFed $10,000 digital FP, the CRT would still provide a better PQ than the digital FP. The fact still remains that CRT technology, even when not perfectly calibrated, provides the best color accuracy, black level, contrast, shadow detail, and fill factor) all of which are required elements to making a great picture.
As someone who had the option of having a CRT FP, but ended up choosing a digital (DLP) FP, obviously for me the difference in the quality of the PQ was not significant enough for me to make up for the many other advantages that a digital projector has over that of a CRT and that I personally found usefull, but for each person the story will be different, I just don't want anyone to be given the impression that somehow digital projectors can in any way provide a PQ that meets or beat a CRT. This goes for RPTV and FPs alike.
Sorry for the long posts, but I'm just trying to keep it real because I get tired of all the hype and misleading info that gets spread around the HT community. I think it unnecessarily scares would be HT users from buying a technology that could have easily been the best match for them, and the fact is both technologies coexist because they both have their place. I have no doubt that CRT will go the way of Vinyl records, but that day is still far far away, and will only really happen once digital can match the PQ levels of CRT.