[redcorvette_85]

Ive gotten my projector up and running now and its projecting a decent picture up on my brown heavly textured wall, but I have finnally had a little time to figure out the rest of my setup and had a few questions. Couple things about my set up, I have it floor mounted under a coffee table and its been retubbed recently, my guess it's under 1000 hours because I can barely see a 4x3 outline on just the blue crt if I look really hard. Ambient light is pretty much controlled, but not perfect because its a multi-purpose livingroom/ht and theres the WAF factor so I cant go to crazy.


1. First the screen, I asked this in the screen forum a few days ago, but got no response. I am a returning adult student so my budget is limited atm so from what Ive looked at and read about I was thinking of getting a dalite 72x96 spectra screen. Since that is a pretty big image size I wanted to get the 1.5 gain to brighten it up some, should that work well?


2. What is a good resolution to run my projector at? I have been looking at getting a centerstage CS-HD and was thinking of runing everything at 1080i, is that to much for my projector to handle and still look good and is that a decent low end scaler?


3. I quickly hooked up my hd cable box from the bedroom to see how it would look and I got a really strange image. It streched the 16x9 image to 4x3 height and squished it in on the sides some. Is that from having it set up on 480p resolution then changing to 1080i or could that be my transcoder I have an older Audio Authority transcoder 9a62 that is only rated for 480p. I dont quite get the memory blocks on the projector either, does each resolution have to be completley setup and converged to get it to work?


4. Every once and awhile I like to play video games on my xbox and have thought about hooking it up to my projector, but dont want to burn the tubes at all. How long is to long to play it on a projector?


5. I have been doing all the setup myself, but eventually once I finally get all the parts togehter I have been thinking about getting a pro to come over and do the convergance on it. I am in the seattle area, bothell to be exact and I have noticed there a a few guys in my area on the boards. I am just curious what the going rate would be to do a full convergance so I can set aside some money for that eventually


Thanks for all the help you guys have given me so far I have found myself on this site almost everyday now for the past 6 months since I got my first video only projector, I am definitly addicted

 

[MadMrH]

My opinions as follows....


1. I just upgraded my 801s and I used a 1.3 gain screen and all was fine - I worry about high gain screens and dont think they are really needed.....People also mention colour shift with the higher gain screens....


2. 1080i on an 800! it wont do 1920x1080, its sweet spot is 800x600, I ran my 801s at about 1024x720 - soft picture but no scan lines.


3. for every different scan rate and resolution the PJ will "jump" into a memory block to suit that inout - this is actually an excellent idea as one PC may not output the same as another, so different kit will be slightly different, so YES a setup for each input.....


4. Dont worry - the only thing to try and avoid is static images, playing games will not wear your tubes any more than watching tv....

(wear and burn are 2 different things)


5. Try the convergence yourself - that is the easy part......setting up the elctronics, and magnets is really where the money on a pro is best spent....

Dont be frightened to try things.....BUT DONT PUT YOUR FINGERS IN A LIVE PROJECTOR - ALSO be carefull....even when in standby - there are STILL live areas inside the PJ....




I also think you might be confussed about 1080i


that should be 1920 x 1080 resolution - the 800 will not do that, the 801s DATA did 1200x900 the Graphics did 1600x1200 - I think! so the 800 just wont do 1080i



Hope that is some help to you.

 

[kal]

The Barco 800 will do 1080i without any problems. 1080p is definitely not possible.


Kal

 

[redcorvette_85]

Thanks for the help so far Mad and Kal. I still curious if anyone has an opinion on the picture quality of a focus centerstage CS-HD. Also my question on the video game thing was more for static images in the game such as scoring or health meters and such that are constantly on the screen and how long they would take to burn into the tubes. I not worried about doing convergance on my own at all or doing basic stuff inside the projector(had to swap out some boards to get my projector going in the first place) just from what I have read on the boards the pros can dial in a system really well and thats what I was looking for not a full setup of everything, but maybe its not worth it untill I can get a better projector. As for the 1080i thing maybe I am confused I know my projector wont do 1080p by any means, but I thought 1080i was basically the same as 540p, but instead of 540 constant lines they are interlaced. I guess my real question would be if 720p would make the picture too soft for my projector, but I may just be confused on how resolution works.


