Right, I see a lot of OHP in here and I’ve toyed around with it, with fair results.
However, are there any people out there that can help spawn a new discussion about other design and approaches?
Or is OHP the only way to go?
However, are there any people out there that can help spawn a new discussion about other design and approaches?
Or is OHP the only way to go?
OHP vs. Build from scratch
Hello yF, and yes there are other ways. Most have to do with building your own box and fitting the necessary lenses into it. It requires a light source, proper reflector, cooling, different lenses, and proper spacing. Some are working on using lenses that were originally made for projection tvs (do a search on this site with the word "delta" and you should turn up a few interesting leads). Others use page magnifiers or fresnels from OHP's along with a projection lens of some sort. The reason so many people seem to gravitate towards the OHP route is that everything is already figured out for you...the lense is the proper distance (and easily adjustable) the light is fixed in the proper place and at the proper distance, the fresnel is at the right place, and the cooling is already there. Disadvantages appear to be the look and size, the lack of enough "brightness" and color tone of the light output, and the noise of the cooling fans. Hope this helps, I'm sure there are more ways out there, but these seem to be the most common. You might search out "Zarks" site as well as "Dreamweaver"s, they both were building from parts. Take Care, Smoke Eater
Hello yF, and yes there are other ways. Most have to do with building your own box and fitting the necessary lenses into it. It requires a light source, proper reflector, cooling, different lenses, and proper spacing. Some are working on using lenses that were originally made for projection tvs (do a search on this site with the word "delta" and you should turn up a few interesting leads). Others use page magnifiers or fresnels from OHP's along with a projection lens of some sort. The reason so many people seem to gravitate towards the OHP route is that everything is already figured out for you...the lense is the proper distance (and easily adjustable) the light is fixed in the proper place and at the proper distance, the fresnel is at the right place, and the cooling is already there. Disadvantages appear to be the look and size, the lack of enough "brightness" and color tone of the light output, and the noise of the cooling fans. Hope this helps, I'm sure there are more ways out there, but these seem to be the most common. You might search out "Zarks" site as well as "Dreamweaver"s, they both were building from parts. Take Care, Smoke Eater
Another thing:
With the OHP route, the LCD panels are readily available thru ebay for less than $100, and the resolution is almost always at least 640x480, which I think most people will agree is the minumum for projecting a large image. 800x600 (or even 1024x768) OHP LCD panels are available, but they cost $250-$350. OHPs that put out 3500-5000 lumens are also available for about $100.
The people that are building their own projectors have, for the most part, been using either the same LCDs designed for use with an OHP, or smaller LCDs that came from some other use (mobile video, game packs, etc). The former is probably the easiest, but it could be argued that they are just re-inventing the OHP setup. The latter struggle with high costs and lower resolutions, plus the added complexity (sometimes) of separating the LCD from the backlight.
Additionally, the former group almost always ends up with very large projectors as a result of having to illuminate the larger LCD panel. The latter has about the opposite problem, where they have to find an LCD panel small enough to fit inside the diameter of their projection lens.
One common factor in both these groups is the interest in improving the light source beyond what the common OHP provides. Even at 4000-5000 lumens, the image is usually not comfortably visible in an illuminated room. This is due to the fact that the LCD panel only passes about 10-15% of the available light. In order to be comfortably visible in an illuminated room, you need just over 1000 lumens on the screen. Of course, "comfortably visible" is subjective.
There is a 3rd group who are probably the most cutting-edge, who are tearing down hi-res computer monitors to make VERY high resolution (up to 1600x1200) projectors. This is undoubtedly the most complex (and expensive) path, because it involves messing with some very delicate cabling (and in some cases actually making custom cabling), and having to obtain expensive driver boards.
The last group are those that plunk an LCD panel on top of a OHP and call it good. They usually end up spending the $200+ for a metal-halide driven OHP on ebay, which is the easiest way to crank up the lumens for this setup.
