I have a HD CRT RPTV that was purchased in 2000 and calibrated in 2005. When it was calibrated the very well known ISF guy said he doesn't clean the tubes because it doesn't make a difference.

Now as you can imagine a 7yr old RPTV would have some dust and it does appear to have a thin layer on all 3 guns. My question is if I use a air gun or perhaps a lens brush to remove it will it alter the grayscale by a large margin? I'm trying to get more light and pop out of my picture w/o having to turn up the contrast. I imagine that if one gun has more dust than the other then yeah it should screw up the grayscale but the dust appears to be equal and I don't see why there would be any significant difference in the amount of dust because its in a sealed chamber.

So should I do it? + - a hundred kelvins I think is acceptable to get more pop and depth.

I have a HD CRT RPTV that was purchased in 2000 and calibrated in 2005. When it was calibrated the very well known ISF guy said he doesn't clean the tubes because it doesn't make a difference.

That is absolutely bizarre. It certainly does make a difference if the amount of dust is significant. It is possible that your set was very clean, and in which case I would agree that it is best NOT to clean the lenses if it is not required. But if you never cleaned the lenses in the 5 years from purchase to calibration, unless you live in a NASA clean-room or something, I would expect there to be at least moderate dust on your lenses that would warrant cleaning.

question is if I use a air gun or perhaps a lens brush to remove it will it alter the grayscale by a large margin? I'm trying to get more light and pop out of my picture w/o having to turn up the contrast. I imagine that if one gun has more dust than the other then yeah it should screw up the grayscale but the dust appears to be equal and I don't see why there would be any significant difference in the amount of dust because its in a sealed chamber.

Yeah, unless you don't clean all three lenses, greyscale should be maintained the same. It's a curious question though, I've never heard of anyone measuring that, but assuming that the dust is basically even on all three lenses, removal of the dust should have equal effects on each.

BTW, you can find good cleaning tips here:
http://www.keohi.com/keohihdtv/experttips/panelofexperts.html

Both Guy and MrBob have good tips there, the others probably do too, I forget. Recommend not using canned air, and be very liberal with the use of lens tissue, always keep fresh tissue on the lens. You'll have a gigantic pile of used tissue by the end, but you don't want to just be rubbing dirt around.

Thanks Chris, yeah there was dust at the time of calibration. I don't think my calibrator does lens cleaning at all. If you want to know who he is just pm me but he is well known. He never said cleaning was part of the price but it was a full calibration according to his website aka the most expensive. Thats why I think he just doesn't do that kind of stuff. He also mentioned that lining the inside with duvetane or whatever its called doesn't do much for black level.

I think he probably only calibrates new sets and a customer like me was unsual. He did a great job with the greyscale because lighting/fleshtones in movies look just like they do in the theatere

Thanks Chris, yeah there was dust at the time of calibration. I don't think my calibrator does lens cleaning at all. If you want to know who he is just pm me but he is well known. He never said cleaning was part of the price but it was a full calibration according to his website aka the most expensive. Thats why I think he just doesn't do that kind of stuff. He also mentioned that lining the inside with duvetane or whatever its called doesn't do much for black level.

I think he probably only calibrates new sets and a customer like me was unsual. He did a great job with the greyscale because lighting/fleshtones in movies look just like they do in the theatereMost calibrators who have been around for awhile certainly do offer cleaning of optics - but they do charge extra for that service (my extra fee for that & refocusing lenses is $75). If your cal was 2 yrs ago, your tubes have likely drifted a bit and the difference in gray scale due to cleaning will likely be less than the drift with age anyway.

Does a year 2000 CRT warrant getting it recalibrated?

I'd definitely look at getting a new set. My CRT lost so much light output by year 4.

If you've not ever cleaned the optics since you got the set, you'll also want to take the lens barrels off and clean the coolant cups, as well as the bottom lens. All sorts of dust and small light attracted bugs tend to crawl in there. It will make an immediate difference in your display. Just be sure you are removing the screws for the lens barrel, NOT the coolant covers! If you can see the mirror, it should be cleaned also, but you need to be very careful. If you smoke in your house, the smoke tends to cloud the optics as well.

I live in what I would call a high dust area. I clean my optics about every 6 months.