[ojosch]

Hi all. Sometimes I try to act like I know a lot about stuff (I do in some cases), but the truth is I know very little compared to many of you guys about CRT projectors and stuff in this category due to a lack of experience in this field. I basically know what I've learned from reading things here, and reading the complete Sony installer's manual, and tinkering around with my own 1272. But all in all I would classify myself as a noob to CRT still.


I have a problem that I've tried doing a search on (couldn't find the cure), a problem which I believe is probably in the adjustment and caliberation of my 1272. I'm running it in 4:3 w/ my standalone processor (4:3 mainly because of my s-video TV source), But when I slap in a DVD (also an s-video source through the same processor as for TV source which outputs RGBHV to projector), the picture winds up being widescreen as per the ratio of the DVD I'm watching. Now, when the scene playing is a dim scene, all looks great. But, when a bright scene comes on, the black bars above and below the widescreen image get way too bright (seemingly too much) which makes the main image in the middle look slightly washed out. I originally thought maybe it was reflection of the screen onto the ceiling reflecting back onto the screen washing it out, so I hung a black sheet onto the ceiling and it was still just as apparent. The other thing I noticed that made me think my settings are dinked up, is if I put on some medium dark goggles (from the shop for my cutting torch), and looked into the projector lenses, I noticed that when the bright scene comes on the whole raster gets brighter including the area outside the widescreen image (the area of the black bars). It's as if when the scene gets bright, the light bleeds into the darker areas that should stay black. I know this projector is supposed to have 20,000:1 contrast ratio so I must just have something out of adjustment. It does have a notable amount of this light bleed while watching fullscreen 4:3 TV source as well (light leaks into areas that should remain dark), but it's not as apparent or annoying since it kinda blends into the image (as there are no black bars in the image to distract you from the image in that mode).


I got the clamp set to H/C,


the gains are at: R=185, G=170, B=220,


and the bias is at: R=148, G= 99, B=174.


Projector contrast is at 85


Projector brightness is at 55


I realize every projector will have different calibs, but does it sound like I'm way off judging from those numbers? How can I effectively make it so the area outside of the image area of the DVD movie stays dark, because it sure doesn't act like 20,000:1 to me. If it is, and mine is normal, then I'd hate to see what it looks like with and LCD projector with only 1000:1


This is probably an easy question for many of you since a lot of you are professionals, so what am I doing wrong in my caliberation? The screen looks very dark during a commercial blank when the screen goes black, so I think my brightness is set low enough. And if I'm watching movie credits, the white letters look nice and vibrant white with good contrast to the blacks, it's just when something bright comes on that the balance is all whacked. Could it be my processor doing it? Seems much darker on the black borders all around when I'm running my HTPC into the RGBHV, but still does it to a lesser degree confged that way. Still just seems like it's more in the projector settings to me, but is there any reason why the HTPC seems a little less exaggerated?

 

[Niels Nielsen]

Dont know, just reacted on your contrast at 85, isnt that a lot ?

 

[ojosch]

The Sony manual sais to start out at a baseline of 50 brightness, and 80 contrast to make many of the adjustments, so I'm technically only 5 over on the contrast, but at any rate, I tried it at 80 and it still has the same syptoms as I described before. I'm baffled, since I am not an expert and don't know where to start. Is there a good tutorial somewhere on the www that talks about correctly checking/setting white balance and greyscale? I read all the stickys and seen the CRT setup article, but it doesn't cover that, just the mechanical aiming, and focusing, etc. and that's not my problem, I'm aimed and converged quite well, and my colors DO look great, I just wish I could set the amount of light that bleeds into the black bars on bright scenes. All three tubes are creating this effect, not any one over another


Anyone else want to take a stab at it?

 

[Drew Eckhardt]

Quote:

Originally posted by ojosch But, when a bright scene comes on, the black bars above and below the widescreen image get way too bright (seemingly too much) which makes the main image in the middle look slightly washed out. I originally thought maybe it was reflection of the screen onto the ceiling reflecting back onto the screen washing it out, so I hung a black sheet onto the ceiling and it was still just as apparent.

This is normal. Projection screens pick up _all_ light whether from the projector, the room, or the projector reflected off the screen and then off the room, furniture, people, etc. The effect will be less if you paint the entire room flat black, switch to black carpet, black furniture, and stop wearing light colored clothing.

Quote:

How can I effectively make it so the area outside of the image area of the DVD movie stays dark

You'll need masking if you want the "black" bars to stay that way with an image on the screen.

Quote:

I know this projector is supposed to have 20,000:1 contrast ratio so I must just have something out of adjustment.

While you may have that on-off contrast ratio, contrast ratio within a projected image in a real room may be no better than 150:1.


