So the deal is that I am about to make my first LCD projector and though I've been reading this forum for a few weeks, I find lots of information confusing. When there is a new thread, the first replies are simple, but then come more advanced users who introduce many details and the discussion becomes confusing or even off-topic. This is OK for people who are experts, but for me not yet. This is why I must start this newbie thread. The questions are straightforward and numerous.
THE POSSIBILITIES:
So first of all my funds are limited to 300$ and I hope to make it within that sum.
I don't have access to additional ribbon cables, controller boards and I haven't even come across a 15" fresnel yet (most are smaller). So my hardware possibilities are basic.
THE NEEDS:
I need a projector that will be used for movies and maybe some browsing/gaming.
The size of the projected image that I want to achieve is around 6 feet on the horizontal side.
Size of the projector housing doesn't matter as I have a big house.
I don't have ambitions to have a bright image even during the day 🙂. Comfortable evening viewing is enough.
THE SETUP:
This is what I have in my mind.
My plan is to use a spherical salad bowl 13" or maybe even 15" in diameter. I plan to make it as big as possible in order to cover most of the LCD with light. Other benefits are big difference in size of filament and reflector which gives better sharpness. I guess that such a big reflector will also give better light output as compared to a small one. A big reflector also runs colder because of better heat dissipation.
I plan to use a automotive halogen bulb (100W) as they are compact, very cheap and easy to buy. I don't have access to these specific bulbs you talk about. In the future, if my setup works well, I will switch to a HID (discharge) bulb. I won't have to change basically anything in my setup. Just the bulb mount. This would give me 30% more light when compared to a 100W bulb while only using 35W of power.
The next part is the UV filter. I plan to use photo and film industry products such as www.rosco.com . You can buy all kinds of filters in big sheets. They meet photography standards of course so if you plan to change the tint of the image, just select the right product and expect stable results. They also make their filters in heat proof versions. They have mylar, IR filters etc... So my plan is to block heat from affecting the fresnel and LCD. I will use a filter that blocks UV and IR radiation.
Then goes the fresnel. I still have to find one. Maybe at http://3dlens.com/
Afterwards goes the LCD screen. I plan to strip a 15" monitor.
And finally is the lens. Actually I have no lens yet. I have three single lenses and maybe I will combine them somehow.
Everything will be enclosed in a MDF housing. The inside will be painted in matte black to avoid stray light and therefore diminish blur.
QUESTIONS:
1. First of all, will this work?
2. Should I misplace my lamp? I heard that light reflected from the LCD or filter hits the metal reflector and becomes focused onto the filament, thus heating it too much. Maybe I should misplace the filter a little bit so that it would not reflect directly. But in fact I hope that it will work without all this fuss...
3. Is halogen light OK? The colour temp is a bit low, but I can simply adjust these things on the screen (make it more blue to compensate for the yellow light source). I hope that the light-reflector combo will be powerful enough for my needs. Or maybe I should switch to HID right now? It has a higher colour temp. less heat and more light.
4. What fresnel to choose? Doest the focal length matter? The salad bowl will be sending quite a lot of parallel light anyway... Can you suggest any particular fresnel models and specs.?
5. Is every LCD suitable? People talk about lengthening the ribbons but I guess that it is enough to bend the boards 90* and attach them to the sides of the housing. This can be done on any LCD, am I right? My logic tells me that no LCD on the planet has anything from behind because it has the lights there, so nothing can obstruct the light. I actually haven't seen a single dismantled LCD in my life and for financial reasons my first 'job' on an LCD must be the final and successful one.
6. Will I get a 6x4ft picture out of my setup? I mean a sharp image without significant fallof on the corners and 'watchable' without effort.
7. Are these three lenses that I have of any use? A single lens will project an image but due to different wavelengths I might get chromatic aberration. Due to different distance between lens and middle of LCD and lens and border of LCD I might also get less sharpness on the edges of the image. Am I right? So what to do to avoid it?
