I was very blessed to find a 5" Sharp LQ6NC01 240x720 for around $45 on E-Bay (not including shipping).
If I didn't get that, I would probably go with the small 2" spy-monitor TFT from Hong Kong -- those look really cool.
My goal is silent, cool, small, and portable. I want to try and stay away from fresnels if at all possible.
Just out of curiosity, how many LED bulbs do you think I would need? I have a hard time converting from watts to mcd to lumens and all else.
Thanks!
--Clint
If I didn't get that, I would probably go with the small 2" spy-monitor TFT from Hong Kong -- those look really cool.
My goal is silent, cool, small, and portable. I want to try and stay away from fresnels if at all possible.Just out of curiosity, how many LED bulbs do you think I would need? I have a hard time converting from watts to mcd to lumens and all else.
Thanks!
--Clint
Re: zardoz!
Hi Ax..try happy harry's in Burnside, he's a bit expensive tho. There is another guy very near him also but I dont know his name. I have a few transformers and such, missing mogul bases but as far as I know they work. If you are interested let me know, I got my "reflector" from Saan's (big SST bowls...tested one last night with good result) I'm debateing over 2 choices till I get my panel this week. What do you have for gear? Maybe we can help each other out and get something accomplished. I have a few optics/electrics but am actively seeking more, and may part with some of the stuff I do have.
zardoz
Axeman said:zardoz- You mentioned that you found some HID lights/ballasts at a local building wrecker... I am also in Nova Scotia. Mind giving up exactly where you came across these lights??
Axeman
Hi Ax..try happy harry's in Burnside, he's a bit expensive tho. There is another guy very near him also but I dont know his name. I have a few transformers and such, missing mogul bases but as far as I know they work. If you are interested let me know, I got my "reflector" from Saan's (big SST bowls...tested one last night with good result) I'm debateing over 2 choices till I get my panel this week. What do you have for gear? Maybe we can help each other out and get something accomplished. I have a few optics/electrics but am actively seeking more, and may part with some of the stuff I do have.
zardoz
Well...
So anyway, I won the auction for the 5.7 inch LCD $45 for a 240x740 Sharp is good for my first experimental LCD.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=21517&item=1944678193&rd=1
However, considering that I want to use LED's as my light source, I probably can't use fresnels because of the light loss. Therefore, I need to keep with normal optics. However, this is a problem. It wouldn't be so bad if it was a normal 5" LCD as advertised, but it's 5.7 inch. I knew that before bidding, but I didn't realize or something that I needed to have 6 inch diameter high-power double-concave lenses. I'm thinking my best bet is likely to find 6 inch magnifying glasses, although they are hardly projection optics quality, they may have to do. However, I haven't been able to find any of them anywhere. Does anyone else have experience with using completely non-fresnel optics, and where do you find big ones? I'd like to spend <$50 for all my optics, although I'm not sure that's possible.
Thanks alot! Keep up the great work guys!
--Clint
So anyway, I won the auction for the 5.7 inch LCD
$45 for a 240x740 Sharp is good for my first experimental LCD.http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=21517&item=1944678193&rd=1
However, considering that I want to use LED's as my light source, I probably can't use fresnels because of the light loss. Therefore, I need to keep with normal optics. However, this is a problem. It wouldn't be so bad if it was a normal 5" LCD as advertised, but it's 5.7 inch. I knew that before bidding, but I didn't realize or something that I needed to have 6 inch diameter high-power double-concave lenses. I'm thinking my best bet is likely to find 6 inch magnifying glasses, although they are hardly projection optics quality, they may have to do. However, I haven't been able to find any of them anywhere. Does anyone else have experience with using completely non-fresnel optics, and where do you find big ones? I'd like to spend <$50 for all my optics, although I'm not sure that's possible.
Thanks alot! Keep up the great work guys!
--Clint
Re: Well...
