Do liquid-coupled projectors require special maintenance or periodic examination?

Are they generally as trouble-free as non-LC projectors?

Is the image they throw head and shoulders better than non-LC projectors, or are the differences quite subtle?

Thanks.

To me it's subtle. You get no haloing, the corner focusing can suffer very slightly though. No more maintenance required than non LC sets.

'cept for the need to check the bellows of a LC chamber for signs of large expansion, save for a glycol spillage.

I don't think it's subtle at all. A haze is removed from most images, it's not just halos.

But no, no more maintenance, once the bellows are checked before installation.

LC prevnets/reduces reflections off the internal lens surface. This reduces the reflection from striking back on the CRT face. If reflections occur when you have both hi apl and low apl scence, it seriously lower the ansi contrast and some case you can even see a localized reflection/halo on the image.

I too think it's more than subtle...but I think if you have light colored walls, perhaps it's effect is far less noticeable.

You better look for leaky chambers and potential Fungus growth from abosorbed water. These 2 things are not uncommon and can make for a nightmare scenario. To say they are no less trouble free than AC sets is misleading. Sure, if you get a set that's been freshly re-tubed and re-filled with fresh coolant they should be just fine, but a 10 year old LC machine has a lot of potential for problems.

I just replaced a Marquee 8500 (non-LC) with a G70 (LC). While the 8500 was still on the ceiling, I set up the G70 on the floor and did some quick comparisons. There was obviously MUCH MUCH less halo -- bright objects on a black background had a very clear halo on the 8500 and basically none on the G70.

BUT: I honestly could not see any improvement in "haze," depth, 3-D effect, or anything like that. A G70-owning friend helped me set it up, and he agreed it was almost impossible to tell any difference between the two projectors. I was pretty severely disappointed.

(And Ben, I have dark walls, ceiling, and floor, so that's not it.)

For some reason the G70 seems to have a gamma around 2.1 - 2.2, which may be the cause. With a gamma that low, light levels are higher at all video levels, especially the low IREs. So I may have replaced the non-LC "haze" of the Marquee with the low-gamma "haze" of the G70. If I knew how to adjust the gamma on the G70 I'd do it, but I don't know how. So I have an LC projector that honestly looks no better than my Marquee.

For some reason the G70 seems to have a gamma around 2.1 - 2.2, which may be the cause. With a gamma that low, light levels are higher at all video levels, especially the low IREs. So I may have replaced the non-LC "haze" of the Marquee with the low-gamma "haze" of the G70. If I knew how to adjust the gamma on the G70 I'd do it, but I don't know how. So I have an LC projector that honestly looks no better than my Marquee. that's a bummer Gary, I was hoping there would be a better outcome for you that just "no Halo's" :( IF you added the full latest MP mods I'm sure the 8500 would easilly beat the G70. The real tough decision is still ahead of you, buyng a Moome HDMI card but for which machine :confused:

Gary,

that's an interesting point. In my many gamma experiments, it's clear that a slightly different gamma will also introduce a haze to the picture. I would like to conduct a similar experiment with 2 projectors at the same time and see what benefits there may be.

I would guess then that you would keep the Marquee, no?? I love the Marquee film-like image...not as sharp as an NEC, but it really does look like film!

I had a PGXtra and was able to get at least a 5% benefit by masking the unused tube face as well as unused portion of the lense which faces the tubes. Made a difference and if I get another AC unit, I'll do it again....

Ben

Dragan, I wouldn't bet that an MP-ized Marquee would beat the G70. The G70 is already a lot sharper than the 8500. Maybe the MP mods would improve the video chain in other ways, but I don't know if an improved 8500 would beat the stock G70.

Plus since MP mods would mean I'd have about 2.5x more invested in the Marquee than I do in the G70, it's pretty darn hard to justify. I may decide to go back to the Marquee but I can't see MP mods in my future. Just too much $$.