Me, I'm 90% in the last group, but I don't want to spend big bucks on a MH OHP and replacement bulbs. I'm taking the easy route of employing an existing OHP, but I'm trying to come up with an alternate light source. Essentially, this means mounting a metal-halide bulb in an OHP that was originally a halogen. I'm using the cheapest of the cheap, a 2500-lumen 3M OHP that usually goes for about $25 on ebay (actually, I got mine for free with my LCD panel), and I'm trying to spend less than $150 on the light source. Of course, this means that I'm gonna have a big honkin gadget sticking out of the back of my OHP, but I'll use the money I save to calm my offended senses.
With the OHP route, the LCD panels are readily available thru ebay for less than $100, and the resolution is almost always at least 640x480, which I think most people will agree is the minumum for projecting a large image. 800x600 (or even 1024x768) OHP LCD panels are available, but they cost $250-$350. OHPs that put out 3500-5000 lumens are also available for about $100.
The people that are building their own projectors have, for the most part, been using either the same LCDs designed for use with an OHP, or smaller LCDs that came from some other use (mobile video, game packs, etc). The former is probably the easiest, but it could be argued that they are just re-inventing the OHP setup. The latter struggle with high costs and lower resolutions, plus the added complexity (sometimes) of separating the LCD from the backlight.
Additionally, the former group almost always ends up with very large projectors as a result of having to illuminate the larger LCD panel. The latter has about the opposite problem, where they have to find an LCD panel small enough to fit inside the diameter of their projection lens.
One common factor in both these groups is the interest in improving the light source beyond what the common OHP provides. Even at 4000-5000 lumens, the image is usually not comfortably visible in an illuminated room. This is due to the fact that the LCD panel only passes about 10-15% of the available light. In order to be comfortably visible in an illuminated room, you need just over 1000 lumens on the screen. Of course, "comfortably visible" is subjective.
There is a 3rd group who are probably the most cutting-edge, who are tearing down hi-res computer monitors to make VERY high resolution (up to 1600x1200) projectors. This is undoubtedly the most complex (and expensive) path, because it involves messing with some very delicate cabling (and in some cases actually making custom cabling), and having to obtain expensive driver boards.
The last group are those that plunk an LCD panel on top of a OHP and call it good. They usually end up spending the $200+ for a metal-halide driven OHP on ebay, which is the easiest way to crank up the lumens for this setup.
Me, I'm 90% in the last group, but I don't want to spend big bucks on a MH OHP and replacement bulbs. I'm taking the easy route of employing an existing OHP, but I'm trying to come up with an alternate light source. Essentially, this means mounting a metal-halide bulb in an OHP that was originally a halogen. I'm using the cheapest of the cheap, a 2500-lumen 3M OHP that usually goes for about $25 on ebay (actually, I got mine for free with my LCD panel), and I'm trying to spend less than $150 on the light source. Of course, this means that I'm gonna have a big honkin gadget sticking out of the back of my OHP, but I'll use the money I save to calm my offended senses.
Well...
I’ve also started with an OHP and an OHP lcd panel. Good resolution, bad light.
So I’m thinking to move to LCD modules, strip the backlight off and plant the whole thing in a smaller box.
I few things I have problems with are;
* Bad resolution: I Haven’t found a panel yet that supports 640*840 on 5”
* Ports : Most of these smaller displays only work on a standard composite video signal
And offcourse.. Stripping these panels holds risks of messing the panel up and see your money go up in err... Crystals... :|
Also.. What Dot pitch? Contrast ratio?
Since I didn’t investigate much and just went ahead and bought an OHP LCD panel I’m not sure what to choose now, what cruelpits to avoid when selecting an LCD panel.
Anybody with some info on that?
I’ve also started with an OHP and an OHP lcd panel. Good resolution, bad light.
So I’m thinking to move to LCD modules, strip the backlight off and plant the whole thing in a smaller box.
I few things I have problems with are;
* Bad resolution: I Haven’t found a panel yet that supports 640*840 on 5”
* Ports : Most of these smaller displays only work on a standard composite video signal
And offcourse.. Stripping these panels holds risks of messing the panel up and see your money go up in err... Crystals... :|
Also.. What Dot pitch? Contrast ratio?