HanClinto said:So anyway, I won the auction for the 5.7 inch LCD
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=21517&item=1944678193&rd=1
However, considering that I want to use LED's as my light source, I probably can't use fresnels because of the light loss. Therefore, I need to keep with normal optics. However, this is a problem. It wouldn't be so bad if it was a normal 5" LCD as advertised, but it's 5.7 inch. I knew that before bidding, but I didn't realize or something that I needed to have 6 inch diameter high-power double-concave lenses. I'm thinking my best bet is likely to find 6 inch magnifying glasses, although they are hardly projection optics quality, they may have to do. However, I haven't been able to find any of them anywhere. Does anyone else have experience with using completely non-fresnel optics, and where do you find big ones? I'd like to spend <$50 for all my optics, although I'm not sure that's possible.
Try surplus shed they have some big (7 inch plus ) PCX lens's
zardoz
Thanks alot! Keep up the great work guys!
--Clint
Thanks!
Thanks Zardoz! They've got some great-looking 7.5" diameter 20" FL magnifying lenses that look like they'll do the trick.
I stayed up all night (literally) looking at this stuff and trying to figure it out. I know I can calculate the lens focal points and such once I get the right layout that I need. I drew a quick picture to see if this is right, but I don't think it is. I think this would give me a point on the screen. But if it's larger, wouldn't it just be an image out of focus? I know you need to have the focal point on the spot that you're projecting to. I'm sorry, I'm just very confused at the moment.
Geocities hates image re-referencing. Here's the picture.wronglayout.JPG
Thanks for your help!
--Clint
Thanks Zardoz! They've got some great-looking 7.5" diameter 20" FL magnifying lenses that look like they'll do the trick.
I stayed up all night (literally) looking at this stuff and trying to figure it out. I know I can calculate the lens focal points and such once I get the right layout that I need. I drew a quick picture to see if this is right, but I don't think it is. I think this would give me a point on the screen. But if it's larger, wouldn't it just be an image out of focus? I know you need to have the focal point on the spot that you're projecting to. I'm sorry, I'm just very confused at the moment.
Geocities hates image re-referencing. Here's the picture.wronglayout.JPG
Thanks for your help!
--Clint
HanClinto
I'm using a 12 inch laptop panel that hasnt arrived yet. I myself still dont have a really good handle on the optics I'm going to need. I do have a number of elements that I took from CRT lens packs, but not sure if I have anything that I can use. I saw the big PCX from surplus shed and am fairly sure I'll be getting a couple of them. At their prices I might get some other stuff just to have around to experiment with.
zardoz
I'm using a 12 inch laptop panel that hasnt arrived yet. I myself still dont have a really good handle on the optics I'm going to need. I do have a number of elements that I took from CRT lens packs, but not sure if I have anything that I can use. I saw the big PCX from surplus shed and am fairly sure I'll be getting a couple of them. At their prices I might get some other stuff just to have around to experiment with.
zardoz
LED Light calculation update
Here's an update on calculations that I've made for the feasability of using the lights available on http://www.superbrightleds.com/1157.htm
Going off the spec-sheet for the bulbs... the axial luminous intensity (lv) unit is in mcd (I'm assuming millicandles). A candle is the same thing as a lumen (according to my Pocket Ref), and each bulb is 78720 mcd, or 78.720 lumens.
78.72 lumens = .11808 Watts
12 bulbs costs $84 ($89 shipped)... which is roughly my limit on lighting at this point.
12*.11808 = 9.918 watts
$84 for a perfectly cool and silent 10 watt bulb... that sounds like nothing compared to these 400 watt systems that people are running. These bulbs have a viewing angle of 12 degrees though... I imagine that means that most of the light is within a 12 degree cone. Would the direction of the light help that much? I can't imagine directed light helping out more than doubling the effective brightness, so that would still mean it's like a 20 watt bulb. That's nothing. That's a very dim reading light for my clip-on. *sigh*. Am I doing my math right? It looks like I might be using a LOA worklight afterall.
