Building your own projection tv

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Originally Posted by GepperRankins

how much better does splitting the fresnal make the picture quality?

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The collimating (or condenser) fresnel makes the light from the bulb run parallel through the LCD. You do not need this fresnel IF you are using a parabolic reflector. However, keep in mind that the light hitting the parabolic reflector will be parallel but the light from the bulb will be spirical. The collector (or field) fresnel is the opposite, which bends light towards a point. Both fresnels will affect the amount of light coming through as well as sharpness especially the collector fresnel. You can adjust image sharpness by trying different distances between the LCD and the collector fresnel.

so should i split mine and put half in front of the LCD?

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Originally Posted by GepperRankins

so should i split mine and put half in front of the LCD?

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No, if you're using a regular projector setup. Moving the fresnel will change the focal length to the projection lens, which might make more problems. Yes if you're building your own box.

well i've built my own box. i've got a feeling splitting the fresnal will get rid of darker edges and make the picture sharper, am i right?

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Originally Posted by GepperRankins

well i've built my own box. i've got a feeling splitting the fresnal will get rid of darker edges and make the picture sharper, am i right?

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Dark corners are usually due to problems with the reflector/bulb setup such as reflector size/type, bulb to reflector distance, etc.

So how many of you finally joined LL or paid for an account? :lol:

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Originally Posted by tracydani

So how many of you finally joined LL or paid for an account? :lol:

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not me :snooty:

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Originally Posted by tracydani

So how many of you finally joined LL or paid for an account? :lol:

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Guilty :blushing:

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Originally Posted by Darth Sushi

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Originally Posted by GepperRankins

well i've built my own box. i've got a feeling splitting the fresnal will get rid of darker edges and make the picture sharper, am i right?

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Dark corners are usually due to problems with the reflector/bulb setup such as reflector size/type, bulb to reflector distance, etc.

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i was just trying to split it now but couldn't so i tried putting it in front instead of behind and it looks a lot better :blink:

i thought the dark areas could be caused because with 1 full fresnal on only one side, the light is forced through the edges of the LCD at an angle. imagine yourself looking at an LCD from and angle, less light gets through :unsure:

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Originally Posted by GepperRankins

i thought the dark areas could be caused because with 1 full fresnal on only one side, the light is forced through the edges of the LCD at an angle. imagine yourself looking at an LCD from and angle, less light gets through :unsure:

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That's possible too. Fresnels usually just change the direction of light. But if the light hitting the fresnel already has dark corners, then dark corners will also be projected.

I thought the purpose of the fresnel between the light and the lcd was to distribute the light more evenly and straight ahead instead of at an angle?

And the dark edges has to do with not enough point source light hitting the lcd? Do you have a reflector? Maybe try playing with the distance of the light from the first fresnel so more sourcepoint light hits it?

I just confused myself again :lol:

So how much in pounds has it cost to build these projecters

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Originally Posted by GepperRankins

how much better does splitting the fresnal make the picture quality?

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Splitting it doesnt improve the quality, its the quality is actually bettter when they are together, but when they are split apart u can do keystoning

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In short:

Unsplit fresnels produce a better image, as there's no distortion effect between the LCD and hte projection lens.

Split fresnels allow you to use the field lens to do keystone adjustment.

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@gripper 550.00 CAD
Canada Dollars = 253.919 GBP
United Kingdom Pounds

hopefully i dont go over :01: :lol:

we should try building this:
http://engadget.com/entry/1234000217057824/
http://www.digitimes.com/NewsShow/20...s/image002.jpg

about £20 i think

well i got my lcd last week...but it turned out to be completely opposite of what the seller wrote on ebay...it was a whopping 30MS and 400:1 contrast ratio and it wasnt in anyway widescreen :lol:

so i sold it for $165 (bought for $155)

and i just bought this:
http://www.newegg.com/Product/Produc...82E16824024509
from ebay...
http://cgi.ebay.com/ws/eBayISAPI.dll...DME:B:AAQ:US:1 (i told the guy i didnt want to wait for the bidding to end so i made him a offer and he accepted :) )
paid $175CAD including shipping for the poly view monitor

now this monitor has AMAZING specs:
500:1 Contrast ratio
16ms

i just hope it comes soon!

i envy. that is very nice. should perform great.