If I could figure out how to adjust the gamma, the G70 might spank the 8500 "haze-wise." Dunno. But since nobody seems to know how to change the gamma, it may be a moot point.

that's a bummer Gary, I was hoping there would be a better outcome for you that just "no Halo's" :( IF you added the full latest MP mods I'm sure the 8500 would easilly beat the G70. The real tough decision is still ahead of you, buyng a Moome HDMI card but for which machine :confused:

Jumping in on this thread since it appears about options and halos, etc. I have an 81110+ Marquee and have ordered the Moome external box - so that decision is already made and it will support various replacement projectors. (except I got the vga/dvi-d version so no BNCs)

So raises an interesting question re MP mods or going with an LC projector (probably 9 inch version)

The mods are fairly expensive (last time I looked around $1k) and would not do away with halos, and I have a light colored ceiling (multi purpose room anyway)

Thoughts on MP mods versus upgrading to an LC projector, given that I already have the Moome input coming?

My opinion: by far the biggest improvement you could make would be to cover the light ceiling / walls. Reflections from those light surfaces are going to do more damage to your PQ than haloes or other issues. If you can't paint, consider hanging some black cloth or something like that. It will make a HUGE difference. The bang-per-buck is MUCH higher than any other option.

My walls/ceiling are dark purple -- and yet I can still see quite a bit of reflection off the ceiling/etc. I'd probably benefit from black cloth on the ceiling but I haven't gotten around to it.

Do you like contrast or sharpness?

Sharpness - MpMods
contrast - LC projector

So raises an interesting question re MP mods or going with an LC projector (probably 9 inch version)
The mods are fairly expensive (last time I looked around $1k) and would not do away with halos, and I have a light colored ceiling (multi purpose room anyway) Thoughts on MP mods versus upgrading to an LC projector, given that I already have the Moome input coming? Assuming the same tube size (8" tubes) I would have to heavilly weight the decision towards MP mods vs. simply going to 8500LC. Now if the choice is stock 9500LC in excellent condition vs, MP8500AC I would have to go for the 9500 short term and add the MP boards later on down the raod.

Do you like contrast or sharpness?
Sharpness - MpMods
contrast - LC projector It's not really that simple, MP mods improve both sharpness and contrast (low level black detail) as well as reduce back-ground noise, wider color pallete, higher bandwidth, etc.

I've never seen 'em...but now I have to see 'em.

I think Chris N here in Ottawa is using MP boards...I will scrutinize them and see what I think.

Ben

I've never seen 'em...but now I have to see 'em.

I think Chris N here in Ottawa is using MP boards...I will scrutinize them and see what I think.

Ben

I am :) Let me finish doing a rough setup on my projector and you are more than welcome to come over and take a look.


Chris

Gary, you haven't even got it set up properly.

Give it some time - on some scenes you can't see a difference, usually the bright demo scenes. On others it's quite obvious.

I compared my XG before and after LC, same projector. And then I could compare my XG LC to my Xtra instantly with out-of-sync-pic mutes. The difference is there, they added it for a reason.

Mark

I know, I'm impatient. :) But other than the 2.1 gamma, I think most of my setup problems are related to convergence, mech setup, etc. I wouldn't expect any of those issues to affect the things that LC is supposed to affect. Maybe the whole thing will suddenly snap into "oh wow" once I get it all together, but...

My opinion: by far the biggest improvement you could make would be to cover the light ceiling / walls. Reflections from those light surfaces are going to do more damage to your PQ than haloes or other issues. If you can't paint, consider hanging some black cloth or something like that. It will make a HUGE difference. The bang-per-buck is MUCH higher than any other option.


Understood - and my walls are very dark red. But I have been pondering a removable black cloth in front of projector on ceiling (theater doubles as a guest room so I can't go dark on the paint). Looks like the best current improvement

Assuming the same tube size (8" tubes) I would have to heavilly weight the decision towards MP mods vs. simply going to 8500LC. Now if the choice is stock 9500LC in excellent condition vs, MP8500AC I would have to go for the 9500 short term and add the MP boards later on down the raod.