Your HTPC may appear better than the processor because the image is darker.

 

[Vibe]

I have a 1271 with 120" diag showing on the wall right now (screen arriving this week, can't wait to see the difference). Even on the wall I have my contrast set to 65 and it looks great. I think Sony says to start

at 80 on contrast to help with all the convergence but then you need to

turn it down when completed. If I ran mine at 80 or more I would see the same problem as you. When I get the screen set up I will probably get to turn it down even more (55 - 60) as the screen will be much brighter than the wall I am currently using.


My suggestion, turn the contrast down to 70. If that doesn't look good, then I think you may need to look at the whole room set up. How far from the screen is the projector? how well is the light controlled in the room?

You really need a very dark area, the lumens on our Sonys are very low.

I had to get dark curtains and cover doorways to other rooms and halls in my apartment to get a good picture. A streetlight shining through the window of the kitchen (which has crappy blinds) caused problems with

the picture until I covered the kitchen doorway with a dark blanket.


I am also a newbie with CRT but a simple thing to try and see if it works.

 

[Curt Palme]

It's possible someone has played with the G2 controls. HAve you got the main manual that tells you how to set the bias and gain without test equipment?


Also, look into the tubes to see if you're getting light reflections, or if the bars at the top and bottom are actually emitting light, which they're not supposed to be.


Curt

 

[Don Rombach]

One thing that is fundamental that you seem to be missing is adjusting the contrast basically increases the light output. If the picture is washed out, adjusting the contrast settings will have little effect.


Sounds like much of your problem, particularly the "picture being washed out" in the brighter scenes is that the brightness is set to high.


As Curt said, the G2 and bias settings may be off, and may need to be adjusted. But a brightness setting of 55 is the more immediate, quickly correctable problem.


Try using a contrast setting of 75, and a brightness setting of 40-45. You should see an immediate improvement of b lack level.


What you need to achieve is a balance of black level (brightness). To little brightness results in "crushed "blacks. Dark scenes that are indeed dark, but lack shadow detail. To much brightness, and black becomes gray, resulting in a washed out picture.


As others have said, the darker the room the better. But light spill will always keep the black bars you're speaking of from ever being completely black.


One the most effective DVD's for calibrating contrast and brightness levels is the movie, Fifth Element.


For brightness adjusting there are two scenes. One is there is a group of men in black uniforms walking. There are round knobs protruding from their shoulders. Pause the movie and adjust brightness so you can make out the shadow the knobs cast, while keeping the black uniforms black. Shortly after is a scene of the same uniforms on a rack. Use this scene to verify your previous adjustment by looking at the shadow detail in this scene.


Later in the movie there is a scene where there are men in white shorts and shirts. Use this to adjust the contrast setting. Adjust the contrast so you can make out the shadow detail in the clothing while getting the white as bright as possible. Then back off the contrast a bit (for tube longevity).


Sorry I don't recall the chapters these scenes are in off hand. Perhaps someone can chime in. I watched Terry use this method setting up my pj. Works great, less hassle.

 

[matrix]

Try assigning the DVD 16:9 format to it's own memory location and use the image blanking function to eliminate the phosphor activity above and below the image.

 

[ojosch]

Quote:

Originally posted by Curt Palme It's possible someone has played with the G2 controls. HAve you got the main manual that tells you how to set the bias and gain without test equipment? Also, look into the tubes to see if you're getting light reflections, or if the bars at the top and bottom are actually emitting light, which they're not supposed to be. Curt

First of all, thanks for all you guys' helpful answers, as I'm learning a lot from your suggestions.


When you refer to G2, is that the same as gain, or is G2 the controls that are covered up near the electronic beam focus on that little box (to the right of the blue CRT)? Because I've only tinkered around with the gain and bias settings on the service controls of the remote while in serviceman mode. I just ordered the Avia setup DVD to officially be able to check some of these adjustments with more accuracy, because right now, I can only test it to video picture which can vary a lot, source to source.


I can't really tell for sure if it's caused from light reflection back onto the tube surface near the tube/lense, or if the light is actually coming from the tube phosphor being emitted by the gun, but whereever it's coming from, the tube surface of the black bar area is definitely emitting too much light the way I had it set.


As per Don Rombach's post I turned the brightness down to 45, and contrast to 75, and that helped a whole lot, but now the picture is just very dim overall. And it's in a totally light controlled room that is pitch dark when the projector is turned off. Don't get me wrong, it is still totally seeable, but when I compare it to my big screen RPTV upstairs it's just too dim for my liking. The image has better detail on these lower settings, but I wish it could just have more brightness to it without washing out.