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Originally Posted by ApacNTS

i envy. that is very nice. should perform great.

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yea i some ppl say that the contrast ratio is even higher than 500:1 :o!

well the shipping could take a month :(

how long do u think its going to take to get from Washington(state) to Toronto...

pretty far..

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Originally Posted by Spicker

how long do u think its going to take to get from Washington(state) to Toronto...
pretty far..

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It all depends on the weather. If the roads get boggy, the mules will have problems making any sort of speed. A month could really be a conservitive estimate. Especially if it is snowing in the hills.....

Hope it works out fine for you when you get it :)

gah lcd came in today...charged me 22$CAD in customs...gona go pick it up tomorrow.. :(

i bought a ballast from ebay...on sunday...and after doing some research it might be a ICE CAP which costs $305CAD and i paid $120USD shipped.

the reason i didnt buy from LL is because alot of ppl seem to be having problems with LL e-ballasts.

Hey guys!
just wanted to let you all know that i finally finished my projector and the results are jaw dropping!

http://img476.imageshack.us/img476/3462/100_1187.th.jpg http://img476.imageshack.us/img476/407/100_1189.th.jpg http://img476.imageshack.us/img476/6489/100_1188.th.jpg http://img476.imageshack.us/img476/5875/100_1190.th.jpg http://img476.imageshack.us/img476/3762/100_1191.th.jpg http://img476.imageshack.us/img476/1989/100_1193.th.jpg http://img476.imageshack.us/img476/8150/100_1192.th.jpg http://img476.imageshack.us/img476/6512/100_1194.th.jpg
link if u cant see the images:
http://img476.imageshack.us/gal.php?g=100_1187.jpg

and btw the images are projected on a PINK wall and...i dont have a reflector in there...after painting the wall and adding a parabolic reflector the brightness is literally going to double.

but even without all that the quality is qutie stunning!

EDIT:
as for the projected screen size is from 70"100+" depends on what im doing...

i prefer having it at 70" when watchin movies as the sofa is quite close to the wall....

Well, done! I just got my pro-lens so it will be a couple of months away for me.

wow that looks sick. but you know you have to get a fifth element shot so it's official :P

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Originally Posted by ApacNTS

wow that looks sick. but you know you have to get a fifth element shot so it's official :P

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/me goes to newnova.org :)

man i want to make one, but i gotta learn....

Hey Spicker, those are great results:)

I got sidetracked and moved back to the states so haven't done anything yet other then gather a couple of small parts:blushing:

As soon as I get set back up financialy etc. I will get on it again.

Any others have some pics?

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Originally Posted by tracydani3

Hey Spicker, those are great results:)

I got sidetracked and moved back to the states so haven't done anything yet other then gather a couple of small parts:blushing:

As soon as I get set back up financialy etc. I will get on it again.

Any others have some pics?

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After prolong procrastination, I just started mine (under arctan): http://www.lumenlab.com/forums/index...howtopic=13531

I hope to be up and running in two weeks.

That's looking really good Darth:)

How long has it taken you to do what you have so far? Once you actualy began that is:P

I still haven't decided what type I want. I am leaning toward vertical, but tall like a pillar or something. I geusss it depends on when I begin and if I still live where I am now.

I like the idea of having my couch and love seat set up at a 90 degree angle and have the pillar set between them aiming to the center of in front of both.

Let me know how the pro lens comes out too:)

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Originally Posted by tracydani3

That's looking really good Darth:)

How long has it taken you to do what you have so far? Once you actualy began that is:P

I still haven't decided what type I want. I am leaning toward vertical, but tall like a pillar or something. I geusss it depends on when I begin and if I still live where I am now.

I like the idea of having my couch and love seat set up at a 90 degree angle and have the pillar set between them aiming to the center of in front of both.

Let me know how the pro lens comes out too:)

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Well, I spent about 4 months trying different designs on paper. I just did not like the length of a straight path design. So far, it's been about 3 weeks into this build. I know... I'm a slow builder. I give an update upon mounting the LCD.

woot. getting back to colder weather so i'll set mine up again. gonna make it work better this year. maybe split the fresnal and set up a curtain so i can get the whole screen in perfect focus :01: