mathias said:
ok let me get this straight if my room is 12 feet long the biggest image i can project is 6 feet wide? that sounds more like a fault than a rule to me. i can easily project 10 feet wide and sit 5 feet away without seing anyscreen door whatsoever from this diy pj.
if i followed that rule i would have to sit 20 feet away i think thats a cover up for for the low quality standards of xga and lower resolution lcd projectors
think about it, i go into a theater and sit 12 feet from a 25 foot wide screen so those rules dont aply to theaters?
sure i agree 800X600 is plenty for dvd playback dvd's are only 720X480 but who in the right mind would buy a 800X600 lcd projector when you can build a high definetion projector for about the same money with $40.00 bulbs and the picture quality is no contest.because its smaller? or brighter? who in the right mind watches their projector in the daytime with the windows open.
i estamate you can build a 1600X1024 true 16.7 millon color lcd projector "once diylabs comes thru with the fresnel deal " for as little as $700 with good scouring on ebay for the sgi monitor,sure its not gonna be 10,000,000 lumens but in a well controled room look out!!! you will be passing pillows out to keep ppl's jaws from hitting the floor
i will agree again with you if i sit 10-12 feet away from a xga diyprojector at 100" diagonal i dont see anyscreendoor but then the imersive feeling is lost i may as well buy a tv!!
im not trying to start a fight with you im just bringing forward my views on what i have learned in the past year or so building these projectors,i do not claim to know everything im learning every day. i will not come in here and lie to ppl if i do not know, i do not speak!!
with that being said i respect anyones opinion on their views and goals twords whats good enough for them. personaly my goal is 1080p for under $1000 now, and its definetly possible!!!
oh yeah 1 more pic i just love posting pictures i know they mean nothing but its fun either way,its hard to drive a drag car being 20 feet away from the stering wheel lol j/k happy DIY people
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Actually the rule is that you sit one and a half times the screen distance away from the screen.
i.e. if you're 15 feet away, the screen should be ten feet. But it's just that, a rule of thumb. Go with what screen size u like. Many die hard videophiles think 100" screens are sacreligous. Many people like 100" plus screens. So play with it and find the size you like.
As far as 800x600 displaying full dvd resolution, that's not entirely true. fullscreen material maybe, but I'm pretty sure 800x600 falls short of 720x480 DVD res when viewing some letterboxed movies. Or it's very close at least. someone do the math and don't quote me on that lol.
Besides, part of the point of this is that our computers scale the video for us. The more resolution, the more the software scales it, and the better it can look. Granted, DVD only has so much resolution, and line doubling and tripling only make it look so much better, but they do, and every bit helps.
I'd like some 1080p too, but is there really such a thing as a under 17" lcd with 1920x1080 resolution?
Besides, there is hardly any 1080p material available anywhere. As far as I know, only with WMHD or with some really high end scalers will you get it.
I think 720p is more reasonable to shoot for. Just my opinion...
i.e. if you're 15 feet away, the screen should be ten feet. But it's just that, a rule of thumb. Go with what screen size u like. Many die hard videophiles think 100" screens are sacreligous. Many people like 100" plus screens. So play with it and find the size you like.
As far as 800x600 displaying full dvd resolution, that's not entirely true. fullscreen material maybe, but I'm pretty sure 800x600 falls short of 720x480 DVD res when viewing some letterboxed movies. Or it's very close at least. someone do the math and don't quote me on that lol.
Besides, part of the point of this is that our computers scale the video for us. The more resolution, the more the software scales it, and the better it can look. Granted, DVD only has so much resolution, and line doubling and tripling only make it look so much better, but they do, and every bit helps.
I'd like some 1080p too, but is there really such a thing as a under 17" lcd with 1920x1080 resolution?
Besides, there is hardly any 1080p material available anywhere. As far as I know, only with WMHD or with some really high end scalers will you get it.
I think 720p is more reasonable to shoot for. Just my opinion...