Thanks again

 

[linecircle]

From what I've noticed, a lot of the statements about projectors handling a resolution is based upon attaining the best picture quality. You most likely can get the pj to display a high resolution, but it wouldn't look at good as a lower one. While bandwidth issues are always bad, sometimes softness is preferred. So you'll see people liking resolutions that don't fully resolve, but to them, it looks better.

 

[kal]

Quote:

Originally Posted by redcorvette_85 As for the 1080i thing maybe I am confused I know my projector wont do 1080p by any means, but I thought 1080i was basically the same as 540p, but instead of 540 constant lines they are interlaced.

Exactly correct!


540p or 1080i at 60Hz is only around 34Khz scanrate. A walk in the park for this projector. It'll have no problems handling and readily resolving 1080 interlaced lines. Yes, the scanlines will be finer and more visible on a better projector but the Barco 800 won't have problems.

Quote:

I guess my real question would be if 720p would make the picture too soft for my projector, but I may just be confused on how resolution works.

If you get the 4x3 ratio screen you talked about then 720p is a perfect resolution to run the BD800 at. It shouldn't have any problems resolving the lines on a 4x3 screen if set up correctly. It may be a bit much for a 16x9 screen however (you use less of the tube phosphor surface so the scanlines are physically closer together). That being said, I ran a BG800 for 5 years on a 16x9 screen at 720p and it looked great. I could *just* make out scanlines in the middle of screen if I looked close enough. 600p might have been better but I enjoyed 720p more so I left it at that.


Kal

 

[kal]

Forgot to answer your question regarding playing video games and "how long is too long":


There's no really "too long" IMHO. Phosphor wear is cumulative, so one hour a day for 5 days is the same as doing 5 hours straight. Keep your contrast reasonable (hard to give a hard number but for a Barco 800 lets say under 70) and you shouldn't have problems playing a game a few hours at a time even if there are static bars. Barco really underdrives their tubes on the 800.... at reasonable contrast levels I think it would take hundreds of hours to get any sort of uneven wear due to static text. I put 4000-5000 hours on my BG800 and the tubes were still as minty the day I sold it as the day I got it and I put a lot of widescreen movies through it and not one sign of uneven wear due to the 2.35:1 aspect ratio.


I'm not a big gamer but I did put about 50-75 hours of Half Life 2 on my projector without any problems.


The other thing is that odds are you'll never play *any* game for more then 100-200 hours total (you'll get bored of it and move on way before that), so I wouldn't worry about it.


But the biggest thing is just to make sure you don't have te contrast cranked at 80+.


Kal

 

[MadMrH]

Quote:

Originally Posted by kal Phosphor wear is cumulative, so one hour a day for 5 days is the same as doing 5 days straight.Kal

One hour a day for 5 days = 5 hours.


five days straight 5x24= 120 hours straight! and you are on drugs


five HOURS straight = One hour a day for 5 days



Oh, dont even look at any of my recent posts, yesterday I was KING of mis spelt, mis types, wrong figures - I blame it on new year.......




BUT I need to check - 1080i on an 800 - ARE YOU SURE?........


the 801s GRAPHICS could only do 1600x1200


so I dont see that a DATA 800 is ever gonna manage 1920x1080........



This could be another one of my classic typos........I am just going to check now.......

 

[MadMrH]

So, The Bacro file I have shows the following........


I have no other way of checking.....


Data 800 1180x900 58Hz/120Hz (H/V)

Data 801 1180 x 900 65/140

Data 801s 1180 x 900 65/155

Data 808 1180x900 69/140

Data 808s 1280x1024 75/200


None of those will do 1080i acording to those specs.....


ALL graphics versions of the above will go to 1600x1200 at various rates.

 

[kal]

Quote:

Originally Posted by MadMrH One hour a day for 5 days = 5 hours. five days straight 5x24= 120 hours straight! and you are on drugs five HOURS straight = One hour a day for 5 days

I meant to say 1 hour/day for 5 days is the same as 5 hours straight. Sorry if it was confusing!

Quote:

BUT I need to check - 1080i on an 800 - ARE YOU SURE?........ the 801s GRAPHICS could only do 1600x1200 so I dont see that a DATA 800 is ever gonna manage 1920x1080........

