Here's a link to some in site on lumens.
http://www.boxlight.com/presenter_resources/articles_page.asp?ARTICLE=ARTICLE1&X=12
http://www.westsidesystems.com/rays.html
Vince
http://www.boxlight.com/presenter_resources/articles_page.asp?ARTICLE=ARTICLE1&X=12
http://www.westsidesystems.com/rays.html
Vince
gmshroll,
You are definitely right about the NUMBER of pixels. I was too tired last night to be making any semi-technical decisions anyway--thanks for correcting me! I checked out the LCDs on the mars-cam.com website, and they do seem nice...a little pricey, though. I have a Marshall MXL-603s condensor mic that I use for recording vocals, guitar, bass, and for live performances, and I have found them to be an incredible value.
Vince,
Thanks for the lumen links...that helps to bring some of these seemingly arbitrary numbers into perspective. I e-mailed AND about the 1.8" concerning the removability of the backplate, and they replied by saying that the 1.8" has been discontinued. They do still produce the 2.5":
AND-TFT-EM25 pdf file
The specs seem nearly identical to the 1.8" except for, of course, the size and price. I think the contrast ratio is a little lower for the 2.5"...more space between the pixels maybe?
It is sold through Allied Electronics, or it is at least listed in their catalog with a price of $131.67 USD.
Allied Electronics LCD page, pdf
My goal right now if to produce a picture of at least 50" with quality equal to or greater than my current 27" CRT TV (piece of junk). I would also like to do this for less than $150, but that might be unrealistic. It's tough living on a student budget!
Thanks for everybody's help.
-f4
You are definitely right about the NUMBER of pixels. I was too tired last night to be making any semi-technical decisions anyway--thanks for correcting me! I checked out the LCDs on the mars-cam.com website, and they do seem nice...a little pricey, though. I have a Marshall MXL-603s condensor mic that I use for recording vocals, guitar, bass, and for live performances, and I have found them to be an incredible value.
Vince,
Thanks for the lumen links...that helps to bring some of these seemingly arbitrary numbers into perspective. I e-mailed AND about the 1.8" concerning the removability of the backplate, and they replied by saying that the 1.8" has been discontinued. They do still produce the 2.5":
AND-TFT-EM25 pdf file
The specs seem nearly identical to the 1.8" except for, of course, the size and price. I think the contrast ratio is a little lower for the 2.5"...more space between the pixels maybe?
It is sold through Allied Electronics, or it is at least listed in their catalog with a price of $131.67 USD.
Allied Electronics LCD page, pdf
My goal right now if to produce a picture of at least 50" with quality equal to or greater than my current 27" CRT TV (piece of junk). I would also like to do this for less than $150, but that might be unrealistic. It's tough living on a student budget!
Thanks for everybody's help.
-f4
The contrast corresponds to the pixels ability to turn off and on.
When full off- you get black. And full on- you get white, but you can not have full off, so you never really get true black. That's why you get poor black in LCDs.
Here's a test, or at least a hypothesis...try shining a strong light through a LCD when it's turned off. That's about as black as you will get when on, maybe even lighter. An argument for not having too strong a light source, if your LCD can't handle the light.
With DLPs you can have full off, or close to it. Depends on the angle of the mirrors.
I saw a DLP in a Bang and Olifsen shop in my mall. They were palying 3000 Miles to Graceland. It was on the part where they are getting away through the Casino. I swear, it was better then being in the theater. I haven't ever seen such colors.
The new Star Wars movie coming out in March will be the first all digital movie, e.i., Shot, edited, transfered and played digitally...through a DLP projector.
What will happen to Cinematographers?
Vince
PS, I was going to bed the other night and I was about to turn the light on my night stand off. I never considered it, but the light bulb in my lamp is a 7 watt flourecent. It barely gets hot.
So I jumped out of bed and grabbed a plano-convex I have and placed it over the lamp. The light intensity was tripled. The bulb cost $7 to $10 at Ikea, has a long life and it very white too.
Something else to think about.
V.
When full off- you get black. And full on- you get white, but you can not have full off, so you never really get true black. That's why you get poor black in LCDs.
Here's a test, or at least a hypothesis...try shining a strong light through a LCD when it's turned off. That's about as black as you will get when on, maybe even lighter. An argument for not having too strong a light source, if your LCD can't handle the light.
With DLPs you can have full off, or close to it. Depends on the angle of the mirrors.
I saw a DLP in a Bang and Olifsen shop in my mall. They were palying 3000 Miles to Graceland. It was on the part where they are getting away through the Casino. I swear, it was better then being in the theater. I haven't ever seen such colors.
The new Star Wars movie coming out in March will be the first all digital movie, e.i., Shot, edited, transfered and played digitally...through a DLP projector.
