CurtPalme.com Home Theater Forum

[winny]

Parted the renaming two tubes from their housings today which I intended to use with new scheimpflug housings. So far so good, until I held up the tubes at an (un)favorable angle. There is wear on the blue tube and a hint on the green. Previous owner had low ceilings and hence the projector mounted flush at zero degrees with a characteristic wear pattern as a result. As always it's hard to capture. Let's just say they are more pronounced in real life than what shows up in the picture.

What are my options? Keeping within the wear area will just mean unfavorable mounting position and premature wear on the other tubes (red is like new, green has a hint of 16:9 wear which is only visible when it's out of it's housing and held at the correct angle against the light so I would say an 8) which to me is shooting myself in the foot since I will deliberately be raising running costs and decrease resolution.

Also, I'm that annoying person who writes letters of complaint to the managers of cinemas when the convergence is off, 3D polarization images don't match up to the millimeter, the masking is off and similar so I will for sure notice color differences in the image if there is a edge. There is a small difference though in that the cinema costs $10 an hour and the CRT is about $0.05-$0.5, depending on how long I let the tubes go, so I expect perfection at the movies.

If I run a full blue image and adjust the image to cover all of the surface area minus minimal safety area, will it blend out? Compensate by using a negative image in my HTPC/scaler?
Learn to live with it and it will blend out over time?
Tune a negative image on the blue tube and run it over a few days to wear the rest of the phosphor to the same level?
Suck it up and get a new tube?
Other option?

[CasetheCorvetteman]

Nothing wrong with those tubes...

[CasetheCorvetteman]

Buy three tubes and get three housings free!!

[km987654]

Those tubes are fine just keep the image in the wear zone and you won't notice it.

[winny]

[CasetheCorvetteman]

From what i can see you wont have an issue, you cant use the whole face!!

[winny]

I was able to adjust the 808s mounting position to get much further to the edge than this, but perhaps it's within practical limits. The difference in available surface area between ideal and the 4:3 limit for this is about 44% (or 69 % area left).

Dedicating the 1209 for 16:9/2.35 use only does not help either since this helps maximizing the width with no round tube corners to worry about.

None here who successfully worn a tube into shape by using an inverted image? You all paid up instead?

[Curt Palme]

Just an FYI, the pix from the website above showing tube wear had significantly worn tubes, not the very light wear that you show in your tube pix.

Put the tubes in the set you're going to use them in, and max out the phosphor area to past the wear points. Set the projector up floor mounted first, and see if you can live with the slight wear. I have a feeling you can. If not, move the projector back so that you're within the wear area, and use it that way.

Unless you're putting 6-10 hours of use on the set per day, even running the set within the wear area should last you a good 5000-6000 hours (if not more, depending on your contrast setting), and chances are the set will fall apart before the tubes are toast.

[Curt Palme]

Just an FYI, the pix from the website above showing tube wear had significantly worn tubes, not the very light wear that you show in your tube pix.

Put the tubes in the set you're going to use them in, and max out the phosphor area to past the wear points. Set the projector up floor mounted first, and see if you can live with the slight wear. I have a feeling you can. If not, move the projector back so that you're within the wear area, and use it that way.

Unless you're putting 6-10 hours of use on the set per day, even running the set within the wear area should last you a good 5000-6000 hours (if not more, depending on your contrast setting), and chances are the set will fall apart before the tubes are toast.

[digitalayon]

Tubes look pretty good to me.....FYI.....my company makes the 3D polarizers for Real D. If they fail to calibrate correctly, yes you will have a headache.

[winny]

Oh, I will have a headache from the 3D alone. No matter how much they have spent on the 3D and production (Gravity), it's not worth it to me. I sweet-talked to the cashier lady which was about my age quite attractive too and got a second pair of glasses, cut it open and swapped left eye for right eye between the pairs to make 2D goggles. 3D was gone but the convergence problems where still visible since the right eye picture didn't hit the masking. Took out the other pair to verify and the convergence between right and left eye was off by perhaps 50 mm in the top part of the left hand side. Color convergence was off too. Freakin' multiplex crap!

Perhaps should mention that I'm an ex-cinema mechanist. You know, the old stuff with 70 kg 35 mm film loaded into huge things which didn't ask for DRM clearance, had no anthropomorphic paper clips to guide you or didn't allow you to screen the movie to spot problems before 600 people came into the auditorium. The good old days...

[ecrabb]

That's a very slight level of wear. I'm guess it will probably only be noticeable in fairly solid backgrounds like clear blue skies or when you're watching something like Ice Age with lots of light, solid backgrounds.

I wouldn't mess with wear-matching; you probably have at least as much of a chance of making the problem worse as you do fixing it.

SC

[winny]

[ecrabb]

You're amongst a pretty anal bunch, here. I know how you feel. Once I burned a damn ammo-counter into the corner of my G70, I saw it all the time. Drove me nuts, and even soured me on CRT to some extent. Partially my fault, but also a significant disadvantage to CRT.

Your 3-step approach sounds reasonable to me. Definitely try it and see how it looks before you get too worried about it.

SC

[Ile]

[winny]

Good heavens! That's nasty. Any pictures of the tubes that produced this? Any attempts to even out the wear?

[Ile]

[Curt Palme]

[Curt Palme]

[ecrabb]

You're funny, Curt… However, I'll just point out that at some point not in the not-too-distant future, you'll be like the horse-and-buggy advocates. Yeah, the car did have some disadvantages, but overall they were worth the trouble compared to the alternative. Pretty sure we're already there for like... I don't know... 98% of the population.

SC

[winny]

[CasetheCorvetteman]

Lesson here is stop exploiting the Chinese and manufacture locally

Just use the tubes and stop moaning, they are fine. Use of a smaller area will help you get better corner focus, both optically and electronically. Your astig will also be better.