Of course that's not to say 1080p doesn't look better than 720p even without the full res. It does. 1080p vs 720p with my monitor at 1280x1024@75hz, 1080p looks obviously more crisp. I guess I was just saying more HD sources will be in 720p than 1080p. But if wmhd catches on, that could change. Hopefully it does.
hi mathias, i think standards must be way different in sweden. two times
the screen width? that would mean in a small room 12' wide with a
a chair placed away from the wall and say 8' form the screen, it would
only allow a 4' wide screen. that's down right tiny. "most people" here want
to recreate the movie experience where the screen fill up most of your
vision. more like 1 to 1, or 1 to 1.5 width.
as far a 800x600 being good enough for dvd's. i use this resolution daily
on a commercial projector in a 20' living room, it certainly isn't very good.
lot of screen door, also no one mentions all the other video artifacts that
show up more at lower resolutions, lines-diagonals video crawl etc. on a
1024x768 or 1600x1200 these things are much less noticable.
now if one also wants to use a projector for data-computer use, web use,
showing photoshop pics, running applications, games, then 800x600 i
find almost worthless.
i quess it just depends on how one uses the equipment, if i only watched
movies on a 4' screen at 8' then i agree completely, i would not see the
screen door or most artifacts etc. i could be wrong about "most people"
here, but everyone i know runs much larger screens and sits much closer.
all the best tony.
the screen width? that would mean in a small room 12' wide with a
a chair placed away from the wall and say 8' form the screen, it would
only allow a 4' wide screen. that's down right tiny. "most people" here want
to recreate the movie experience where the screen fill up most of your
vision. more like 1 to 1, or 1 to 1.5 width.
as far a 800x600 being good enough for dvd's. i use this resolution daily
on a commercial projector in a 20' living room, it certainly isn't very good.
lot of screen door, also no one mentions all the other video artifacts that
show up more at lower resolutions, lines-diagonals video crawl etc. on a
1024x768 or 1600x1200 these things are much less noticable.
now if one also wants to use a projector for data-computer use, web use,
showing photoshop pics, running applications, games, then 800x600 i
find almost worthless.
i quess it just depends on how one uses the equipment, if i only watched
movies on a 4' screen at 8' then i agree completely, i would not see the
screen door or most artifacts etc. i could be wrong about "most people"
here, but everyone i know runs much larger screens and sits much closer.
all the best tony.
faithblinded said:
faithblinded there is such a lcd its a 15.4" widescreen 1920X1200
but the problem is its a laptop lcd i have ben getting newsletters from quite a few display controller companys that are producing wuxga controllers hopefully and i mean "hopefully" i will be able to work out a deal for a sample soon
i agree 720p is quite acceptable no doubt about it but i have reached that goal and now its time to step it up a notch
The THX recommendation is 1.5 * the picture width or 36 degrees viewing angle at most, I am sorry if I wrote something else. Higher resolution is always better and nobody have sad anything else. Yes you can sit closer to the screen with higher resolution, but you have to turn your head 180 degrees everytime something happen on the other end of the screen, like a tennis match, personal I think this is damn tiring.
Most people don´t want a big 15-17" diy-projector design in their livingroom, and right now that is the only way to go if you want higher resolution than 800*600. The screendoor effect you get is very easy to minimize just put your projector a little out of focus and the effect is almost gone.
And one thing nobody is talking about is the fresnell rings, I can say that I did try everything to make them disappear, but they was always there and with a resolution of 1024*768, the rings was alot bigger problem than the screendoor effect.
Most people don´t want a big 15-17" diy-projector design in their livingroom, and right now that is the only way to go if you want higher resolution than 800*600. The screendoor effect you get is very easy to minimize just put your projector a little out of focus and the effect is almost gone.
And one thing nobody is talking about is the fresnell rings, I can say that I did try everything to make them disappear, but they was always there and with a resolution of 1024*768, the rings was alot bigger problem than the screendoor effect.
Anyone who says anything over 1000 ansi lumens is too bright is nuts! You put a 500 ansi lumen unit next to one that pumps out 1500 to 2000 plus and tell me with a straight face that you'd rather buy the 500... LOL! Hotspots and overly bright whites are fixed with menu controls friends.