What will happen to Cinematographers?
Vince
PS, I was going to bed the other night and I was about to turn the light on my night stand off. I never considered it, but the light bulb in my lamp is a 7 watt flourecent. It barely gets hot.
So I jumped out of bed and grabbed a plano-convex I have and placed it over the lamp. The light intensity was tripled. The bulb cost $7 to $10 at Ikea, has a long life and it very white too.
Something else to think about.
V.
With some quick and dirty math, I came up with these numbers:
Example 1:
For a 2.5" LCD with a .106mm X .161mm pixel pitch (480X234 reso.) projected to 75", the projected pixel size would be 3.18mm X 4.83mm.
Example 2:
For a 1.8" LCD with a .076mm X .116mm pixel pitch (480X234 reso.) projected to 75", the projected pixel size would be 3.18mm X 4.83mm. Note that the projected pixel size is the same as the above example because the decrease in pixel size is proportional to the decrease in LCD size. To get to 75", the 1.8" LCD must be magnified more than the 2.5", negating any advantage from the smaller pixel size. This illustrates gmshrolls point from several posts back.
Example 3:
For a 8.4" LCD with a .213mm X .213mm pixel pitch (800X600 reso.) projected to 75", the projected pixel size would be 1.90mm X 1.90mm. BIG improvement.
To make these calculations, I used the formula:
Desired image diagonal size(in)
---------------------------------------- X pixel pitch (mm) = projected
LCD diagonal size (in) pixel size
I roughly drew these calculated pixel sizes to compare the different examples, and the difference between the higher and lower resolution screens was dramatic. This might not matter much to you depending on your goal.
DISCLAIMER: These calculations were made by a math idiot. They are theoretical estimates of what MIGHT be produced. That is, if the math is correct! Use at your own risk!
Example 1:
For a 2.5" LCD with a .106mm X .161mm pixel pitch (480X234 reso.) projected to 75", the projected pixel size would be 3.18mm X 4.83mm.
Example 2:
For a 1.8" LCD with a .076mm X .116mm pixel pitch (480X234 reso.) projected to 75", the projected pixel size would be 3.18mm X 4.83mm. Note that the projected pixel size is the same as the above example because the decrease in pixel size is proportional to the decrease in LCD size. To get to 75", the 1.8" LCD must be magnified more than the 2.5", negating any advantage from the smaller pixel size. This illustrates gmshrolls point from several posts back.
Example 3:
For a 8.4" LCD with a .213mm X .213mm pixel pitch (800X600 reso.) projected to 75", the projected pixel size would be 1.90mm X 1.90mm. BIG improvement.
To make these calculations, I used the formula:
Desired image diagonal size(in)
---------------------------------------- X pixel pitch (mm) = projected
LCD diagonal size (in) pixel size
I roughly drew these calculated pixel sizes to compare the different examples, and the difference between the higher and lower resolution screens was dramatic. This might not matter much to you depending on your goal.
DISCLAIMER: These calculations were made by a math idiot. They are theoretical estimates of what MIGHT be produced. That is, if the math is correct! Use at your own risk!
Liking the maths...
Yeah, this ties in with what I imagined would be the case... My need for a projector is just for video. I went for the 2.5" panel for a number of reasons:
* It wouldn't suffer any degradation of quality using a condenser lens prior to the projection lens. (especially if it was a fresnel).
* The OHP style projection panels that people have had success with seem very nice but I wanted to avoid using one for both space constraints and contrast problems (as on the older ones - not checked new ones)
* I don't know anyone else who's tried it with this one so I may as well be the pioneer!
* ...actually the main issue is more to do with my friends and family - I know of a few people who will immediately want me to build them a projector - If I can do it with parts that I can pick up from the local electronics stores then all the better!
Graham
Yeah, this ties in with what I imagined would be the case... My need for a projector is just for video. I went for the 2.5" panel for a number of reasons:
* It wouldn't suffer any degradation of quality using a condenser lens prior to the projection lens. (especially if it was a fresnel).
* The OHP style projection panels that people have had success with seem very nice but I wanted to avoid using one for both space constraints and contrast problems (as on the older ones - not checked new ones)
* I don't know anyone else who's tried it with this one so I may as well be the pioneer!
* ...actually the main issue is more to do with my friends and family - I know of a few people who will immediately want me to build them a projector - If I can do it with parts that I can pick up from the local electronics stores then all the better!
Graham
Let see if I get this straight. You get white light when your LCD is off? Could be.
When mine is completely off, it is black.
However, yours might be black when there is no signal, like when switching between inputs, e.g., video, vhs, s-video inputs.
Like I said, it was only an educated guess.
Doesn't mean your LCD is a POS.