Thanks in advance for the replies. I know that the post is boring for the experts but if precise answers are given it might me helpful not only for me. I guess that my setup is basic and most beginners start from a similar point and probably have the same questions.
BIG THANKS
THE POSSIBILITIES:
So first of all my funds are limited to 300$ and I hope to make it within that sum.
I don't have access to additional ribbon cables, controller boards and I haven't even come across a 15" fresnel yet (most are smaller). So my hardware possibilities are basic.
THE NEEDS:
I need a projector that will be used for movies and maybe some browsing/gaming.
The size of the projected image that I want to achieve is around 6 feet on the horizontal side.
Size of the projector housing doesn't matter as I have a big house.
I don't have ambitions to have a bright image even during the day 🙂. Comfortable evening viewing is enough.
THE SETUP:
This is what I have in my mind.
An externally hosted image should be here but it was not working when we last tested it.
My plan is to use a spherical salad bowl 13" or maybe even 15" in diameter. I plan to make it as big as possible in order to cover most of the LCD with light. Other benefits are big difference in size of filament and reflector which gives better sharpness. I guess that such a big reflector will also give better light output as compared to a small one. A big reflector also runs colder because of better heat dissipation.
I plan to use a automotive halogen bulb (100W) as they are compact, very cheap and easy to buy. I don't have access to these specific bulbs you talk about. In the future, if my setup works well, I will switch to a HID (discharge) bulb. I won't have to change basically anything in my setup. Just the bulb mount. This would give me 30% more light when compared to a 100W bulb while only using 35W of power.
The next part is the UV filter. I plan to use photo and film industry products such as www.rosco.com . You can buy all kinds of filters in big sheets. They meet photography standards of course so if you plan to change the tint of the image, just select the right product and expect stable results. They also make their filters in heat proof versions. They have mylar, IR filters etc... So my plan is to block heat from affecting the fresnel and LCD. I will use a filter that blocks UV and IR radiation.
Then goes the fresnel. I still have to find one. Maybe at http://3dlens.com/
Afterwards goes the LCD screen. I plan to strip a 15" monitor.
And finally is the lens. Actually I have no lens yet. I have three single lenses and maybe I will combine them somehow.
Everything will be enclosed in a MDF housing. The inside will be painted in matte black to avoid stray light and therefore diminish blur.
QUESTIONS:
1. First of all, will this work?
2. Should I misplace my lamp? I heard that light reflected from the LCD or filter hits the metal reflector and becomes focused onto the filament, thus heating it too much. Maybe I should misplace the filter a little bit so that it would not reflect directly. But in fact I hope that it will work without all this fuss...
3. Is halogen light OK? The colour temp is a bit low, but I can simply adjust these things on the screen (make it more blue to compensate for the yellow light source). I hope that the light-reflector combo will be powerful enough for my needs. Or maybe I should switch to HID right now? It has a higher colour temp. less heat and more light.
4. What fresnel to choose? Doest the focal length matter? The salad bowl will be sending quite a lot of parallel light anyway... Can you suggest any particular fresnel models and specs.?
5. Is every LCD suitable? People talk about lengthening the ribbons but I guess that it is enough to bend the boards 90* and attach them to the sides of the housing. This can be done on any LCD, am I right? My logic tells me that no LCD on the planet has anything from behind because it has the lights there, so nothing can obstruct the light. I actually haven't seen a single dismantled LCD in my life and for financial reasons my first 'job' on an LCD must be the final and successful one.
6. Will I get a 6x4ft picture out of my setup? I mean a sharp image without significant fallof on the corners and 'watchable' without effort.
7. Are these three lenses that I have of any use? A single lens will project an image but due to different wavelengths I might get chromatic aberration. Due to different distance between lens and middle of LCD and lens and border of LCD I might also get less sharpness on the edges of the image. Am I right? So what to do to avoid it?