And I'm with Cruser... anything below XGA res is a waste of time. I dont care if you build a projector that fits in your pocket!
JCB
www.diybuildergroup.com
And I'm with Cruser... anything below XGA res is a waste of time. I dont care if you build a projector that fits in your pocket!
JCB
www.diybuildergroup.com
Wow it just goes to show your knewlege level, ive never seen a on- screen menu for controlling a hot spot before, wow, must realy be a work of art considering its impossible, and all projectors have them weather its diy, pro or even if its hand crafted by the grand wizzard of china.
Nice attitude in the real diy way, for some one who runs a diy site!
About the screendooreffect, you have to compare the same resolution pj, to get a fair result. DIY-pj:s use one lcd panel with red,green,blue next to each others which give one pixel, between every red,green,blue pixelpoint there is a screendoor. On a commercial 3 panel projector the red,green,blue pixels lie on eath other, so in other words the screendoor effect would be 3 times less on a commercialprojector.
I can imagine me, why you see less screendoor on a diy-projector has to do with other things than the resolution. The MH-lamp in a diy-projector has a big arc that is far from a pointsource, the fresnellens is not a perfect opticallens, the objectlens is not the best, the reflector maybe isn´t perfect. All this things can affect how much of the screendoor you can see.
ANSI is a shorting of "American National Standards Institude" and they have all the rules how to measure the light output from a projector and it´s not a easy thing to do, if the manufactures follow these rules or not is an other thing.
Even if the ansi-lumen is very complicated to measure I can tell you that you will not get 500 Ansi lumen with a 150-250W MH lamp on a single panel DIY-projector, maybe with a 400W, I don´t know.
I can imagine me, why you see less screendoor on a diy-projector has to do with other things than the resolution. The MH-lamp in a diy-projector has a big arc that is far from a pointsource, the fresnellens is not a perfect opticallens, the objectlens is not the best, the reflector maybe isn´t perfect. All this things can affect how much of the screendoor you can see.
Well, it depends on how big your screensize is. For a 100" picture size most experts recommend 500-700 ansi lumen, accordingly is 1000 ansi lumen to bright for 100". But if now want a picture size of 150" 1000 ansi lumen maybe is more right.
ANSI is a shorting of "American National Standards Institude" and they have all the rules how to measure the light output from a projector and it´s not a easy thing to do, if the manufactures follow these rules or not is an other thing.
Even if the ansi-lumen is very complicated to measure I can tell you that you will not get 500 Ansi lumen with a 150-250W MH lamp on a single panel DIY-projector, maybe with a 400W, I don´t know.
Who do you mean lie ? Cruser, I must say I don´t understand why you have written some things in this thread that you did, you are far away from the head subject and it´s almost thread-jacking and after that you starting posting completely uninteresting picture that has nothing to do with the subject. I know that the Moderators in this forum allow pretty much, but next time, start a new thread with right subject and post your information there.
Spare me Mathias.
This thread has been jacked since the 3rd or 4th post LOL.
Even your most recent post isnt doing much to answer the subject, which only required one post to be answered.
That being said, this thread has turned into one of the best debates on the site, despite all the mud slinging.
Your statement that a 3 lcd projector has "3 times less" screen door seems like nonsense to me. You even stated my reasoning in your explanation. "On a commercial 3 panel projector the red,green,blue pixels lie on eath other", which in turn means the spaces in between also lie on each other, and are not lessened by the three panels unless they are out of alignment and overlapping one another to cover the screen door. Maybe I'm wrong, but what you said makes absolutely no sense to me. Explain it in a way I can understand.
Furthermore, maintaining the same resolution for screen door comparison is not enough. I think the size of the panel should remain the same for a realistic screen door comparison. I remember hashing this out in a previous thread, and it became clear to me after consideration that a 15" panel @ 800x600 will have more screen door than a 17" panel @ 800x600 with the same screen size. I'm sure dot pitch can effect this too, as not all panels of the same size have pixels the same distance apart. Cruser can give the info, but I believe that SGI panel he uses has an insanely small dot pitch compared to ther lcd's.