Vince
PS, you guys got to remember, we are making something out of nothing here. Out of all the DIY projects out there, like speakers, amp, and preamps, I have not seen a single DIY projector project that shows a projected image, unless I missed it.
If you guys get anything projected and you think it looks good and are happy with it at all, you have accomplished something big.
Just alittle something to help you to keep pushing forward. I know sometimes I need to be reminded.
V.
When mine is completely off, it is black.
However, yours might be black when there is no signal, like when switching between inputs, e.g., video, vhs, s-video inputs.
Like I said, it was only an educated guess.
Doesn't mean your LCD is a POS.
Vince
PS, you guys got to remember, we are making something out of nothing here. Out of all the DIY projects out there, like speakers, amp, and preamps, I have not seen a single DIY projector project that shows a projected image, unless I missed it.
If you guys get anything projected and you think it looks good and are happy with it at all, you have accomplished something big.
Just alittle something to help you to keep pushing forward. I know sometimes I need to be reminded.
V.
Hello,
My LCD is "commercial" projection panel for ohp use but this should probably do no difference, it's still LCD. It accepts only VGA (computer anyway) signal. When there's no signal it shows logo thing with white background. when power off and no cables attached it shows / projects just white. But this doesn't matter, when boot up the computer, the background in the startup is black and it is yes, grey more than black.
Anyway, I put my non-properly working OHP fresnel lens to pieces. It actually is two lenses with smooth sides outside and inside the opposite for the smooth, what ever the word was/is.
Although they still don't work so good as an page magnifier.
Edmund optics probably says it better in the "Quick Tips for Projector Design": "The classical condenser lens system consists of two plano-convex (PCX) elements mounted convex sides together. The first lens collects the divergent light cone from the illuminator (object or projector); the second lens outputs the light as a convergent cone (image). " You probably read/knew this already though so let's get to the point:
There was a picture where these lenses a part from each other so this is where I got my idea to somehow fix my unworking fresnel, play around with them as two pieces.
I can project an image with "standard projector" setup, although I'm missing some light from the right side of the image and the light could be spreaded more evenly than it is now. But if I could keep the thing on more than one minute at a time and it wouldn't "fall" in to pieces when moving it and it could be mounted to ceiling that would be something wouldn't it?-)
And my final setup will probably be the ohp/furniture one.
I could probably post some pictures of my ugly projector (although it isn't much more than dwalls already has on his page) and some results. Although it is like 15"-25" image I have projected with this thing since my room/space is limited to play around here, the light source is weak and the image size doesn't matter too much before the thing is working properly. But I could take pictures from bigger screen but for all this I need three things:
- camera
- web space
- people to look at these pictures
Camera I can probably borrow, web space would be cool if one of you could just host the pictures, I don't want to sign up to any free webspace thing, and third thing is up to you really.
My LCD is "commercial" projection panel for ohp use but this should probably do no difference, it's still LCD. It accepts only VGA (computer anyway) signal. When there's no signal it shows logo thing with white background. when power off and no cables attached it shows / projects just white. But this doesn't matter, when boot up the computer, the background in the startup is black and it is yes, grey more than black.
Anyway, I put my non-properly working OHP fresnel lens to pieces. It actually is two lenses with smooth sides outside and inside the opposite for the smooth, what ever the word was/is.
Although they still don't work so good as an page magnifier.
Edmund optics probably says it better in the "Quick Tips for Projector Design": "The classical condenser lens system consists of two plano-convex (PCX) elements mounted convex sides together. The first lens collects the divergent light cone from the illuminator (object or projector); the second lens outputs the light as a convergent cone (image). " You probably read/knew this already though so let's get to the point:
There was a picture where these lenses a part from each other so this is where I got my idea to somehow fix my unworking fresnel, play around with them as two pieces.
I can project an image with "standard projector" setup, although I'm missing some light from the right side of the image and the light could be spreaded more evenly than it is now. But if I could keep the thing on more than one minute at a time and it wouldn't "fall" in to pieces when moving it and it could be mounted to ceiling that would be something wouldn't it?-)
And my final setup will probably be the ohp/furniture one.
I could probably post some pictures of my ugly projector (although it isn't much more than dwalls already has on his page) and some results. Although it is like 15"-25" image I have projected with this thing since my room/space is limited to play around here, the light source is weak and the image size doesn't matter too much before the thing is working properly. But I could take pictures from bigger screen but for all this I need three things:
- camera
- web space
- people to look at these pictures
Camera I can probably borrow, web space would be cool if one of you could just host the pictures, I don't want to sign up to any free webspace thing, and third thing is up to you really.
IT DOES WORK !!!!!!!!!
Well I fanally got to the prototype stage.
I started building yeterday afternoon (with cardboard)What else. After about 15 minutes I had a 72 inch screen projected on the garage door.