Here's an update on calculations that I've made for the feasability of using the lights available on http://www.superbrightleds.com/1157.htm
Going off the spec-sheet for the bulbs... the axial luminous intensity (lv) unit is in mcd (I'm assuming millicandles). A candle is the same thing as a lumen (according to my Pocket Ref), and each bulb is 78720 mcd, or 78.720 lumens.
78.72 lumens = .11808 Watts
12 bulbs costs $84 ($89 shipped)... which is roughly my limit on lighting at this point.
12*.11808 = 9.918 watts
$84 for a perfectly cool and silent 10 watt bulb... that sounds like nothing compared to these 400 watt systems that people are running. These bulbs have a viewing angle of 12 degrees though... I imagine that means that most of the light is within a 12 degree cone. Would the direction of the light help that much? I can't imagine directed light helping out more than doubling the effective brightness, so that would still mean it's like a 20 watt bulb. That's nothing. That's a very dim reading light for my clip-on. *sigh*. Am I doing my math right? It looks like I might be using a LOA worklight afterall.
A lens vs fresnel question
What is everyone's experience with fresnel lenses versus using a large cvx lens. I can buy a fresnel for my 5.6" screen for less than $10, or I can buy a 7" cvx lense for $30. I can't imagine that fresnels have great optical charictaristics, and it seems that the light would refract much better with a real cvx lense... but I really don't know if the difference is noticable. Thoughts from anyone?
--Clint
What is everyone's experience with fresnel lenses versus using a large cvx lens. I can buy a fresnel for my 5.6" screen for less than $10, or I can buy a 7" cvx lense for $30. I can't imagine that fresnels have great optical charictaristics, and it seems that the light would refract much better with a real cvx lense... but I really don't know if the difference is noticable. Thoughts from anyone?
--Clint
mcd is <a href="http://physics.nist.gov/cuu/Units/candela.html">millicandela</a>, not straight candlepower. <a href="http://www.schorsch.com/kbase/glossary/luminous_intensity.html"> A candela is 1 lumen per steradian.</a>
Careful of the difference btw <i>spherical</i> candela and <i>beam</i> candela. Most contemporary lights are measured in spherical cd, whereas LEDs are measured in beam cd.
Calculation for lumens from beam cd is :
<a href="http://dcwi.com/~nybarra/LED.html">( 1 - cos(beam_width/2)) * 2pi * cd </a>
so, for 78,720 mcd ...
( 1 - cos(6) ) * 2pi * 78.72 = 2.71 lumens
This sounds weak because it's calculated on the basis of the width of the beam. This measurement may be inaccurate, tho, because the "beam_width" is supposed to be the width of the beam at half-power. IOW, it's the radius at which the intensity of the beam is half of it's maximum.
Also, with a 12deg beam, your distance to the panel would have to be:
tan( beam_width/2 ) = ( panel_diagonal/2 )/ depth
so for an 8.4" diagonal panel, you would have to place the 12deg light source almost 40 inches away (39.96, TBE).
As always, your mileage may vary, but that's the math as far as I know.
Careful of the difference btw <i>spherical</i> candela and <i>beam</i> candela. Most contemporary lights are measured in spherical cd, whereas LEDs are measured in beam cd.
Calculation for lumens from beam cd is :
<a href="http://dcwi.com/~nybarra/LED.html">( 1 - cos(beam_width/2)) * 2pi * cd </a>
so, for 78,720 mcd ...
( 1 - cos(6) ) * 2pi * 78.72 = 2.71 lumens
This sounds weak because it's calculated on the basis of the width of the beam. This measurement may be inaccurate, tho, because the "beam_width" is supposed to be the width of the beam at half-power. IOW, it's the radius at which the intensity of the beam is half of it's maximum.
Also, with a 12deg beam, your distance to the panel would have to be:
tan( beam_width/2 ) = ( panel_diagonal/2 )/ depth
so for an 8.4" diagonal panel, you would have to place the 12deg light source almost 40 inches away (39.96, TBE).
