thats messed up, i have a normal crt tv and computer monitor i leave both on 24/7 and for many years they have not gone down in quality or had ne problems, i think i might be developing a tumor but no problems on their side, how come a crt projector can't stay on for more than an hour?
I thought about that before, CRT tv last like 7-10 years I hear but their tube(1) and the projectors Tubes(3) are very different in brightness.You cant use your tv as a projector..well not very well at least..lol,I know technicians who can BOOST your tvs brightness substantially but it will decrease the CRTs life,the projector is already very bright so thats why its life goes faster...But CRT prjs are last like 10,000 HRS at full brightness,if you lower you brightness you increase life 🙂
The guy who sold me my barco had a CRT since the 70's and he sez its still perfect, he said a it was a Novabeam...something liek that..lol so CRTs dont die quick if you know what your doing...Hopefully I will know what im doin ...soon..lol
The guy who sold me my barco had a CRT since the 70's and he sez its still perfect, he said a it was a Novabeam...something liek that..lol so CRTs dont die quick if you know what your doing...Hopefully I will know what im doin ...soon..lol
im gettin a fuzzy image with my CRT...I was told that its the BNC cables...Does any one have experience with this? The Cables "Look" fine..but I dont know..
I get vertical scan lines im using SVHS for image.
if it IS the BNC cables can I jsut buy normal BNC cables or do I need "special" cables?
ND
I get vertical scan lines im using SVHS for image.
if it IS the BNC cables can I jsut buy normal BNC cables or do I need "special" cables?
ND
yea I have seen even 80's Crt projectors and the contrast is a thing to behold, granted they arnt really bright But for My basement HT its in the dark anway so Im considering a CRT for there and use the proxima in the family room 😀
I remember someone said that CRTs cant go beyond 100"
there are more pics where that came from too lol
also heres an LCD CRT comparison "like never before"
eyes candy 🙂
ND-
An externally hosted image should be here but it was not working when we last tested it.
there are more pics where that came from too lol
also heres an LCD CRT comparison "like never before"
An externally hosted image should be here but it was not working when we last tested it.
eyes candy 🙂
ND-
Guess I'm going to bring this thread up from the dead for a little bit. Here's the reason why.
I'm going to build an LCD projector. I got this copy lens from surplus shed that's equivalent to the fujinon in everyway. I wanted to test the color rendering it does (since I wasn't sure of the coating or if it was from just a B&W copier). I did an initial test in my thread and it was pretty good. However I didn't test for color. Well, I was going to get a color transparency but then it hit me try it on a TV. I have this crappy 13" goldstar TV (for a guest room) it's bright (not projected) but it's image suffers from achromatic abration. I get red lines on one end of a object and a blue line on another and it's a curved screen. Considering this, it's projected image is not half bad. The brightness isn't bad as long as I sit straight in front of my 6" da-lite reflective bead screen. What I'm going to do while I gather the parts for the LCD is create a better CRT projection. I can get a 70mm lens with an f2.5 rating (175mm FL). That's almost 50% more light gathering ability of the copy lens at f4.5. Now I was thinking of picking up this nice looking 13" SONY WEGA for $179.
Between the 70mm lens and the Sony TV I should get a really good projection. It'll at least give me something to watch while I tinker away at the LCD projector with the CRT rig keeping me motivated.
BTW: Concerning that post above, those pics look like the ones I've seen on a million of those $20 fresnel lens sites and the same guys (yeah right 100" projection with a fresnel) pull the other one. 😀
I'm going to build an LCD projector. I got this copy lens from surplus shed that's equivalent to the fujinon in everyway. I wanted to test the color rendering it does (since I wasn't sure of the coating or if it was from just a B&W copier). I did an initial test in my thread and it was pretty good. However I didn't test for color. Well, I was going to get a color transparency but then it hit me try it on a TV. I have this crappy 13" goldstar TV (for a guest room) it's bright (not projected) but it's image suffers from achromatic abration. I get red lines on one end of a object and a blue line on another and it's a curved screen. Considering this, it's projected image is not half bad. The brightness isn't bad as long as I sit straight in front of my 6" da-lite reflective bead screen. What I'm going to do while I gather the parts for the LCD is create a better CRT projection. I can get a 70mm lens with an f2.5 rating (175mm FL). That's almost 50% more light gathering ability of the copy lens at f4.5. Now I was thinking of picking up this nice looking 13" SONY WEGA for $179.
Between the 70mm lens and the Sony TV I should get a really good projection. It'll at least give me something to watch while I tinker away at the LCD projector with the CRT rig keeping me motivated.