Thanks in advance for the replies. I know that the post is boring for the experts but if precise answers are given it might me helpful not only for me. I guess that my setup is basic and most beginners start from a similar point and probably have the same questions.
BIG THANKS
G'day MikePL welcome to the forum mate 🙂
1) Yes it will work
2)Not entirely sure what you mean by "misplace" the lamp
3)Halogen will be hot as you mentioned the colour temp is a little out there, I would purhaps consider more wattage too 100watt aint going to be enough I dont think.
4)fl of the fresnels should match your lens
5)Not every LCD is suitable some have ffc issues check this forum there is a thread on suitable LCDs also i believe there is one hiding on the Lumenlab.com forum somewhere also
6)You will get the image size you want, depending on how you adjust everything and the optics you chose to use it will be watchable etc 🙂
7)You could possibly make a doublet lens from the singlets you have as you suggested the image maybe out on the outer edges using just a singlet. Probably better off buying a good triplet will be worth it in the long run and they aren't very expensive.
As far as the salad bowl for a reflector IMHO dont use it it will cook your LAMP get yourself a Spherical Reflector. Unfortuneatly the norpro bowl is used extensively on the Lumenlab PJ's without mention of the effect it has on lamp life.
Im positive those in the forum that are far more knowledgeable than I will have some input for you bud, in the meantime I hope this has been of some help for you.
Good luck with your projector 🙂
1) Yes it will work
2)Not entirely sure what you mean by "misplace" the lamp
3)Halogen will be hot as you mentioned the colour temp is a little out there, I would purhaps consider more wattage too 100watt aint going to be enough I dont think.
4)fl of the fresnels should match your lens
5)Not every LCD is suitable some have ffc issues check this forum there is a thread on suitable LCDs also i believe there is one hiding on the Lumenlab.com forum somewhere also
6)You will get the image size you want, depending on how you adjust everything and the optics you chose to use it will be watchable etc 🙂
7)You could possibly make a doublet lens from the singlets you have as you suggested the image maybe out on the outer edges using just a singlet. Probably better off buying a good triplet will be worth it in the long run and they aren't very expensive.
As far as the salad bowl for a reflector IMHO dont use it it will cook your LAMP get yourself a Spherical Reflector. Unfortuneatly the norpro bowl is used extensively on the Lumenlab PJ's without mention of the effect it has on lamp life.
Im positive those in the forum that are far more knowledgeable than I will have some input for you bud, in the meantime I hope this has been of some help for you.
Good luck with your projector 🙂
Thanks for the helpful, calming and reassuring info. Good to hear that it will work.
By 'misplacement' I mean to put the bulb slightly out of the focus point so that the returning light doesn't focus on the filament.
Are you sure that my reflector will fry the bulb. Howcome if the bulb has a length of 1,5inches and the salad bowl is 13 or 15 inches, soe there is plenty of room for fresh air. There will be ventilation of course, but I ommitted it because I know how to handle this.
What is FFC? Everyone talks about these ribbon cables, but why are these cables called FFC?
As for the lens, I think that a big diameter will give a brighter image, so if I find the right glass, then I will experiment with it. I guess that with 100W halogen I cannot put a tiny lens.
By 'misplacement' I mean to put the bulb slightly out of the focus point so that the returning light doesn't focus on the filament.
Are you sure that my reflector will fry the bulb. Howcome if the bulb has a length of 1,5inches and the salad bowl is 13 or 15 inches, soe there is plenty of room for fresh air. There will be ventilation of course, but I ommitted it because I know how to handle this.
What is FFC? Everyone talks about these ribbon cables, but why are these cables called FFC?
As for the lens, I think that a big diameter will give a brighter image, so if I find the right glass, then I will experiment with it. I guess that with 100W halogen I cannot put a tiny lens.
If you are going to use a 100 watt car bulb, spend a few extra dollars and get the Sylvania Silverstar H3 65watt fog lamp bulb it has the correct colortemp 4000K and a few more lumens than a standard halogen (1310 lux). If you want to get even more tricky on the designing the reflector you could try the 9005 SilverStar Headlight Bulb (1700 lux 4000K). However on a 15" set up you are not gonna get much light out of it.