As always, your mileage may vary, but that's the math as far as I know.
Thanks!
Sweet! Thanks for the calculation info.
If you wanted to stay closer to the screen... what about using something like this?
Those are available from www.3dlens.com, and for a fairly cheap price too ($2.06 for 1-4 units). With an array of those, you could do something which was proposed a month or so ago in a different forum, and have each lamp illuminate a smaller section of the LCD. Hopefully crossover would eliminate any dark spots.
What's your opinion on that, Rolm?
Thanks alot! Keep up the great work everybody!
--Clint
Sweet! Thanks for the calculation info.
If you wanted to stay closer to the screen... what about using something like this?
An externally hosted image should be here but it was not working when we last tested it.
.jpg){kind=link}
Those are available from www.3dlens.com, and for a fairly cheap price too ($2.06 for 1-4 units). With an array of those, you could do something which was proposed a month or so ago in a different forum, and have each lamp illuminate a smaller section of the LCD. Hopefully crossover would eliminate any dark spots.
What's your opinion on that, Rolm?
Thanks alot! Keep up the great work everybody!
--Clint
<img src="http://www.3dlens.com/media/fresnel_408(large).jpg">
Hmm, interesting. You would still have to use multiple light sources per image lens. If you were looking to cover your LCD with ((I'm guessing on the dimensions here) a 4x3 grid from this multi-lens, and you were shooting to put 4000 lumens on the LCD, then you would need 4000/(4x3) lumens per image lens, or 333.33 lumens each. And then there's overlap as each of the spherical beam's edges touch the image lenses adjoining the one it's aiming at, which means that each beam needs to be run through an apeture first; and then there's the problem of the different beam angles as a result of using multiple LEDs...
Interesting, but I think it would be alot of engineering to get it to work right. And I still think the LEDs are underpowered.
That being said, I have VERY little first-hand experience with hi-output LEDs, so I could be totally wrong on the lumen characteristics (that is, perhaps there is some magical way that LEDs get more bang for the buck).
It would be VERY cool if someone could make it work, though. The coolness factor of these LEDs over ones previously discussed on this BB is that they are already linked up, and they come with a nice 1157 socket attached. Most of the complexity of the previous idea was having to wire all the LEDs up.
Hmm, interesting. You would still have to use multiple light sources per image lens. If you were looking to cover your LCD with ((I'm guessing on the dimensions here) a 4x3 grid from this multi-lens, and you were shooting to put 4000 lumens on the LCD, then you would need 4000/(4x3) lumens per image lens, or 333.33 lumens each. And then there's overlap as each of the spherical beam's edges touch the image lenses adjoining the one it's aiming at, which means that each beam needs to be run through an apeture first; and then there's the problem of the different beam angles as a result of using multiple LEDs...
Interesting, but I think it would be alot of engineering to get it to work right. And I still think the LEDs are underpowered.
That being said, I have VERY little first-hand experience with hi-output LEDs, so I could be totally wrong on the lumen characteristics (that is, perhaps there is some magical way that LEDs get more bang for the buck).
It would be VERY cool if someone could make it work, though. The coolness factor of these LEDs over ones previously discussed on this BB is that they are already linked up, and they come with a nice 1157 socket attached. Most of the complexity of the previous idea was having to wire all the LEDs up.
For anyone interested...
For anyone interested I moved my rantings about super-bright white LED's over to a new thread. I actually just found some cool stuff in this area, with some neat calculations in it.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=8750
Keep running the imagination station.
--Clint
For anyone interested I moved my rantings about super-bright white LED's over to a new thread. I actually just found some cool stuff in this area, with some neat calculations in it.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=8750
Keep running the imagination station.