Since I didn’t investigate much and just went ahead and bought an OHP LCD panel I’m not sure what to choose now, what cruelpits to avoid when selecting an LCD panel.
Anybody with some info on that?
What LCD Panel?
Well.. I've ordered a 4" panel
( http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Product_ID=4686&CATID=44 )
I hope this will give me a clear picture.
What I'm after now is to make the whole thing compact and quiet.
Does anybody know wheter this order was a smart move? 😕
Anybody that knows of another panel in the same price range, i would order it too and compare them.
I think I can make it as small as a slide projector, I would mod the projector my grandparents have lying around on the attick.
Well.. I've ordered a 4" panel
( http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Product_ID=4686&CATID=44 )
I hope this will give me a clear picture.
What I'm after now is to make the whole thing compact and quiet.
Does anybody know wheter this order was a smart move? 😕
Anybody that knows of another panel in the same price range, i would order it too and compare them.
I think I can make it as small as a slide projector, I would mod the projector my grandparents have lying around on the attick.
Re: What LCD Panel?
That lcd does not have a very high res, but you will get a good, but not huge picture. I would suggest for a first timer, getting the 5" from parts express. If you may also want to consider a nview spectra c or plus as this has very good res and requires no disasembly. I will say that the parts expresss screens are simple to take apart. All you need is a small screw driver and every thing slides apart with not cables/chips covering the screen. Once you get them dissasembed, you can mount them to a piece of glass you two dots of superglue for added strength. Make sure you dont flex the ribons either. I did have a 5" lcd from PE, but i don't really want to talk about what i did to it. Daaaa... I just bought an nview, so I i'll post my results later. Good luck.
yF said:
That lcd does not have a very high res, but you will get a good, but not huge picture. I would suggest for a first timer, getting the 5" from parts express. If you may also want to consider a nview spectra c or plus as this has very good res and requires no disasembly. I will say that the parts expresss screens are simple to take apart. All you need is a small screw driver and every thing slides apart with not cables/chips covering the screen. Once you get them dissasembed, you can mount them to a piece of glass you two dots of superglue for added strength. Make sure you dont flex the ribons either. I did have a 5" lcd from PE, but i don't really want to talk about what i did to it. Daaaa... I just bought an nview, so I i'll post my results later. Good luck.
Which one do you fancy?
there are quite some 5"+ LCD's at partsexpress, anyone you have experience with, or where you know of that it's easy to strip?
there are quite some 5"+ LCD's at partsexpress, anyone you have experience with, or where you know of that it's easy to strip?
I think he suggested a 5" panel because you can use it w/ a 5" projector lens (like the Delta) w/o a fresnel. That does make things a lot easier.
Yup. Thats what I ment. Because you went with the 4" lcd, for a projector lens, i would go with the 4-1/2" DIA. FUJINON TV PROJ. LENS from http://www.surplusshed.com/pages/Lenses.html. This one a a little bigger than 4", so you could just make a border around the extra space, and you would not have to worry about the edges being cut off.
Hello 5"
I was quick to cancel the 4" and I've ordered the 5.6"
( http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Product_ID=16107&CATID=44 ) after I saw that the resolutions wouldn't be good 😉
This thing has good response time and ought to do the trick.
Been busy thinking out a way to improve the quality of black.
I remember my mother saying she saw a sort of plastic than could change it's tint depending on what light shines on it.
This can be an improvement of quality
Another thing that might help is mounting a second LCD...
But then you'd prolly need more light, which adds to the cost and pay for another lcd.
I'm going to think what else i can do
I was quick to cancel the 4" and I've ordered the 5.6"
( http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Product_ID=16107&CATID=44 ) after I saw that the resolutions wouldn't be good 😉
This thing has good response time and ought to do the trick.
Been busy thinking out a way to improve the quality of black.
I remember my mother saying she saw a sort of plastic than could change it's tint depending on what light shines on it.