Regardless of which halogen you use you will also need an IR filter or the likelyhood of burning up the LCD is high.
I am testing the headlight bulb on a ps one/crt projector I have built, which is alot more efficient in how it uses light. I am working on a power supply for the bulb now.
If you search around and do alot reading you will find many people have tried using halogens and they get mediocre results on small format projectors and very poor results on the large format projectors, and almost always end up upgrading to a Metal Halide.
I am no expert by any means, but I hope this helps a little. 🙂
Regardless of which halogen you use you will also need an IR filter or the likelyhood of burning up the LCD is high.
I am testing the headlight bulb on a ps one/crt projector I have built, which is alot more efficient in how it uses light. I am working on a power supply for the bulb now.
If you search around and do alot reading you will find many people have tried using halogens and they get mediocre results on small format projectors and very poor results on the large format projectors, and almost always end up upgrading to a Metal Halide.
I am no expert by any means, but I hope this helps a little. 🙂
This is why I am trying to use a 100W bulb as minimum. A standard 65W delivers around 1300lux while the 100W will give more. But eventually switching to HID will five me around 3000 lux. I am optimistic and think that something can be done with halogen or HID bulbs. Besides, I dont feel happy about my setup draqgging 400 or 500W of power almost on a daily basis.
I gues that if I make a big reflector, then I will be able to deliver beter light
I gues that if I make a big reflector, then I will be able to deliver beter light
Just so you know a 300watt halogen floodlight gives you about 6000 lumens. A 175watt halide gives you around 10,000 lumens and runs cooler than the halogen by far. I tried the halogen and it just isn't worth it in the end you'r only going to save about $40 after you add the extra fans and you'll have low light output. Just MO though.
Clinton
Clinton
the problem with me lies not in the price but the availability. I guess that the 175W option is nice, but where to get these bulbs? Can you give any models that I can plug to 240V? Any models of bulbs made by Philips, GE, Osram, Hella.. These are companies which are for sure available in Poland, so I can go to a rep. and order them.
a possible source
You might want to try:
http://www.exclusiv-online.com/shop/index.php?main=product&art=LGSETMH&lang=en&up=0
Thay have pretty much everything you need, priced in Euros and powered by 240 Volt 50 Hz.
You might want to try:
http://www.exclusiv-online.com/shop/index.php?main=product&art=LGSETMH&lang=en&up=0
Thay have pretty much everything you need, priced in Euros and powered by 240 Volt 50 Hz.
Your large diameter lenses
You might be able to use those lenses. Take them outside at noon with a meter stick or tape measure, and focus the smallest image you can form of the sun on the ground. Then measure the distance from the center of the lens to the ground. That is the focal length of the lens. Write it down!
If you have a lens with a focal length of 200 mm or less, then you might be able to use it as a light condensor. This captures a lot of the light from the lamp and bends it toward the LCD.
If you have a lens with a focal length of 240 to 600 mm, then you might be able to use it as a projection lens. Not as good as a triplet, but the price is right!
If you have a pair of lenses with identical focal lengths around 500 to 1000 mm, then you could use them to make a symmetrical duplet lens by putting one curved-side-out at each end of a 15 cm tube. The combined focal length will be around half the focal length of each lens.
You might be able to use those lenses. Take them outside at noon with a meter stick or tape measure, and focus the smallest image you can form of the sun on the ground. Then measure the distance from the center of the lens to the ground. That is the focal length of the lens. Write it down!
If you have a lens with a focal length of 200 mm or less, then you might be able to use it as a light condensor. This captures a lot of the light from the lamp and bends it toward the LCD.
If you have a lens with a focal length of 240 to 600 mm, then you might be able to use it as a projection lens. Not as good as a triplet, but the price is right!
