DIY Video Projector Part II

[slize]

hi mgerny,

your 2nd design is very interesting. but let me ask u some questions:

- why TWO 300W lamps (each of it has more than 300 degrees celcius, try to handle one first), ONE glas won't help for the heat problem... i have three glases before the lcd comes... and it still has 40 degrees celcius after 4 hours... (which is ok, i think)

- second problem of the two lamps is you will have to hotspots in the projected image. u are right if u want to light out the ankles but don't forget the middle of the picture... hotspots are seen becaus one point is brighter than the other...

- are u using two reflectors? what do u think about my theorie in my previous post?

- and how will your fans be positioned

sorry for my bad english hope you got the idea of what i wanted to ask...

best regards andy

[mgerny]

I planned on installing one large high volume fan with a baffle to keep the noise levels down, And just venting the sides of the box to force a convection within the chamberto keep the heat as even as possible. One of the other fan positions is on the top of the box, and vents on the bottom. All I am trying to do is keep the temp down in the box, and still looking for a glass that will absorb the unwantes heat froom the light. I have heard that some of the hear (IR) is reflected back into the lighted area anyway, because the LCD's only use about half of the light unless they are designed to be a clear view like the larger LCD panels used in overhead projection projection systems.
The LOA lights will have the manufac glass still on them. I planned on keeping them as factory as possible, but not sure about the life of the lamp or the plastic case it comes in if the temps get too hot.

I have another design with the LOA lights facing each other 90 deg from the lcd with mirrors in a v to reflect the light towards the lcd. I think this might be a more efficient way to light the perimiter without loosing the light in the center.

[mgerny]

The first mirror and the lens are part of the light module, These will not be removed for the first test. I might get out the hacksaw if it doesnt work, and start major modifications. I think I can keep it small or maybee make it smaller. It all depends on how much of this I want to make custom, and how much I want to keep the parts in sets, so they are easily swapable. If the lamp goes out, I dont want to take apart the entire box to get to a lamp. With the light module and the sleve that it goes into I can jest slide it out of the back and replace the lamp or the whole module.

Not to mention there is a light module that has two lamps installed that has more output in the same size module.

Future upgrade possibities, or just looking into the option for a day/night switch that would be easily turned on and off.

I am banking on the first design, or something close to it as my goal the second design is one to fall back on, just in case.

Keep the input coming.

[tahustvedt]

How come noone has tried using anamorphic lenses in their DIY projectors? It would enable you to take advantage of the full vertical resolution of the LCD-panel with widescreen material and give a much smoother picture because the picture compressed vertically.

It's very easy to make an anamorphic lens, just read the thread in this forum and visit my website. It can be made in any size, but when used it a hot area it should have an expansion chamber for the fluids.

I would make one if I was to make a projector.

Here's a picture of one I made earlier:


And here it is hanging in front of my old projector:





Tor Arne

[slize]

thanks a lot arne,

this is what i always looked for... not only will it better for the resolution but also for the impression of brightness of the projected picture...

i will start immediately to built such a thing...

best regards
andy

[Undream]

HEY GUYS!!!! WHATS UP.


/me makes cameo appearance

[slize]

i looked the emperors new groove this weekend on my projector at 100". It was awesome

but then i wanted to look password swordfish; and i was disapointed

the picture is seeable though but not bright enough, i think its too dark. so i decided to take the 500W halogen bulb. but i wasn't really better. 300W -> 6500 lumens 500W -> 9500 lumens

i finally decided to buy an hqi bulb at 400W (i think this is comparable to an mh bulb) costs 65$ a bulb

it has 30000 lumens 5600K colour temperature and lives 8000h. I asked in every electric store i knew; nothing came out. but guess where i found it: in a aqarium store. it is a fish lamp for aquriums; i was really surprised...

all in all with electrical stuff it costs 115$

i've gone this far now i won't stop just because of the bulb. it is my last inverstation i hope...

will post pictures with the new lamp, didn't get the didi cam yet

cy' all andy

[slize]

hi undream,

you are still not satisfied with your 400W mh bulb with 36000 lumens???

you scare me, because i've invested 115$ in the same thing too and now you are tellin gme it won't work??? All the nice money...

or is just that you are not satisfied with it? Please I need hope...

best regards andy

[verbose mustafa]

It all depends what size picture you are shooting for and what you want for brighness. 36000 = 360 ansi lumens (picture brighness on wall). Very good for a 5-6 foot image. Hell, i was impressed projecting using the lcds backlight as a lightsource.

[Undream]

I sold my whole 400W setup for $75, and I sent out $120 about 4-5 months ago to a guy for a 1000W setup, and, he never delivered. I got ripped, and, it basically put my project on hold since I will prolly never be able to come up with the $120-150 again.


I've invested well over $450 into this project, and, basically, all I have is a nice screen on my wall and a Sharp QA-1750. Doh.