--Clint
Have you made a good projector using leds? I belive it can be done. When i simply placed my lce screen on the projeciton lens (delta IV), i projected a 5-6 foot imgae using only the lcds built in backlight. Using the same principals as how backlights for lcds are made, i plan to to make a "super powerful backlight." This way I will only have my lcd attached to my projector lens, and no huge box full of lights and fans. I know i sound like a neophite, but i have done many tests and what not with an lcd and delta Iv.
thanks
verbose
thanks
verbose
HanClinto said:I was very blessed to find a 5" Sharp LQ6NC01 240x720 for around $45 on E-Bay (not including shipping).
If I didn't get that, I would probably go with the small 2" spy-monitor TFT from Hong Kong -- those look really cool.
Just out of curiosity, how many LED bulbs do you think I would need? I have a hard time converting from watts to mcd to lumens and all else.
Thanks!
--Clint
read my thread
http://www.diyaudio.com/forums/showthread.php?threadid=8739&goto=newpost
I am also going for the "small DIY pj." I have done it, but i need to modify the backlight somehow... LEDs are my first choice.
Hello Everyone
I am new to this forum and I have built a TV projector which is down now since it was temporary. I was going to build a more permanent one, but since I fell into this forum by mistake I have changed my mind and I will build a LCD projector instead.
First off Im just a bumkin from Alabama hehe but I have smarts. And Im excited now about this LCD projector. As of now I wont be building this Cause IM going to wait until I upgrade my video camera. And use the one I have now for some parts.
Ok now that I have introduced myself I have a ? concerning the letter boxing you guys are doing to your LCD's how and why is white light coming from your projector isnt it letter boxed from your source such as the dvd.
When I dismantle my camera it has features that I may or may not be able to use like backlight and exposure and the connection devices.....but how do I know if the LCD is going to be good enough. I have the spec sheet that came with the user's manual. But I cant get crap froim them.
Doug
I am new to this forum and I have built a TV projector which is down now since it was temporary. I was going to build a more permanent one, but since I fell into this forum by mistake I have changed my mind and I will build a LCD projector instead.
First off Im just a bumkin from Alabama hehe but I have smarts. And Im excited now about this LCD projector. As of now I wont be building this Cause IM going to wait until I upgrade my video camera. And use the one I have now for some parts.
Ok now that I have introduced myself I have a ? concerning the letter boxing you guys are doing to your LCD's how and why is white light coming from your projector isnt it letter boxed from your source such as the dvd.
When I dismantle my camera it has features that I may or may not be able to use like backlight and exposure and the connection devices.....but how do I know if the LCD is going to be good enough. I have the spec sheet that came with the user's manual. But I cant get crap froim them.
Doug
Well I was informed in another thread that it wouldnt be feasible to use any of the parts from the camera and just to sell it.
And if this doesnt fit this thread Sorry Im new to this forum.
And besides its all kind of jumbled to me. Wish it was catagorized then maybe subcatagorized.
Or may be a definition of the titles of the threads. Guess I ll come here when i get started on my project but everyone is so far ahead.
And if this doesnt fit this thread Sorry Im new to this forum.
And besides its all kind of jumbled to me. Wish it was catagorized then maybe subcatagorized.
Or may be a definition of the titles of the threads. Guess I ll come here when i get started on my project but everyone is so far ahead.
Wellcome! You are'nt too far behind us...my project has suffered numerous delays due to the deploreable courier services, still waiting for my LCD to arrive. I'd make sure you know the camera's res on that panel, I'm guessing it might be low. If it is? I'd have to agree... sell it and use the bucks to get some more appropriate gear.
I do agree, the threads are a bit jumbled, but this sort of "forces" people to read as many as they can stomach in order to keep from asking questions that might be ignored. You've got the bug now so learn all you can before you rip down your cam and maybe waste it.
zardoz
I do agree, the threads are a bit jumbled, but this sort of "forces" people to read as many as they can stomach in order to keep from asking questions that might be ignored. You've got the bug now
so learn all you can before you rip down your cam and maybe waste it.zardoz