Perhaps I just need a higher gain screen? Because it seems really good if the whole thing was just brighter at this same level of output from the projector. Awhile back, I was thinking about upgrading to the DaLite High-Power so I wouldn't have to drive my projector so hard because I know I like it brighter that most, but I don't know if that 2.8 gain screen will make it brighter, and not cause hotspotting? I've posted about that too on the screen forum, and it seems nobody has tried High-Power with a CRT. Tons of DP guys have but it'd be nice to hear from a CRT user who has tried one, before I buy one.


I AM going to try the 5th Element movie (thanks for the suggestion) and see if I can tweak this thing better, and I'm also going to play w/ the Avia disc to see if I can get the other things (like G2, WB, and Greyscale) all dialed in better.


Is there a good tutorial on setting the Grayscale calibration (with possible blue gun defocusing) somewhere here?


Also, what is the correct procedure to set G2 and white balance correctly? I'm still unclear on these couple of details

 

[ojosch]

Quote:

Originally posted by matrix Try assigning the DVD 16:9 format to it's own memory location and use the image blanking function to eliminate the phosphor activity above and below the image.

I considered this idea too but my satellite 4:3 and my DVD signal both come into my video processor on the same s-video input (switched beforehand by my A/V receiver), and my processor DOES have a mode for 16:9 mode, I'll have to see if it'll save the 16:9 mode as a different setting in the projector for the different modes/resolutions. I'll look into it, because a couple weeks ago, just for kicks I DID move the top and bottom blanking to fit the widescreen temporarily and it did seem to help some. But would that 'more definite' line from blanking it there help it to have higher tendency to burn a permanent line into the phosphor over time? The other potential issue w/ true 16:9 is that my wife doesn't speak perfect english yet and so I always turn on the caption of DVD movies to show Spanish dialouge while we listen to the movie in English, but the problem is that the CC'ing dialouge is usually always in the lower black bar.

 

[Don Rombach]

Ojosh,


Good to see you're making some progress.


On the overall brightness thing.


First of all. The primary limitation you have is 12xx pj's are not the brightest crt to begin with. 600-650 peak lumens.


Aside from insuring the g2 settings are correct, and bumping up the contrast a bit, the screen and physical set up is the next place to work on.


Be sure you are using as much of the raster as possible while staying within whatever wear pattern you may have currently on the phosphor. This will help a bit both with overall brightness and sharpness.


The biggest thing is what size and gain of screen. Smaller is brighter.


The high power will work with a crt if you are not ceiling mounted. It is retro-reflective. The brightest would be a curved screen.


I kind of went through the same issues you are dealing with. Started with a 1272. Was determined to have a 8' wide screen. Got all into this home theater thing and sprung for a Silverstar screen. Good, but still not happy with the brightness (and sharpness). Wound up upgrading the pj to a g70 (1200 lumens). That did it.

 

[ojosch]

Yeah, I guess it does kinda seem like I have to REALLY drive this projector hard in order to feel like it's bright enough for me. I tried watching 2 movies last night with it set lower (contrast/brightness), and I couldn't handle it. I just can't get into the movie as well, unless the brightness seems to be comparitive of real live. For example, if it's a sunny day in a scene on your movie, I like to have the intensity of the screen seem to be like a real sunny day. After all, that was the whole point of big screen right? To help you to feel as though you really are there, living it- with them.


Anyways, I guess I have a couple questions for you still (to Don). You got the SilverStar, right? Did you get the 6.0 gain one? And that still wasn't enough w/ your 1272? And you also talked about those curved screens too. Aren't they like 12.0 gain or something? And I suppose that the curved screen would bring the gain closer to my RPTV set upstairs, right? Or perhaps RP is brighter than FP? Any thoughts on that?


How much brighter do you think going from 120" down to 100" get you? Would that even be a significant gain in intensity noticable to the eye?


I could go bigger on image using the blanking adjustment. I notice when the projector is on the 20 min. warmup cycle (no blanking, w/ full white screen), the full raster is almost a foot wider than my screen on each side (maybe 1.5-2 ft total increase), and extends around 6 inches on each end of the top and bottom (total of 12 in taller), so I guess I could scoot the projector closer to the screen, re-focus and converge, then expand the blanking and RGB size to fit more of the open raster? Is that all there is to changing the throw distance? I would need to check in the manual and see if that will require spacers in the lenses to re focus.


I'd like to try and get this 'ol 1272 dinosaur dialed in to see if I can maximize it's potential enough to 'get by' for now, because I really don't have it in my budjet right now to get a G70 or better. Besides, this 1272 is paid for, and it only has 1600 hours on it. Maybe after I get done with my move and get all settled in at the new place and my bank acct has more in it

 

[Drew Eckhardt]

Quote:

Originally posted by ojosch Y How much brighter do you think going from 120" down to 100" get you? Would that even be a significant gain in intensity noticable to the eye?