Thanks - will wait for a little and see how I like the Moome box before doing either

Oh, I should add that my room is a dark flat purple - and yes that made a big difference.

I did this years before getting the XG LC.

You better look for leaky chambers and potential Fungus growth from abosorbed water. These 2 things are not uncommon and can make for a nightmare scenario. To say they are no less trouble free than AC sets is misleading. Sure, if you get a set that's been freshly re-tubed and re-filled with fresh coolant they should be just fine, but a 10 year old LC machine has a lot of potential for problems.

Well, that depends on the brand.

Marquee = Possibly fit fit new bellows, check for "fungus" & clean housing, new coolant.

Sony = Check expansion chamber and add new coolant (based on Azzad's experience)

NEC = Check expansion chamber, but otherwise no maintenance required. Old coolant is indistinguishable from new coolant. This is based on me diassembling 6 used NEC LC tubes - completely toasted tubes as well. The only one I know of leaking was done by VDC.

Ampro = ask Chip, I have NFI

Barco = Ask Kal/Dave/etc, I have NFI

So the answer is yes and no.

I just replaced a Marquee 8500 (non-LC) with a G70 (LC). While the 8500 was still on the ceiling, I set up the G70 on the floor and did some quick comparisons. There was obviously MUCH MUCH less halo -- bright objects on a black background had a very clear halo on the 8500 and basically none on the G70.
BUT: I honestly could not see any improvement in "haze," depth, 3-D effect, or anything like that. A G70-owning friend helped me set it up, and he agreed it was almost impossible to tell any difference between the two projectors. I was pretty severely disappointed..

Dragan, I wouldn't bet that an MP-ized Marquee would beat the G70. The G70 is already a lot sharper than the 8500. Maybe the MP mods would improve the video chain in other ways, but I don't know if an improved 8500 would beat the stock G70..
I'm not following you. First you said your stock 8500 was "impossible to tell any difference" from the G70. Then you said a G70 was "lot sharper" and a modified 8500 wouldn't beat it? Am I misinterperting something? Obviously if they are that close in stock form then Mike's highly modified 1080P video chain would tip the balance no?

Gary,

that's an interesting point. In my many gamma experiments, it's clear that a slightly different gamma will also introduce a haze to the picture. I would like to conduct a similar experiment with 2 projectors at the same time and see what benefits there may be.

I would guess then that you would keep the Marquee, no?? I love the Marquee film-like image...not as sharp as an NEC, but it really does look like film!

I had a PGXtra and was able to get at least a 5% benefit by masking the unused tube face as well as unused portion of the lense which faces the tubes. Made a difference and if I get another AC unit, I'll do it again....

Ben
I would like to hear more about masking the unused tube face. What did you use to mask it and how hot did the material get? I am currently working on a lens flapping mod that will allow unlimited adjustment. This sounds like another step to improved picture. The one thing that I am concerned about though is heat buildup. I am also considering the light reflections relating to any changes I make in the materials within the assembly as well as the air curculation.
Larry

I'm not following you. First you said your stock 8500 was "impossible to tell any difference" from the G70. Then you said a G70 was "lot sharper" and a modified 8500 wouldn't beat it? Am I misinterperting something?No, I just wasn't clear. When we did the A-B comparison, we didn't see any difference in **shadow detail**, contrast, etc -- the differences I would expect from LC. The G70 was noticeably sharper even though it was a quick-and-dirty on-the-floor setup. I'm sure I could do better, assuming I ever figure out how to work the damn thing.... :rolleyes:

As for the masking effort...I just taped some pieces of black felt with black electrical tape...it certainly wasn't a professional job, but improvements were noted.