Also to the best of my knowledge cruser is using a 400w bulb. IMHO 150 or 250 just wouldnt be enough for a 17" 16:9 panel.
The direction of the thread changed and everyone involved followed along. The pics Cruser posted were well within the scope of the direction the discussion took, which, despite your preaching about thread jacking, you seem to also be ranting on the same off topic subject. So save the high and mighty tone.
Arguing lumens is silly. I doubt any of us have a way to measure them. We aren't working in controlled environments with a system of standards here. It's DIY. We all have different expectations from our DIY PJ's, and the number of opinions on any given subject are without end. But in the end they are just that, opinions. You can tout your "findings" to me all day, but in the end, if you arent a scientist working in a controlled environment, your "findings" mean dick to me. If you think it's bright enough, colorful enough,and crisp enough, great. But don't jack Jo Blo for wanting more, and not being satisfied with what satisfies you.
Of course, that's just my opinion...
This thread has been jacked since the 3rd or 4th post LOL.
Even your most recent post isnt doing much to answer the subject, which only required one post to be answered.
That being said, this thread has turned into one of the best debates on the site, despite all the mud slinging.
Your statement that a 3 lcd projector has "3 times less" screen door seems like nonsense to me. You even stated my reasoning in your explanation. "On a commercial 3 panel projector the red,green,blue pixels lie on eath other", which in turn means the spaces in between also lie on each other, and are not lessened by the three panels unless they are out of alignment and overlapping one another to cover the screen door. Maybe I'm wrong, but what you said makes absolutely no sense to me. Explain it in a way I can understand.
Furthermore, maintaining the same resolution for screen door comparison is not enough. I think the size of the panel should remain the same for a realistic screen door comparison. I remember hashing this out in a previous thread, and it became clear to me after consideration that a 15" panel @ 800x600 will have more screen door than a 17" panel @ 800x600 with the same screen size. I'm sure dot pitch can effect this too, as not all panels of the same size have pixels the same distance apart. Cruser can give the info, but I believe that SGI panel he uses has an insanely small dot pitch compared to ther lcd's.
Also to the best of my knowledge cruser is using a 400w bulb. IMHO 150 or 250 just wouldnt be enough for a 17" 16:9 panel.
The direction of the thread changed and everyone involved followed along. The pics Cruser posted were well within the scope of the direction the discussion took, which, despite your preaching about thread jacking, you seem to also be ranting on the same off topic subject. So save the high and mighty tone.
Arguing lumens is silly. I doubt any of us have a way to measure them. We aren't working in controlled environments with a system of standards here. It's DIY. We all have different expectations from our DIY PJ's, and the number of opinions on any given subject are without end. But in the end they are just that, opinions. You can tout your "findings" to me all day, but in the end, if you arent a scientist working in a controlled environment, your "findings" mean dick to me. If you think it's bright enough, colorful enough,and crisp enough, great. But don't jack Jo Blo for wanting more, and not being satisfied with what satisfies you.
Of course, that's just my opinion...
mathis im sorry if i ofended you my intention in saying i dont come in here and lie was not directed twords anyone ,it simply means to anyone that reads this thread that im not gonna make up storys to make myself look good or any of the projects i do thats all
i think my gramer is bad...real bad it is very hard for me to express myself in writing somrtimes things i say come accros harsh when thats not the way i meant to state myself
and i have to agree with faithblinded this thread was jacked way before i got here ..i know i helped it quite a bit since then but whatever, thats nolonger the point .
there have ben some very interesting debates here in this thread in either lumen output and resolution wich is good for ppl to express their views on bolth subjects . everyone has their right to express their opinion and in doing so helps the DIY comunity i dont hold grudges,and i dont think anyone should we all learn from discussinos like this weather its off topic or not
i apologised to johnjohn2 for jacking his thread and he replyed he enjoyed the disscusion we were havin soaking in the information being brought forward from many amazing ppl on this amazing forum yourself included
I dont think anyone is wrong or right its all opinions so once again im gonna step up and say IM SORRY IF I OFENDED YOU!!!