If you have a pair of lenses with identical focal lengths around 500 to 1000 mm, then you could use them to make a symmetrical duplet lens by putting one curved-side-out at each end of a 15 cm tube. The combined focal length will be around half the focal length of each lens.
your design
1) Your UV filter, fresnel, and LCD can all be right against each other. I don't think you get anything by spacing them apart.
2) A spherical reflector makes a very bad parabolic reflector. Used this way, it will just get a spot in the center that is lit by the reflector. So it will make your image very unevenly lit. Either use a real parabola shaped reflector, or put the bulb at the center of curvature of the spherical reflector and use a lower fresnel to turn the diverging cone of light into a parallel beam. The second option will work a lot better.
3) If you use a halogen bulb, instead of MH, you will need MORE power to get the same results. So using a 100 Watt halogen is a bad idea. You might as well just buy a big fresnel to tape onto a cardboard box to put over your TV! See if you can find a 250 Watt 240 Volt halogen bulb that runs directly off your power mains. These should be very easy to find. Then you won't have to find a power supply. While you are out looking, also find a great big fan for it!
Or better yet, get a MH bulb and ballast. Osram has lots of european distributors. Find one of them and get a double-ended 150 to 400 Watt MH bulb with a color temperature of 4200 to 6500, and a CRI or 85 or higher. Then get a ballast for it that runs from your 240 volt power.
1) Your UV filter, fresnel, and LCD can all be right against each other. I don't think you get anything by spacing them apart.
2) A spherical reflector makes a very bad parabolic reflector. Used this way, it will just get a spot in the center that is lit by the reflector. So it will make your image very unevenly lit. Either use a real parabola shaped reflector, or put the bulb at the center of curvature of the spherical reflector and use a lower fresnel to turn the diverging cone of light into a parallel beam. The second option will work a lot better.
3) If you use a halogen bulb, instead of MH, you will need MORE power to get the same results. So using a 100 Watt halogen is a bad idea. You might as well just buy a big fresnel to tape onto a cardboard box to put over your TV! See if you can find a 250 Watt 240 Volt halogen bulb that runs directly off your power mains. These should be very easy to find. Then you won't have to find a power supply. While you are out looking, also find a great big fan for it!
Or better yet, get a MH bulb and ballast. Osram has lots of european distributors. Find one of them and get a double-ended 150 to 400 Watt MH bulb with a color temperature of 4200 to 6500, and a CRI or 85 or higher. Then get a ballast for it that runs from your 240 volt power.
haha don't hold back there Guy tell it how is lol...cardboard box over your tv lol classic. I still dont see why people attempt to go with halogen for the sake of a few dollars... if its that big a finacial strain save for another week or two and get the MH in the long run you will save money and have much much better results. As Guy rightly points out you will need more power to get same results, and then you have the joy of trying to cool this big "heater" you have enclosed in a lil metal box! Im sorry, but I just dont get it fellas...
Thanks for the replies. I will definitely change the bulb for the proper one. Osram indeed has distributors in Europe because it is a German company 😉
Guy Grotke,
1. I plan to space the 'filter-fresnel-LCD' apart to get better air circulation. The air is supposed to enter around the sides of the LCD and exit in the back, behind the lamp or above it.
2. I will have to rethink the reflector issues. I have many options to work on, so I will give a try to anything that comes to my mind.
3. I wanted to start with the halogen for the sake of seeing if my project works at all, not because I am fussy about cash
. I have also two or three projector halogen bulbs (150W, 300W and 500W) but I don't consider any of them due to heat issues. So they just sit and wait to be used for something else. I will buy a MH bulb but I think that the single-ended is better because it has a smaller 'gas filament'. Am I right?
What is CRI of 85 or higher?
As far as lenses are concerned, I have one 150mm another 200mm. They might be used for projection. I took them off some photo equipment, so they are multicoated and have a 2,5in diameter so they are bright. Made by Schneider, so also pricey 😱 Expect good quality out of them...