BTW: Concerning that post above, those pics look like the ones I've seen on a million of those $20 fresnel lens sites and the same guys (yeah right 100" projection with a fresnel) pull the other one. 😀
Hmm. I use a 14" tv with a 175mm diameter triplet lens, and get bright enough results at 80inches, excellent at 60. The tv is 15yrs old so the sharpness is pretty bad. I bought a new 13" tv, but took it back. 100$ is not worth it for me. My projection screen is a DaLite 84" lenticular silver screen, 1.8gain. Manual rollup. Got it in a trade for some computer parts, not very great condition, but good enough. Got it cheap.
If I can find a 13" curved screen tv that has svideo input or atleast a comb filter for a decent price, im gonna buy it, build an enclosure, flip the yoke wires (to flip the image on the TV), and have a nice basic single tube crt projector.
BTW. my lens retailed at $1000 about 20-30 years ago.
.....Fresnels suck for an objective lens.....
If I can find a 13" curved screen tv that has svideo input or atleast a comb filter for a decent price, im gonna buy it, build an enclosure, flip the yoke wires (to flip the image on the TV), and have a nice basic single tube crt projector.
BTW. my lens retailed at $1000 about 20-30 years ago.
.....Fresnels suck for an objective lens.....
I'd like to make a correction from my previous post I typed 6" da-lite screen that should be 6' (foot).
Yup, that's the bottom line. 😀
That's a damn big lens almost 7inches. The 63mm copy lens I have now throws a very watchable image especially when viewed directly in front of the da-lite screen. I was actually quite surprised. Other than the issues I've mentioned above about this gold star T.V. is that it can't handle anything other than upright position or else its color goes wacky as if you have a magnet next to it. I've even tried a suggestion of placing the TV in its upside down postion and allowing it to sit for some time then plug it back in and turn it on but nope that didn't work either.
I wouldn't even give this T.V. to a charity even though it's bright that's all it's got going for it.
So my thinking is, get the Wega T.V. with it's apperature grill CRT which is in itself much brighter than a shadowmask grill CRT coupled with the improved Wega design of allowing more electrons to pass through the grill to hit the phosphore which translates to even a brighter image and the larger lens at 70mm with a much better F stop than my copy lens. I should experience some excellent results for CRT projection.
Yup, that's the bottom line. 😀
That's a damn big lens almost 7inches. The 63mm copy lens I have now throws a very watchable image especially when viewed directly in front of the da-lite screen. I was actually quite surprised. Other than the issues I've mentioned above about this gold star T.V. is that it can't handle anything other than upright position or else its color goes wacky as if you have a magnet next to it. I've even tried a suggestion of placing the TV in its upside down postion and allowing it to sit for some time then plug it back in and turn it on but nope that didn't work either.
I wouldn't even give this T.V. to a charity even though it's bright that's all it's got going for it.
So my thinking is, get the Wega T.V. with it's apperature grill CRT which is in itself much brighter than a shadowmask grill CRT coupled with the improved Wega design of allowing more electrons to pass through the grill to hit the phosphore which translates to even a brighter image and the larger lens at 70mm with a much better F stop than my copy lens. I should experience some excellent results for CRT projection.
Now I see what you guys mean about taking pictures of projected images. This is the best pic I could take without too much fuss but it is alot brighter to the naked eye (though nowhere near a well designed LCD projector). Look at the white areas you can see what I mean about the misaligned colors (due to the crappy TV and not the copy lens). This is a pic of the late show on CBS with the star of "Without a Trace" as the guest. The image is upside down because that's how I'm viewing it right now and was taken from about 3ft away from the screen. The only modification to this picture was the image size. Believe me though, the overall image is alot nicer and brighter than the picture portrays. If it wasn't upside down I would watch it alot (even with the crappy gold star TV 😀).
Click on Thumb
Click on Thumb
An externally hosted image should be here but it was not working when we last tested it.
Ok.
This is a project built by Prof, at diyprojectiontv MSN forum.
It uses a Samsung 14" flat screen TV, a 150mm triplet lens, and a homebuilt (also designed and make by Prof) projection screen, entitled the Ultra High Gain Screen Mk. II, with about a 9.0 Gain! The image is either 93 or 100" im not sure.
Some pics are from DVD, some are VHS i think.
Here are the pics
...RESPECT...
This is a project built by Prof, at diyprojectiontv MSN forum.
It uses a Samsung 14" flat screen TV, a 150mm triplet lens, and a homebuilt (also designed and make by Prof) projection screen, entitled the Ultra High Gain Screen Mk. II, with about a 9.0 Gain! The image is either 93 or 100" im not sure.
Some pics are from DVD, some are VHS i think.
Here are the pics
...RESPECT...
My suggestion.