You're confusing progressive with interlaced. When you say that the 801s graphics can sync to 1600x1200 we're talking progressive. 1080i isn't the same as 1920x1080p. 1080i is the same as 540p. Just about any projector out there other then lowly video grade projectors can handle 540p since it's only 34Khz.


Kal

 

[kal]

Quote:

Originally Posted by MadMrH So, The Bacro file I have shows the following........ I have no other way of checking..... Data 800 1180x900 58Hz/120Hz (H/V) Data 801 1180 x 900 65/140 Data 801s 1180 x 900 65/155 Data 808 1180x900 69/140 Data 808s 1280x1024 75/200 None of those will do 1080i acording to those specs..... ALL graphics versions of the above will go to 1600x1200 at various rates.

Again, you're confusing progressive with interlaced.... the list of numbers is all progressive values.


If you want to compare 1080i to these, you need to use the figure ???? x 540 at 60Hz.


540 is smaller then all of the second numbers listed in the specs (the lowest is 900) so no problems.


I ran my BG800 at 1080i with hidef material for over 5 years... no problems. I've also seen 1080i on any number of lowly 7" ES focused data projectors. No problems. Not as detailed as a better 8" or 9" machine of course, but it still works just fine.


Kal

 

[MadMrH]

Hi,


First of all im happy to learn anything new......


I can only check things with what info is available to me and so here is what you have....


To me I currently still think you can not do 1080i on an 800, though 540p yes can be done.


1080i - 1080 interlaced; one of two formats designated as high-definition television in the ATSC DTV standard, with 1,080 vertical pixels by 1,920 horizontal pixels. The i stands for interlaced, as opposed to progressive scanning, used in the second HDTV standard, 720p. Contrary to myth, 1080i is not superior to 720p; 1080i has more scanning lines but also suffers the disadvantages of interlaced scanning.

taken from http://www.cnet.com/4520-7874_1-5107912-1.html


1080i stands for resolution of 1920x1080 pixels and the magic little 'i' means that the video is being interlaced

taken from http://www.afterdawn.com/glossary/terms/1080i.cfm


1080p stands for resolution of 1920x1080 pixels and the magic little 'p' means that the video is in progressive format

taken from http://www.afterdawn.com/glossary/terms/1080p.cfm


Basically, how the interlacing is done, let's say in PAL format, is that each frame is split into two separate pictures, which both are missing half of the picture information. The split is done by its horizontal lines. The PAL video contains 576 horizontal lines -- let's say that the numbering of these lines begins from the top of the frame being the line number 1. The frame is being split to half-frame A and half-frame B -- the half-frame A would contain lines 1, 3, 5, 7, ... and the half-frame B would contain horizontal lines 2, 4, 6, 8, 10, ...


So, when the video is shown with PAL that has frame frequency (fps) of 25fps, there are 50 "half frames" per second that are being updated. First comes the first full frame's "half A" that fills horizontal lines 1, 3, 5, .. leaving other ones blank (assuming that we start from a "zero state" that output doesn't have anything shown before we start counting this). Then comes first full frame's "half B" that fills the missing lines 2, 4, 6, ... and leaves the existing "half A"'s lines showing as well -- now we have the frame no.1 fully shown on screen. Then comes frame no.2's "half A" that then wipes off the frame no.1's "half A", but leaves the frame no.1's "half B" showing. So, now we have a mixture where lines 1, 3, 5, 7, .. are being filled by frame no.2 and lines 2, 4, 6, .. are being filled by frame no.1.

taken from http://www.afterdawn.com/glossary/terms/interlace.cfm


Also see http://www.google.co.uk/search?hl=en...q=define:1080p

for 1080p definitions and


last one......

http://www.google.co.uk/search?hl=en...%3A1080i&meta=



Now, if I have this wrong then I am happy to change my views...........


BUT 1080i as I understand still needs 1080 vertical lines, yes only half are in use at any one time BUT that is not 540 used then the same 540 used with different info....As I understand it is 1080 lines with alternate lines in use for an i style picture.


1080p uses all 1080 vertical lines in each frame.


PLEASE, if I have this wrong expain to me.......


Im open minded and all the numbers are a mine field but as I understand it I dont think you have this right Kal - I see what you mean but 1080i is not the same resolution as 540p .


you need 1920x1080 resolution for either 1080i or 1080p the way the data is shown differs, resolution is constant.


