Hello!!!
I very pleased to be in such an innovative community, but as any new guy i will like help big time.
First let me explain my project:
I have a budget of 500 Euros or about 650$( for optics , tft and light).
I want to create an lcd projector with a 17 inch tft monitor.
The design of the box will be mine( im experienced with wood & metal)
But i want some help about optics.(any help or redirection to some other thread or website is welcome).
The lcd screen will be a 12ms 1280X1024 panel.
Here are my questions:
1) What contrast is acceptable for solid black in a medium lit room?
2)Is there any other factor that helps for solid black that i need to have in mind when ill buy the tft monitor?
3)Are there any tft monitors that i sould avoid because of very difficult disassembly?
4)What metal halide lamp is the best for great performance (ansi lumens) and superior color temp?(price please).
5)Can i chance the distance from the projection screen without the picture getting blurry?Can it be done by moving the projection lenses.
6)Is there i particular type of mirror that i need to select to avoid the ghost image that is projected too?
7)1 UV filter and 1 IR filter are enough for the protection of the tft panel and the fresnel lens (I plan to install 2 fans for the cooling of the fresnel).
8)My projector will be about 14 feet away from the screen.What projection lens i ll need for a 100-150 inch screen sixe?
9) I would like a complete list of the optics (and their fls and sizes) that ill need.
10)What will be the final ansi lumens of a project like this?
11)Any suggestion and expertize opinion is welcome.
Thank you in advance!!!!
Theo
I very pleased to be in such an innovative community, but as any new guy i will like help big time.
First let me explain my project:
I have a budget of 500 Euros or about 650$( for optics , tft and light).
I want to create an lcd projector with a 17 inch tft monitor.
The design of the box will be mine( im experienced with wood & metal)
But i want some help about optics.(any help or redirection to some other thread or website is welcome).
The lcd screen will be a 12ms 1280X1024 panel.
Here are my questions:
1) What contrast is acceptable for solid black in a medium lit room?
2)Is there any other factor that helps for solid black that i need to have in mind when ill buy the tft monitor?
3)Are there any tft monitors that i sould avoid because of very difficult disassembly?
4)What metal halide lamp is the best for great performance (ansi lumens) and superior color temp?(price please).
5)Can i chance the distance from the projection screen without the picture getting blurry?Can it be done by moving the projection lenses.
6)Is there i particular type of mirror that i need to select to avoid the ghost image that is projected too?
7)1 UV filter and 1 IR filter are enough for the protection of the tft panel and the fresnel lens (I plan to install 2 fans for the cooling of the fresnel).
8)My projector will be about 14 feet away from the screen.What projection lens i ll need for a 100-150 inch screen sixe?
9) I would like a complete list of the optics (and their fls and sizes) that ill need.
10)What will be the final ansi lumens of a project like this?
11)Any suggestion and expertize opinion is welcome.
Thank you in advance!!!!
Theo
LCD, not projector1) A contrast ratio of 300:1 or above is adequate
3) A good tip is to look at what monitors other people are using.
4) 400W will be enough for most people, if the room is dark, 250W works just fine. The 400W will generate a lot more heat than the 250W, so it might be easier to use the 250W, and not as expensive to that. The minimum color temp is somewhere around 4000K I think. Most lamps people use is around 4200K, the maximum is perhaps somewhere up around 6500K.
5) The distance to the projection screen is not fixed. If you move the projector backwards, the projected image will get larger, but you need to adjust the projection lens to get a focused image.
6) I'm not sure what ghost image you are talking about, perhaps the screen door effect. You don't need to use any mirrors if you don't want to.
7) On IR and UV filter is usuallly enough. Place as many fans as you need to keep the LCD below 32 degrees C. Large ones doesn't generate as much noise as smaller ones.
8) Make sure the projection lens that you buy can fit a whole 17" LCD monitor.
3) A good tip is to look at what monitors other people are using.