Get a flat screen Wega (i think they are all flat) or any other brand with a flatscreen. Get one thats 13 or 14 inches. Next, find an old opaque projector. One of those bigass ones. I got one for 9.99 (totalling 15$ after taxes and pickup fee), the lens turned out to be a 135mm all glass triplet lens, looking completely identical to the one at diylabs for 119.99.
Next get a nice bright projection screen (you already got one).
Get the wires switched (yokes) in the tv, or use the mirror in the opaque projector, to get the image up the right way.
Build an enclosure (or saw off the top of the opaque projector and use that, focus on the screen at desired size (i suggest about 50-70", depending on screen gain) and enjoy.
BTW. whats the gain on your projection screen, and whats its size.
Get a flat screen Wega (i think they are all flat) or any other brand with a flatscreen. Get one thats 13 or 14 inches. Next, find an old opaque projector. One of those bigass ones. I got one for 9.99 (totalling 15$ after taxes and pickup fee), the lens turned out to be a 135mm all glass triplet lens, looking completely identical to the one at diylabs for 119.99.
Next get a nice bright projection screen (you already got one).
Get the wires switched (yokes) in the tv, or use the mirror in the opaque projector, to get the image up the right way.
Build an enclosure (or saw off the top of the opaque projector and use that, focus on the screen at desired size (i suggest about 50-70", depending on screen gain) and enjoy.
BTW. whats the gain on your projection screen, and whats its size.
Yup, my first post above in this thread has the link to the 13" Sony Wega the specs on this TV are awesome and the price is not bad.
1: Saves me some expense there right now.
2: Hmmm, it's one I bought a long time ago still in pristine condition. Da-Lite Challenger 7 foot diagonal (I just measured it). Not sure of the gain but going by the Da-Lite web site I would say it is most like the Video SpectraTM 1.5
with a gain of 1.5. The angle is about right 35 deg because if I stand at around 45 deg the image gets really dull but anything between that to straight on it's good wth the CRT.
Here's a photo I have in another thread
My Da-lite Challenger
(sorry didn't make thumb pic)
I looked into that after you mentioned it in your previous post. You have to
reverse the horizontal and vertical wires that go to the tube . Looks fairly straight foward. What I was thinking of doing is building a box place the TV inside that on it's back with screen facing up placing the lens right above that and use a surface mirror (just like the OHP uses) this way I only need to reverse one set of wires the horizontal. I will use the Gold Star TV to try this out first. I'm well aware of the dangers Thanks for that link to the CRT pics. Really sweet. I was watching stargate the other day (yeah upside down 😀 ) and when there's a closeup on the faces it really looks great with detail, color and passable brightness much like the detail in that first pic in the link just not as bright.
Will do that. Thanks for the suggestion.
Umm, I hope I haven't hijacked this thread too much since it is about CRT's being no good for projection. But I've come to the conclusion that it's not all together a correct statement if it's done right (without the fresnel scam) I can forsee great results even from my flunky set up. 😀
if you point the tv upwards and use a lens and fs mirror, you will not need to mess with wires. The image will be the right side up.
When you project from just the tv through that lens, you get a vertically FLIPPED image, not rotated upside down. If you flip both yokes, I belive the image will be the right way up, but flipped sideways. Dont mess with the wires until you try the mirror!
Good luck,
Post back when you get more progress,
Its good to have someone here on the CRT side for a change😀 .
BTW, nice screen, I also have a DaLite rollup screen, with 1.8 gain.
When you project from just the tv through that lens, you get a vertically FLIPPED image, not rotated upside down. If you flip both yokes, I belive the image will be the right way up, but flipped sideways. Dont mess with the wires until you try the mirror!
Good luck,
Post back when you get more progress,
Its good to have someone here on the CRT side for a change😀 .
BTW, nice screen, I also have a DaLite rollup screen, with 1.8 gain.
Oh okay I was not thinking that one out right. Yeah, would rather do that than take the chance of messing anything up in the WEGA TV. But I will do that with the Goldstar one just to use it until I get the other TV and larger lens.
Like I said, it was quite a surprise putting that copy lens in front of the TV. What makes the whole idea even better you don't need to worry about fans failing, blown balasts or bulbs, getting the right LCD panel, contrast ratio, moire, scaling and putting it all together and you forgot something and poof you blew some things up. 😀 However, all that is not going to stop me from trying to build an LCD projector if I wait a little longer they may have better small panels by then.
You got it.
Well put.😀
When I did a Moire test on my tv (checker board pattern), i got terrible results, all red, blue, green, spotty, shaky juberish of an image. Thats what you get if your tv doesnt have a Comb filter (S-video has comb filtering, so if you tv has s-video in, no combing should occur).
