Hey all,
So I have looked around here for the last hours or so - and plan on continuing my research when I am no longer at work...But in the mean time I was wondering if I could get a few quick answers.
From the limited time I have had to look at some of the DIY projector threads...it looks like building a unit is not gonna be all that difficult. I am by no means a rocket scientist - but I think that I will have little problem putting one of these together. What I was concerned with is the following:
1. If I were to use the 7" 'widescreen' TFT monitor that I currently have in my truck, what sort of isuues would I have with picture cropping? From the looks of most of the designs - the LCD screen is placed very close the the lens - and I'm concerned that part of the picture will be cut-off.
2. What sort of problems should I expect in regards to cooling? Should I be worried that the heat from the lamp(s) will damage the TFT/LCD screen - even if a low heat bulb is used?
3. I have checked-out a few of the links that are provided in other threads - and did not not see anything with a 'step-by-step' procedure for this project. Do any such procedures exist?
As stated above, I will be doing more research on this Forum...and hope to begin my projector project after the holidays...So any input you guys (and girls) can offer is greatly appreciated.
Thanks in advance.
Jumpman
So I have looked around here for the last hours or so - and plan on continuing my research when I am no longer at work...But in the mean time I was wondering if I could get a few quick answers.
From the limited time I have had to look at some of the DIY projector threads...it looks like building a unit is not gonna be all that difficult. I am by no means a rocket scientist - but I think that I will have little problem putting one of these together. What I was concerned with is the following:
1. If I were to use the 7" 'widescreen' TFT monitor that I currently have in my truck, what sort of isuues would I have with picture cropping? From the looks of most of the designs - the LCD screen is placed very close the the lens - and I'm concerned that part of the picture will be cut-off.
2. What sort of problems should I expect in regards to cooling? Should I be worried that the heat from the lamp(s) will damage the TFT/LCD screen - even if a low heat bulb is used?
3. I have checked-out a few of the links that are provided in other threads - and did not not see anything with a 'step-by-step' procedure for this project. Do any such procedures exist?
As stated above, I will be doing more research on this Forum...and hope to begin my projector project after the holidays...So any input you guys (and girls) can offer is greatly appreciated.
Thanks in advance.
Jumpman
Whats up. I'm pretty new here too but I can answer some of you questions.
1. There are two common ways of making a projector. One is to use a projector lens and the same size panel mounted directly behind it. In your case, as long as you got a lens that was as wide as your screen, then it would work. The other method is to use a fresnel next to the panel while having the projection lens a good distance in front of it (just like an overhead projector). Keep in mind however that those widescreen panels from portable and car DVD players have a terrible horizontal resolution. They look great on a 7" screen, but projected on a large screen will look like crap. IMO, getting a high res 3:4 panel and hooking it up to a computer is a much better solution. If you want true widescreen, you could either change the vertical size of the display, project it at an angle, or make an anamorphic lens (there's a nice thread on that). Make sure you figure out the specs of your panel before you commit to anything.
2. I don't have first hand experience, but cooling is usally needed. Fans are good enough to get the job done. A lot of it will depend on how far the screen is from the lightsource. If you get the specs to your panel, you can find out the operating temperatures. Then all you need is a thermometer. There are also special glass panels (I forget what they're called) that absorb heat while allowing light to pass through. There's also "cold mirrors" that absorb heat but reflect all the light. An LCD absorbs 85-90% of the light that passes through it, so you need a very powerful light source. 3500 lumens is pretty much the bare minimum. 7 or 8k is generally good enough. From what I've gathered here, Metal Halide bulbs are the only way to go. They are available at a high enough wattage and will put out the correct color temperature- with much less heat than other types of bulbs w/ the same wattage. Halogens have a yellowish tint and they're way too hot. MH lamps are expensive at first because you need to buy a ballast, but replacing the bulbs is pretty reasonable.
3. There are links to people's projects. I haven't found any step by step ones, but the one's I've found provide good info. I know it's very difficult to search for specific info here because the two main forums contain thousands of posts. Because of that, there have been tons of people asking the same questions over and over again, while people are reluctant to answer because it's been discussed before. Kinnda sucks. The FAQs are have some good info.
1. There are two common ways of making a projector. One is to use a projector lens and the same size panel mounted directly behind it. In your case, as long as you got a lens that was as wide as your screen, then it would work. The other method is to use a fresnel next to the panel while having the projection lens a good distance in front of it (just like an overhead projector). Keep in mind however that those widescreen panels from portable and car DVD players have a terrible horizontal resolution. They look great on a 7" screen, but projected on a large screen will look like crap. IMO, getting a high res 3:4 panel and hooking it up to a computer is a much better solution. If you want true widescreen, you could either change the vertical size of the display, project it at an angle, or make an anamorphic lens (there's a nice thread on that). Make sure you figure out the specs of your panel before you commit to anything.
2. I don't have first hand experience, but cooling is usally needed. Fans are good enough to get the job done. A lot of it will depend on how far the screen is from the lightsource. If you get the specs to your panel, you can find out the operating temperatures. Then all you need is a thermometer. There are also special glass panels (I forget what they're called) that absorb heat while allowing light to pass through. There's also "cold mirrors" that absorb heat but reflect all the light. An LCD absorbs 85-90% of the light that passes through it, so you need a very powerful light source. 3500 lumens is pretty much the bare minimum. 7 or 8k is generally good enough. From what I've gathered here, Metal Halide bulbs are the only way to go. They are available at a high enough wattage and will put out the correct color temperature- with much less heat than other types of bulbs w/ the same wattage. Halogens have a yellowish tint and they're way too hot. MH lamps are expensive at first because you need to buy a ballast, but replacing the bulbs is pretty reasonable.
3. There are links to people's projects. I haven't found any step by step ones, but the one's I've found provide good info. I know it's very difficult to search for specific info here because the two main forums contain thousands of posts. Because of that, there have been tons of people asking the same questions over and over again, while people are reluctant to answer because it's been discussed before. Kinnda sucks. The FAQs are have some good info.
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