Granted the picture was not as bright as I had hoped but the picture was very clear, but only after I switched from my VCR as a video source to the new APEX DVD player my wife got me for Xmas. A huge improvement in projected video image.
The following is what I did;;;;;
I used my proxima 820c LCD panel (640x480) resolution with my DVD player as a video source. I mounted the LCD Panel in a cardboard box I then placed an old overhead projector fresnel lens (very rough and scratched) against the front side of the Panel. I then mounted the LOA Fluorex lamp directly behind the panel( after removing it from the stand) I then took the 8.5x11 page magnifier and mounted it to the old LOA worklight stand so I could move it easly for focusing. I cut a hole in the fron side of the box roughly the same size as the LCD panel
turned on the Fluorex lamp got the square image from the box positioned on the garagedoor a moved the Page Magnifier until the became focused.
AND THERE IT WAS """"MATRIX"""" ON THE GARAGEDOOR
72" screen for under $ lets see.
LCD Panel $99.00 (ebay)
Page Magnifer $6.00 (office depot)
Old OHP part $0.00 (recycling center)
Total cost $105.00
Granted it could use some improvement in the brightness, but I am now convinced it can be achieved.
I will try to aquire a Better fresnel lens (glass maybe). And also to modify the lighting source (overdrive it).
Well there are alot of tweeks in there that could be put to use such as Better alignment of the optics (center to center on the lenses) as well as squareing the whole thing up. I have learned from years of ameature astronomy and telescope making that the alignment of the optics is very crucial in geting a image to the eyepiece that is in perfect focus. The reason i did it in such a hurry was to see if it was actually doable
AND I NOW KNOW IT IS.
Keep up the good work, together we can do this..
TIM
Well I fanally got to the prototype stage.
I started building yeterday afternoon (with cardboard)What else. After about 15 minutes I had a 72 inch screen projected on the garage door.
Granted the picture was not as bright as I had hoped but the picture was very clear, but only after I switched from my VCR as a video source to the new APEX DVD player my wife got me for Xmas. A huge improvement in projected video image.
The following is what I did;;;;;
I used my proxima 820c LCD panel (640x480) resolution with my DVD player as a video source. I mounted the LCD Panel in a cardboard box I then placed an old overhead projector fresnel lens (very rough and scratched) against the front side of the Panel. I then mounted the LOA Fluorex lamp directly behind the panel( after removing it from the stand) I then took the 8.5x11 page magnifier and mounted it to the old LOA worklight stand so I could move it easly for focusing. I cut a hole in the fron side of the box roughly the same size as the LCD panel
turned on the Fluorex lamp got the square image from the box positioned on the garagedoor a moved the Page Magnifier until the became focused.
AND THERE IT WAS """"MATRIX"""" ON THE GARAGEDOOR
72" screen for under $ lets see.
LCD Panel $99.00 (ebay)
Page Magnifer $6.00 (office depot)
Old OHP part $0.00 (recycling center)
Total cost $105.00
Granted it could use some improvement in the brightness, but I am now convinced it can be achieved.
I will try to aquire a Better fresnel lens (glass maybe). And also to modify the lighting source (overdrive it).
Well there are alot of tweeks in there that could be put to use such as Better alignment of the optics (center to center on the lenses) as well as squareing the whole thing up. I have learned from years of ameature astronomy and telescope making that the alignment of the optics is very crucial in geting a image to the eyepiece that is in perfect focus. The reason i did it in such a hurry was to see if it was actually doable
AND I NOW KNOW IT IS.
Keep up the good work, together we can do this..
TIM
Pictures to follow
Oh! almost forgot,,,,,
I will be posting pictures on my Bigscreen webpage
you can get there at bstv.timlewellyn.com
I hope to have them posted later this evening.
They are not the greatest pics due to the poor quality of the camera I was using. But hope to post better ones in the future.
Oh! almost forgot,,,,,
I will be posting pictures on my Bigscreen webpage
you can get there at bstv.timlewellyn.com
I hope to have them posted later this evening.
They are not the greatest pics due to the poor quality of the camera I was using. But hope to post better ones in the future.
WEB SPACE
Hi all, Vince, Bitch....
If you need web space give me a shout - graham@painlesswebdesign.com
I set up the mini site on www.painlesswebdesign.com/lcd for that purpose so send them my way!
Graham
Hi all, Vince, Bitch....
If you need web space give me a shout - graham@painlesswebdesign.com
I set up the mini site on www.painlesswebdesign.com/lcd for that purpose so send them my way!
Graham
Web page.
Hey guys, I just created a small website on geocities and will be posting some pics of my project soon. www.geocities.com/zark5150
Hey guys, I just created a small website on geocities and will be posting some pics of my project soon. www.geocities.com/zark5150
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