This can be an improvement of quality
Another thing that might help is mounting a second LCD...
But then you'd prolly need more light, which adds to the cost and pay for another lcd.
I'm going to think what else i can do
Blastoff
It's official 🙂
My order is in the mail, one 5.6" LCD coming to Europe!
I've been quite busy too.. I modded the slide projector my grandparents have/had 😎
I've cut out a transparent sheet of plastic matching the size of the lcd. After some tweeking I got a clear picture (of a stickman with a house and an out-of-proporion sun🙂 )
Tommorow I'm gonna go to downtown Brussels to visit a street which has loads of Photograhic shops (i dunno how they are called in english, but you get the point)
There I hope to find a parabolic mirror because the slide projector is based upon a halogen bulb that just won't cutt it and a lens, I'm hoping to get a better one than the one fixed on the projector.
I'm gettin' there!
It's official 🙂
My order is in the mail, one 5.6" LCD coming to Europe!
I've been quite busy too.. I modded the slide projector my grandparents have/had 😎
I've cut out a transparent sheet of plastic matching the size of the lcd. After some tweeking I got a clear picture (of a stickman with a house and an out-of-proporion sun🙂 )
Tommorow I'm gonna go to downtown Brussels to visit a street which has loads of Photograhic shops (i dunno how they are called in english, but you get the point)
There I hope to find a parabolic mirror because the slide projector is based upon a halogen bulb that just won't cutt it and a lens, I'm hoping to get a better one than the one fixed on the projector.
I'm gettin' there!
Re: Hello 5"
If you wanted great quality, and had tones of money to blow, you could do 3 screens one for red, green, and blue. I suppose you would need some nice mirror setups, or 3 lenses from a old fassion crt projector.
yF said:
If you wanted great quality, and had tones of money to blow, you could do 3 screens one for red, green, and blue. I suppose you would need some nice mirror setups, or 3 lenses from a old fassion crt projector.
Oh dear...
oh boy.. transporting stuff from the states to europe takes ages!
A whole week, this bl0wz 🙂
I could make a projector following the CRT Proj. concept, but this would increase the price for a DIY alot.
I've been busy looking at a way to get black to appear black and not dark gray and so far I haven't been able to come up with something that would be able to do that.
There are lenzes that can do a bit of colour tweaking, but they are expensive. Tonight I'll look into the concept of these lenzes to see whether I can't build one myself.
May your LCD's arrive quickly!
oh boy.. transporting stuff from the states to europe takes ages!
A whole week, this bl0wz 🙂
I could make a projector following the CRT Proj. concept, but this would increase the price for a DIY alot.
I've been busy looking at a way to get black to appear black and not dark gray and so far I haven't been able to come up with something that would be able to do that.
There are lenzes that can do a bit of colour tweaking, but they are expensive. Tonight I'll look into the concept of these lenzes to see whether I can't build one myself.
May your LCD's arrive quickly!
yf
yf, ge moet proberen iemand in de us te vinden die spullen naar u toestuurt!
een truukske is dat zender en bestemmeling de zelfde naam en coordinaten hebben
alsof ge wilt zeggen tegen de post en alle doeane dat ge het zelf hebt opgestuurd vanuit amerika naar uw eigen adres!
tis dan precies alsof ge het al betaald hebt in de US met uw eigen centen. heel dikwijls gaat dat snel en maakt de doeane niet veel ambras!
tis dak ik het u gezegd hebt!
Jean-Pierre
yf, ge moet proberen iemand in de us te vinden die spullen naar u toestuurt!
een truukske is dat zender en bestemmeling de zelfde naam en coordinaten hebben
alsof ge wilt zeggen tegen de post en alle doeane dat ge het zelf hebt opgestuurd vanuit amerika naar uw eigen adres!
tis dan precies alsof ge het al betaald hebt in de US met uw eigen centen. heel dikwijls gaat dat snel en maakt de doeane niet veel ambras!
tis dak ik het u gezegd hebt!
Jean-Pierre
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