i think my gramer is bad...real bad it is very hard for me to express myself in writing somrtimes things i say come accros harsh when thats not the way i meant to state myself
and i have to agree with faithblinded this thread was jacked way before i got here ..i know i helped it quite a bit since then but whatever, thats nolonger the point .
there have ben some very interesting debates here in this thread in either lumen output and resolution wich is good for ppl to express their views on bolth subjects . everyone has their right to express their opinion and in doing so helps the DIY comunity i dont hold grudges,and i dont think anyone should we all learn from discussinos like this weather its off topic or not
i apologised to johnjohn2 for jacking his thread and he replyed he enjoyed the disscusion we were havin soaking in the information being brought forward from many amazing ppl on this amazing forum yourself included
I dont think anyone is wrong or right its all opinions so once again im gonna step up and say IM SORRY IF I OFENDED YOU!!!
Ah but wait there is an statement i have to aderess this what was posted by mathis -->Even if the ansi-lumen is very complicated to measure I can tell you that you will not get 500 Ansi lumen with a 150-250W MH lamp on a single panel DIY-projector, maybe with a 400W, I don´t know.
first what is the minimum lumens required to display a well saturated image in daylight? I will wait for your reply, im not starting a fight i just want to clarify things for the comunity thats all
first what is the minimum lumens required to display a well saturated image in daylight? I will wait for your reply, im not starting a fight i just want to clarify things for the comunity thats all
As it turns out, there is a limit today to how close two LCD pixels can be put from each other. The retail pjs use very small LCDs, and if you'll do a calculation, you'll see that the "fill factor" (net pixels on the LCD, without all the margins between them) of a typical 1024x768 LCD retail pj is about 60% (i.e. 40% of the LCD panel is nothing but gaps) . Going to 1280x720 will improve the fill factor (I would say closer to 80%), which will make a noticeable improvement, screen door wise.
Anyhow, because 15" LCD panels are so big (in comparison to the small LCD panels they use in retail pjs), the pixels are big too, so the space taken by the margins between the pixels, in comparison to the pixel's size, is very small (remember, it's the ratio that counts, not absolute sizes). A typical fill factor for a 15" LCD is over 90%. This is why screen door is not an issue with this project (at the same distances it is very much an issue with a retail pj of the same resolution).
Anyhow, because 15" LCD panels are so big (in comparison to the small LCD panels they use in retail pjs), the pixels are big too, so the space taken by the margins between the pixels, in comparison to the pixel's size, is very small (remember, it's the ratio that counts, not absolute sizes). A typical fill factor for a 15" LCD is over 90%. This is why screen door is not an issue with this project (at the same distances it is very much an issue with a retail pj of the same resolution).
First of all I want to say that the head-subject of this thread is now completly gone, and it seems that nobody is intrested in the head-subject anymore. This thread start more look like "DIY Video Projector Part II" And I don´t know what the subject is anymore, if this is wrong or not is upto the Moderators. But one thing I can say, it´s hard to search for information in a forum if the head-subject point to a thread which was a other subject inside the thread.
One thing I don´t understand is that I can clearly see the screendoor on my 15" tft when it´s on my desk, but when I used the same monitor in my diy-projector and a screensize of 100", I could not see anyscreen door even if I stood 2" from the screen, but could see the pixels clearly ??
Why the experts say 500-700 ansi lumen on a 100" screen, is because the movie experience looks more like in the real life then. If there is a scene in a movie when they show a sunny day scene, it should look like a sunny day, not a cloudy day. Yea sure you can have a nice movie experience with 150-200 ansi lumen, but you don´t get that feeling you get on a cinema.