Ben

I too think it's more than subtle...but I think if you have light colored walls, perhaps it's effect is far less noticeable.Yep. I think that's the big thing. I went from an AC to LC unit a couple of years ago and the difference when you have good light control, good gamma, is not that subtle to me. Especially on scenes with both high APL (high brightness) and low APL. A good example is the flyover in the first few minutes of Star Wars Ep 4: A new hope. Big difference to me.

Kal

No, I just wasn't clear. When we did the A-B comparison, we didn't see any difference in **shadow detail**, contrast, etc -- the differences I would expect from LC. The G70 was noticeably sharper even though it was a quick-and-dirty on-the-floor setup. I'm sure I could do better, assuming I ever figure out how to work the damn thing.... :rolleyes:
well , I hate to pile on but it looks like the Moome sony HDMI cards are also sold out?:( hopefully you can snare his new external box if you plan on sticking with the G70. :)

What did you use to mask it and how hot did the material get? I am currently working on a lens flapping mod that will allow unlimited adjustment. This sounds like another step to improved picture. The one thing that I am concerned about though is heat buildup. I am also considering the light reflections relating to any changes I make in the materials within the assembly as well as the air curculation.
Larry


Strange as this sounds, the tube faces do not get hot, you can check this by removing a lense, then fire up your pj and run an image for about an hour...touch the tube face...no heat!
As far as air circulation, I wouldn't worry about that either.
One trick I use, is to seal the back of the Lense assembly to the "C" element, this keeps dust and dirt from collecting between the tube face and the C element...been doing it for years.
On the XG it's simple, just go to Home Depot, buy a $3 roll of 1/4" round foam weather stripping, then remove the lenses and install the weather strippng in the machined groove. The lenses are now sealed to the tube face...Make sure to clean everything first.

No Doubt, Gary's right, painting your walls a flat dark color is probably the most important thing you can do for PQ. Just realize even a dark flat will still reflect some light, and that reflected light will be in the color that you pick.
Joe Kane suggests 18% gray, which is what I used on all walls and the ceiling (I think he suggests flat black on the screen wall, which I still may do)
This color can be found in camera shops, on a card they use to set aperture. It is neutral so reflected light doesn't change gray scale at the screen.

For myself, I found the move from AC coupling to LC to be quite noticable, especially in dark scenes with just a couple points of light. I couldn't go back to non-LC.
In days gone by, I used an HTPC with TheaterTek, and when not in use, the TheaterTek logo would bounce around the screen (black screen, white logo) when I saw the logo's halo go from large and very noticeable with my AC'ed XG, to much smaller and maybe 1/3rd as noticeable with my first LC'ed XG, I was hooked...and as I said, once you realize that, you can easily see it in dark scenes that have a couple points of light.
Since this has to do with the physics of the density of the mediums the image light must pass through (as in, air/glass VS Fluid/glass) you can't get this contrast advantage any other way. I would think Mike's mod's would be even more noticeable on an LC'ed unit.

Thanks for that KennyG This will help me with the design of the infinate lens flapping mounts. I am going to do some experimenting with tube blanking as well.

I recommend to change your LC coolant every 5 years as it tends to yellow or go bad. The LC units are tend to yellow because of the metals and hoses ( 1209) tend to leach out into the coolant.

I Typically see large increases in picture quality with very old LC units after a coolant change.

People with 1209 units will need to put a bead of Silicone RTV ( use the black ultra sensor safe oil resistant from autozone) around the crt base.

Drain the 1209 crts and reseal by putting a thick amount around the the crt base where the casting is close to the CRT. This was later re-designed in the 1209s and 1209 because it typically falls apart and leaks. When I re-sell a unit I reseal the CRTS and refill.

You dont have to cut the old one out just drain because the pressure will keep the new sealant from sealing correctly.

Greg

Are there any special precautions that should be taken when shipping an LC projector - particularly when shipping via unpressurized air cargo?

No, not if the tube doesn't leak currently.

Mark,
I have had my XG since 2000 new. Do I really need to be concerned with crcked tube due to pressure build up and yellowing as well? I hate to do any major screwing with my XG.