Another question... I noticed that some people use TWO fresnels on both sides of LCD. I thought that one would be enough...
Thanks for help once again.
Guy Grotke,
1. I plan to space the 'filter-fresnel-LCD' apart to get better air circulation. The air is supposed to enter around the sides of the LCD and exit in the back, behind the lamp or above it.
2. I will have to rethink the reflector issues. I have many options to work on, so I will give a try to anything that comes to my mind.
3. I wanted to start with the halogen for the sake of seeing if my project works at all, not because I am fussy about cash
. I have also two or three projector halogen bulbs (150W, 300W and 500W) but I don't consider any of them due to heat issues. So they just sit and wait to be used for something else. I will buy a MH bulb but I think that the single-ended is better because it has a smaller 'gas filament'. Am I right?What is CRI of 85 or higher?
As far as lenses are concerned, I have one 150mm another 200mm. They might be used for projection. I took them off some photo equipment, so they are multicoated and have a 2,5in diameter so they are bright. Made by Schneider, so also pricey 😱 Expect good quality out of them...
Another question... I noticed that some people use TWO fresnels on both sides of LCD. I thought that one would be enough...
Thanks for help once again.
Ah, and if you could check osram.com for me, please.
Their product range is huge and I don't know which lamp will be suitable. They have a range from 37W to 12,000W (1,150,000 lumens, can you believe it?)
Thanx
Their product range is huge and I don't know which lamp will be suitable. They have a range from 37W to 12,000W (1,150,000 lumens, can you believe it?)
Thanx
Osram bulb
From looking at:
http://www.osram.com/pdf/service_corner/hqi_programm.pdf
I would recommend the Powerstar HQI-TS 250/D part number 4050300 436050.
This is a double-ended 250 Watt bulb with an Fc2 base (connector at each end). It has a CRI > 90, a color temp of 5100 K, 9000 hour life, 20000 lumens output. The outer glass tube is only 25 mm diameter, so you can use a small reflector and condensor lens.
From looking at:
http://www.osram.com/pdf/service_corner/hqi_programm.pdf
I would recommend the Powerstar HQI-TS 250/D part number 4050300 436050.
This is a double-ended 250 Watt bulb with an Fc2 base (connector at each end). It has a CRI > 90, a color temp of 5100 K, 9000 hour life, 20000 lumens output. The outer glass tube is only 25 mm diameter, so you can use a small reflector and condensor lens.
CRI
This is Color Rendering Index. It is a measurement of how well a particular lamp makes colors appear. Sunlight on a clear day has a CRI of 100. Low pressure sodium lights have a CRI of 0, so all the colors are way off.
Most metal halide lamps have a color temperature of 3000 or 4200 and a CRI of 65. Good MH lamps for LCD projection have color temps of 5000-5500 and CRIs of 85-95.
I think your lenses are too strong for use as projection lenses with a large LCD panel. A shorter focal length lens gives you more magnification, so you get a wider image from a shorter throw distance. You would need a focal length greater than 500 mm, or the field angle will be too wide for a simple lens. Most of the people using 325 mm fl lenses are buying triplets, so they get a wide field angle.
But those would make good condensor lenses, if you can keep them cool enough.
This is Color Rendering Index. It is a measurement of how well a particular lamp makes colors appear. Sunlight on a clear day has a CRI of 100. Low pressure sodium lights have a CRI of 0, so all the colors are way off.
Most metal halide lamps have a color temperature of 3000 or 4200 and a CRI of 65. Good MH lamps for LCD projection have color temps of 5000-5500 and CRIs of 85-95.
I think your lenses are too strong for use as projection lenses with a large LCD panel. A shorter focal length lens gives you more magnification, so you get a wider image from a shorter throw distance. You would need a focal length greater than 500 mm, or the field angle will be too wide for a simple lens. Most of the people using 325 mm fl lenses are buying triplets, so they get a wide field angle.
But those would make good condensor lenses, if you can keep them cool enough.
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