Why I say you don´t get 500 ansi lumen with your single panel diy-projector with a 150-250W MH, is because I have compared my diy-projector with my commercialprojector (800 Ansi) and there is a big difference in brightness and I just got confirmed that the light level is a logarithmic scal. That means a 1000 ansi lumen projector only looks 25% brighter than a 500 ansi lumen projector. This also seems to agree with the list of single panels projectors from "projectorcentral.com" I showed.
I wrote "would" which mean "I´m not sure", and a fill factor of 60% on a commercialprojector seems right to me, thats also what a have read, a DLP has more. Anyway the screendoor effect is not a so very big problem as many think, as I wrote before, you can very easy minimize the screendoor effect just put your projector a little out of focus and the effect is almost gone. But the biggest difference between Single-panel and 3-panelprojectors except the brightness and color, is that the 3-panelprojectors looks more sharper because they don´t have any sub-pixels.
One thing I don´t understand is that I can clearly see the screendoor on my 15" tft when it´s on my desk, but when I used the same monitor in my diy-projector and a screensize of 100", I could not see anyscreen door even if I stood 2" from the screen, but could see the pixels clearly ??
Yea I figured out that someone would ask about that. To project a computer picture on a screen 12 o´clock AM with the daylight through the windows, is not hard at all, even with my old 200W halogen setup, you could see a clearly 60" picture and you can self calulate how many ansi-lumen that projector could have. A well saturated image in daylight, I don´t think you can get that, because you can not shine black, the picture can not be black in daylight.
Why the experts say 500-700 ansi lumen on a 100" screen, is because the movie experience looks more like in the real life then. If there is a scene in a movie when they show a sunny day scene, it should look like a sunny day, not a cloudy day. Yea sure you can have a nice movie experience with 150-200 ansi lumen, but you don´t get that feeling you get on a cinema.
Why I say you don´t get 500 ansi lumen with your single panel diy-projector with a 150-250W MH, is because I have compared my diy-projector with my commercialprojector (800 Ansi) and there is a big difference in brightness and I just got confirmed that the light level is a logarithmic scal. That means a 1000 ansi lumen projector only looks 25% brighter than a 500 ansi lumen projector. This also seems to agree with the list of single panels projectors from "projectorcentral.com" I showed.
One thing no one has mentioned in here is the difference in lumens when watching a movie compared to text, from memory the X1 was suposed to be 1k ansi lumen, in movies its as low as 500lm, so lets not get mixed up in here regarding lumens of their projector as the lumen count will vary, not only from the source signal strength, but also the material you are projecting.
Easy rule to follow, the higher the contrast, the darker the image
will be.
Retail projectors are actually rated with a 80inch screen, thats being CRT, DLP, LCD, anything, thats the size they are rated on, i posted the info with a link up a while ago regarding that.
I could say my projector with the 150w bulb is 1000lm, but at 40inches screen size, no one has realy specified screen sizes in here for the rough estimated lumen count. Run a 1k lm ansi pro projector at 300inches and you will be lucky to have 300lm ansi.
As for the unability to project black, you are very correct, but we can project dark brown.
Trev
Easy rule to follow, the higher the contrast, the darker the image
will be.
Retail projectors are actually rated with a 80inch screen, thats being CRT, DLP, LCD, anything, thats the size they are rated on, i posted the info with a link up a while ago regarding that.
I could say my projector with the 150w bulb is 1000lm, but at 40inches screen size, no one has realy specified screen sizes in here for the rough estimated lumen count. Run a 1k lm ansi pro projector at 300inches and you will be lucky to have 300lm ansi.
As for the unability to project black, you are very correct, but we can project dark brown.
Trev
Lumen is a measurement of the total light output, it should be the same for any screen size. You of course need more lumens with a larger screen to get the same brightness.
The source material shouldn't matter either, the light output is measured when projecting pure white isn't it?
If a projector has a lower rating for movies, isn't that because it has a special movie mode with a lower light output but better color reproduction (or something like that) ?
The source material shouldn't matter either, the light output is measured when projecting pure white isn't it?
If a projector has a lower rating for movies, isn't that because it has a special movie mode with a lower light output but better color reproduction (or something like that) ?
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