Heat worries me the most when building an lcd projector.
When I did a Moire test on my tv (checker board pattern), i got terrible results, all red, blue, green, spotty, shaky juberish of an image. Thats what you get if your tv doesnt have a Comb filter (S-video has comb filtering, so if you tv has s-video in, no combing should occur).
Heat worries me the most when building an lcd projector.
Well looks like the Wega is out of the picture. I didn't notice this TV didn't have S-video among other issues. My Ati card for my computer has an Svideo hookup for TV so that is a must.
Here's one review
I've read some really nice things about the Toshiba 14AF4(#) (14") series. It uses the invar shadow mask and is true flat so it won't be as bright as the Wega I don't know why sony didn't include an Svideo on that 13" since they did include this in their larger screens above 13" (no they don't make a 14" another dumb move). Anyway, The specs look nice for the toshiba and it's got a 16:9 mode which the 13" Wega doesn't have either. I'll have to check this out next time I'm near a store that carries it. More than likely I'll go with that one.
Here's one review
I've read some really nice things about the Toshiba 14AF4(#) (14") series. It uses the invar shadow mask and is true flat so it won't be as bright as the Wega I don't know why sony didn't include an Svideo on that 13" since they did include this in their larger screens above 13" (no they don't make a 14" another dumb move). Anyway, The specs look nice for the toshiba and it's got a 16:9 mode which the 13" Wega doesn't have either. I'll have to check this out next time I'm near a store that carries it. More than likely I'll go with that one.
Hmm there should be an svideo on that Sony one....wierd... If you get an ATI component adapter, you can plug your computer into your tv with component jacks at 480i format.
What I dont get is why is there a composite in, in the back, but no audio in? I think you maybe missing some connections from that list. What is the model number of that TV? Im gonna download the manual for it and see.
The best TV to use for this project seems to be a 14" flatscreen advent tv. There is a special combination of buttons that you press to enter service mode that will allow you to have much more brightness and contrast, and to have anamorphic (16:9 squeeze just like on the toshibe) mode.
The toshiba should work well too.
Once again - good luck.
What I dont get is why is there a composite in, in the back, but no audio in? I think you maybe missing some connections from that list. What is the model number of that TV? Im gonna download the manual for it and see.
The best TV to use for this project seems to be a 14" flatscreen advent tv. There is a special combination of buttons that you press to enter service mode that will allow you to have much more brightness and contrast, and to have anamorphic (16:9 squeeze just like on the toshibe) mode.
The toshiba should work well too.
Once again - good luck.
Sorry for not reading the whole thing, just wanted to toss in my 2 cents.
I come from the "TV business", meaning repairing and delivering
and I´ve never been a friend of CRT-projectors.
Neither of the technique nor the picture.
99% are only good for one person to watch and some even can´t satisfy that. I remember a Thomson model (strange enough) that was really good but then again the price/quality ratio wasn´t real fair.
Convergence problems with these CRT´s is THE standard fault, 2nd being defective CRT´s which cost a little fortune.
Another big problem is that dust, nicotine and whatever easily get into the TV and will worsen the picture quite fast.
That said I´ve also seen plasma TV´s having no good picture (not natural for example) so be careful what you buy and check over and over again.
I wish I could still buy some of the older Sony 50Hz TV´s having a picture better than most modern 100Hz TV´s.
That was great quality!
Along with some (actually most) Metz TV´s and also most Loewe TV´s.
Too much mass production in that area IMHO.
And even if you buy a so called high-end TV you´ll get new techniques with it that are not testified and will eventually fail.
(simplified: in that area the customer is the test-person)
Still looking forward to see some good plasma displays with reliable technique.
I come from the "TV business", meaning repairing and delivering
and I´ve never been a friend of CRT-projectors.
Neither of the technique nor the picture.
99% are only good for one person to watch and some even can´t satisfy that. I remember a Thomson model (strange enough) that was really good but then again the price/quality ratio wasn´t real fair.
Convergence problems with these CRT´s is THE standard fault, 2nd being defective CRT´s which cost a little fortune.
Another big problem is that dust, nicotine and whatever easily get into the TV and will worsen the picture quite fast.
That said I´ve also seen plasma TV´s having no good picture (not natural for example) so be careful what you buy and check over and over again.
I wish I could still buy some of the older Sony 50Hz TV´s having a picture better than most modern 100Hz TV´s.
That was great quality!
Along with some (actually most) Metz TV´s and also most Loewe TV´s.
Too much mass production in that area IMHO.
And even if you buy a so called high-end TV you´ll get new techniques with it that are not testified and will eventually fail.
(simplified: in that area the customer is the test-person)
Still looking forward to see some good plasma displays with reliable technique.
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