4) 400W will be enough for most people, if the room is dark, 250W works just fine. The 400W will generate a lot more heat than the 250W, so it might be easier to use the 250W, and not as expensive to that. The minimum color temp is somewhere around 4000K I think. Most lamps people use is around 4200K, the maximum is perhaps somewhere up around 6500K.
5) The distance to the projection screen is not fixed. If you move the projector backwards, the projected image will get larger, but you need to adjust the projection lens to get a focused image.
6) I'm not sure what ghost image you are talking about, perhaps the screen door effect. You don't need to use any mirrors if you don't want to.
7) On IR and UV filter is usuallly enough. Place as many fans as you need to keep the LCD below 32 degrees C. Large ones doesn't generate as much noise as smaller ones.
8) Make sure the projection lens that you buy can fit a whole 17" LCD monitor.
Lentroo said:
I assume he is referring to the slight doubling of the image that is apparently produced by using a mirror that has silvering (i.e. reflective material) behind the glass rather than on the front (I say apparently because I too am a complete newbie, but I have learnt this from reading about it). In answer to the question - I don't believe the effect is great, but for optimal image quality you should seek out a front-silvered mirror. A science store would probably sell them as they are used in telescope optics and soforth. That is, of course, if your design requires a mirror.
suggestions
Mirrors: It depends on what you are looking at. If you have white letters on a black background, then you can see very distinct ghost images an inch or two above the letters. You will also see a lot of image fogging on the sides. These will look very bad on graphic images or using your projector as a computer monitor. But if you only look at movies, then you might not notice it. All of that goes away with a first surface mirror. It will improve your black areas quite a bit. Or make a straight-through design with no mirror.
Why don't you go with:
http://www.exclusiv-online.com/
Their equipment looks pretty good, and they are in the EU. Since you want big screen images, go for the 400 Watt lamp!
Moving the projector around: If you change the throw distance a lot, then you would be wise to make the spacing adjustable between the lamp arc (or condensor lens) and the condensor fresnel. By "a lot", I mean going from 10 feet to 20 feet. You need to get the condensed image of the lamp arc focussed into your projection lens. When you move the projection lens to focus the screen image at different distances, you might get more light if you can also adjust the condensor system a few centimeters.
17" LCD with 14' throw = 100 inch image with 620 mm fl lens
17" LCD with 14' throw = 150 inch image with 434 mm fl lens
lumenlab.com has a 450-500 mm fl triplet (144 to 128" image)
diybuildergroup.com has a 451 mm fl triplet (144" image)
get big fresnels from lumenlab: You will need their long focal length field fresnel for this projector.
Mirrors: It depends on what you are looking at. If you have white letters on a black background, then you can see very distinct ghost images an inch or two above the letters. You will also see a lot of image fogging on the sides. These will look very bad on graphic images or using your projector as a computer monitor. But if you only look at movies, then you might not notice it. All of that goes away with a first surface mirror. It will improve your black areas quite a bit. Or make a straight-through design with no mirror.
Why don't you go with:
http://www.exclusiv-online.com/
Their equipment looks pretty good, and they are in the EU. Since you want big screen images, go for the 400 Watt lamp!
Moving the projector around: If you change the throw distance a lot, then you would be wise to make the spacing adjustable between the lamp arc (or condensor lens) and the condensor fresnel. By "a lot", I mean going from 10 feet to 20 feet. You need to get the condensed image of the lamp arc focussed into your projection lens. When you move the projection lens to focus the screen image at different distances, you might get more light if you can also adjust the condensor system a few centimeters.
17" LCD with 14' throw = 100 inch image with 620 mm fl lens
17" LCD with 14' throw = 150 inch image with 434 mm fl lens
lumenlab.com has a 450-500 mm fl triplet (144 to 128" image)
diybuildergroup.com has a 451 mm fl triplet (144" image)
get big fresnels from lumenlab: You will need their long focal length field fresnel for this projector.
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