IF you used 540 lines in the PJ to produce a 1080i image (as I think you mean) thenthe picture would be a bit of a blur I think.


I am happy to be wrong but would like to understand why I am wrong?

 

[kal]

Ok, I see where our confusion might come from now... when you say:

To me I currently still think you can not do 1080i on an 800, though 540p yes can be done.


What do you mean by "do"? If you mean 100% resolve individual scanlines then sure, I agree: The 800 will have problems displaying really discrete scanlines. This is the case where 540p is obviously not the same as 1080i (540 lines vs 1080).


The projector will however sync to 1080i without any problems at all. Since 1080i is only 34Khz. There may be some overlapping of lines, but it will still look 100x times better then say a true 540p resolution source.


Kal

 

[MadMrH]

See if I can get this right...........tell me if you agree with the following and let me try and understand where i go down a different path....


The Barco Data 800 will acept a maximum resolution of 1180x900 refresh rate needs to be within acceptable values (dont know what they are)


In the past when I have gone above max resolution the PJ's have shut down the HV and the tubes........now this could be that the higher resolution AND refresh rate were to high and that if I had reduced the refresh rate then the PJ might have shown the higher resolution..........


What I still dont get is if the max resolution is 1180 x 900 how can it show 1920x1080 at any refresh rate - even low enough to be within the bandwidth.....


OR is the Barco spec meaning something different.


thanks for your help here - I would like to get this right,

 

[kal]

There's no "maximum resolution" that any projector can accept. Projectors have both a maximum scanrate and maximum bandwidth. Let's forget about bandwidth for the moment as it's not that important for this discussion.


So max scanrate is all that matters. If I remember correctly the Barco Data 800 has a max scanrate of around 65Khz. This is the max scanrate that the projector can SYNC to (not the same as the max resolution that the tubes can readily resolve - these are two different things - most [all?] projectors will sync to much higher resolutions then the tubes can actually resolve as you probably know. The 8"/ES focused tubes in the BD800 can't do much more then 700 or 800 lines).


Scanrate is a combination of resolution and refresh rate. For example, 1024x768 at 60Hz works about to about:


768 x 60 x 1.05 = 63Khz (the 1.05 multiplier is a fudge factor to compensate for front & back porches ...)


So [email protected] is close to the limit of what a BD800 can display. You can increase this to 800p or maybe even 850p if you reduce the refresh rate accordingly. All that matters is that you stay below the scanrate limit of the unit.


The trick with 1080i is that because it's interlaced, it's only drawing a complete pass of scanlines with every two passes. In other words, the refresh rate is HALVED. So 1080i is the same as 1080p running at 30Hz (not 60Hz).


So for 1080i we use:


1080 x 60Hz/2 x 1.05 = around 34Khz scanrate.


Kal

 

[MadMrH]

OK,


it looks like the barco info file I have that says "maximum resolution" has then confused me.


what you have said makes perfect sense to me, all the way from the start, just this file showing me limits of resolution obviously added wrong info for me.


its an excel file so I cant upload it here.....


Check the Barco file on Curts site


Barco Max Horiz/Vert Frequency & Resolution Spreadsheet


thats what I was looking at, it shows max resolutions........

 

[Wilds]

Thanks guys, my head is spinning, but my understanding is increasing. Good thread!

 

[kal]

Quote:

Originally Posted by MadMrH Check the Barco file on Curts site Barco Max Horiz/Vert Frequency & Resolution Spreadsheet thats what I was looking at, it shows max resolutions........

Yup! I've seen the file.... Nothing wrong with showing max resolution with a refresh rate (usually 60 since it's fairly standard) as long as they show the max scanrate as well.


Kal

 

[MadMrH]

Thank you for your time KAL..............


Makes sense now I understand that file better.

 

[VideoGrabber]

[NB: Well, that's what I get for starting a response at 7pm, going off to set up some D-VHS recordings, and coming back hours later to finish up. ]


MadMrH has managed to muddy the waters quite a bit:

> ...as I understand it I dont think you have this right Kal so I dont see that a DATA 800 is ever gonna manage 1920x1080... I am happy to be wrong but would like to understand why I am wrong?