44% more Ft-l. Noticeably brighter and punchier.

 

[Don Rombach]

As you can see from Drew's reply screen size makes a significant difference. similarly, the throw distance also effects overall brightness. You may be able to decrease the throw distance somewhat. Since you are using a 4:3 screen you will wind up pretty close to pj calc specs however. The best way to maximize the image is to center the green, and expand the size to within 1/8' of the phosphor edges (at the corners). Use that size setting to move the pj until the screen is filled. To use this much phosphor will likely require shimming the red and blue tubes to avoid running the image over the edge on these. If you are sticking with a 8' wide screen, this may not be necessary as that is the default size screen for the 12xx. The idea is to center the cross hairs on the screen to the green without using much if any electronic adjustments for the R&B centering. This helps with convergence stability as well as allowing maximum phosphor usage.


The Silverstar is rated @ 6gain. Most opinions I have read feel that the effective gain of this screen is more like 3.


The curved Vutec is 13 gain (I think). Note gain is not proportional. IE 13 gain is not 13 times as bright as 1 gain.


Both are rather expensive screens. The highpower is worth looking into if the pj is floor mounted. Also, if you are adventuress, you could try the DIY route for a curved screen.


As far as getting a picture as bright as a RPTV, consider this. Your 6x8 screen is 48 square ft. A 50" diagonal RPTV is about 10 square feet.


Smaller is brighter.


With the 1272, silverstar combo I was not displeased with the brightness level for watching movies. However, trying to watch football games in the dark with My drunk @ss friends was a challenge. With the higher lumen G70, I can turn on enough light in the room where everyone can see what they are doing, and still have a great picture. For movies however, it's lights out.

 

[ojosch]

Quote:

Originally posted by Don Rombach As far as getting a picture as bright as a RPTV, consider this. Your 6x8 screen is 48 square ft. A 50" diagonal RPTV is about 10 square feet.

Not to mention, my big screen TV set also has an RP Fresnel/lenticular screen. And I already priced one of those out for 120" size and they want $10,500, wousers! Oh, but I forgot to say, shipping is free w/ that




Anyways, I got some homework to do and some experiments to perform, so I can come up with the highest bang for the buck. I might experiment with a combination of 100" screensize, more phosphor exp, and a DaLite HP, which could likely get me enough brightness without having to run my CRTs wide open. That, I would imagine, would help the tubes to last longer too. At 1600 hours now, I still can't see any wear on the tubes yet w/ projector off looking in w/ an LED penlight. But I CAN tell the area outside of the blanking has just a tinge more of a cooler white than the white inside the noraml image area (w/ projector on during warmup- viewing screen). Hopefully this wont show up to a distracting degree if I increase my phosphor area?


Thank you all for your help.

 

[Niels Nielsen]

Not very relevant maybe, but with my D50 I have a 16:9 1.0 gain 84 " screen. Around it a 4,5 " border, black filt wrapped.

Settings on D50 is brightness 55, contrast 50, screen normal, ABG on, color 6500.

DVD player is Philips dvd 963SA, settings are brightness +2, contrast +1, gamma -1 as I recall.

The projector went from PJCalcs recommendation of 271 cm distance to 256 cm. Have a set-up more or less as recommended by Don Rombach.

I choose the small screen size because of recommendations not to go too big, and then have more punch in the picture, plus the screen size made my center speakers fit perfectly under the screen.

The picture at 271 cm wasnt very interesting, a bit washed out and weak. Now I have deep colors, beautiful blacks and the picture really packs a punch. I have no reference to compare with but feel its quite good.

My head is normally at the rear end of the projector so I feel the picture is large enough for me. Of course its not cinema size, a wow factor, but looking at the quality of the picture I am content (dangerous word to use..)

All I need now is an approval of the set-up from a pro, looking at rasters and so on...

 

[ojosch]

I found a used Vutec 4800 curved 100" screen w/ like 13.0 gain for $295 (a new one from Mounts and More costs $1200). I'm getting it shipped to my new address where I'm moving to in Utah, so I'm going to give that a try. I think it will allow me to turn my PJ gains, brightness, contrast way down, which will solve a whole bunch of problems at the same time. Now that I had gotten to thinking about it a little (really picking my brain), when I was little, I remember a friend of my Dad's who used to set up CRT projection setups for a living used to tell me that CRT projectors were supposed to use this type of screen if you wanted the tubes to last a long time.

So when it gets there, and I get over there, hook it up and test it, I will post back with my results. The guy I bought it from sais you can leave the lights on in the room and watch anything just like you would with a TV set.