www.diycinema.co.uk

[Dust2Dust]

Hi, here are some pics of my work in progress, hope you get some ideas from them.





I used two strips of lexan to seperate the circuit boards and unsoldered one of the large connectors and ribboned it up so i could fit them into a smaller space.
How far in from the edge of the OHP is the fresnel, (lighted area?) on an average OHP? so that i give enough room so all the LCD is on OHP?
Thanks, now all i have to do is work out how to attach the two pieces!
D2D

[Dust2Dust]

Here are some pics of my panel working, no overhead projector yet, hopefully next week for that. Pictures rotated threw 90 degrees, to show right way up.




My VGA Box for inputting digital tv, video etc.

How i wired my power supply as described by Doug, and tested by me on working monitor! Dont worry about the other two wires, not needed.


D2D
P.S. doing some work for local primary school computer room, might be able to aquire an OHP there for services rendered! ( extra! got an OHP from ebay, too small a stage area, so swapped it for a broken one from local school, fixed it and am well happy!)
D2D

Last edited by Dust2Dust on Sun Apr 16, 2006 1:34 pm; edited 2 times in total

[doug]

Thats look great! Thanks for your post. I like the way you've extended the black connector so you can fold the boards over. I'm not sure about the OHP dimensions as I'm not using one. If you can get a cheap projector with good optics it might be worth converting it to a metal halide setup, or just get a 400w OHP like Greg on this forum! Good luck with the rest fo the build, although looks liek you're almost finished!

[Dust2Dust]

Bought an ohp from ebay, an elite viewwrite ii, dont bother with this ohp, it has a very small fresnel lens area, so you can only get 3/5ths of your screen projected, no good.
Was able to swap it for a faulty focusing proper ohp from my local primary school which was easily fixed and had a larger screen area.
Let this be a warning to diy projector makers, not all ohp's are created equal!
Waiting for more powerful bulbs, as only got 150 watt bulb in it so far, gives a reasonably bright picture, but could be better, a bit dark at the top and bottom.
Doug, can you alter the hight of the picture in the 1510 menus? could'nt find hight, only width adjustment.
When i get the new bulbs, (only 250 watts, but should do the job) will post pictures of the results.
D2D

[doug]

HI D2D, great work so far, i'm not sure about vertical adjustment, i too haven't found anything. There is a program called powerstrip which can do what you wish from windows if that would help. I think there is a free shareware version, just search google for it.

Have you seen my post about gaining access to the service menu? There are lots of interesting things but be careful as it's easy to mess things up..

I've reset the power on hours count so I know how much use my bulbs had...

For your OHP i have seen small arc halogen bulbs which run off mains voltage (no need to uprate the transformer) up to about 1kw for less than £20, that could give you some incredible brightness but cooling would need to be good!

[Dust2Dust]

Sorry for the delay, here is a picture of my projector in action.
It has been changed a lot since this picture was taken, it is clearer, but still the same size, as can go no bigger than the screen i have at the minute.
Still have some things to put right\investigate, before i commit myself to going the whole way and making a stand alone projector, like affording the lighting, have a good cylinder type fan, salvaged from an old overhead, shifts some air, but makes very little noise, like the fans in blow heaters, i think. works exactly the same, and blow heaters make less noise than normal PC type fans, and they are designed for hot\hot air.
I digress, have a habit of going far off the point, ah well, heres an out of date picture of my projector in operation!

D2D

Last edited by Dust2Dust on Sat Dec 31, 2005 3:01 pm; edited 1 time in total

[doug]

Great work!

Looks like you've got a nice big OHP and haven't lost much of the corners...looks bright too..

Those cylinder (cross flow?) fans are great - i originally planned on getting one for my build but couldn't find them cheap anywhere..good find

I ended up with a 15W Delta fan (80mm) which even after building into a silencing box is still pretty loud..

A never ending job but worth it....

[Dust2Dust]

Hi, here is two pics from Madagasgar, the first is full picture, which measures in at 70 inches, widescreen, which is as big as i can go as i have no bigger screen, (4/3 is bigger though)
the second is close-up so you can see the individual pixels.


Am having some problems with light affecting the top of my screen, nearly inverting dark scenes.
Have improved the image by making a metal cover, to shield the base of the bulb from transmitting it's light to the fresnell, as i have come to the conclusion that the bottom of the bulb magnifies the light due to the glass where the power pins come out of glowing, and the curve of the actual bulb itself.
Made some difference for me.
D2D
Mark
P.S. these pictures where taken before the light shield was fitted.
Will post others showing the difference, you can just see the lighter patch on the full screen picture.

PPS, have come to the conclusion that it is all down to the way that an OHP fresnel lens works, bending the light so as to direct it towards the lens, making the angle at the top of the screen where the light goes through the LCD too steep, causing the polarizer to invert/cancel out the light at the top of the screen. going to split my fresnel too see if this has any effect on overall even-ness? of light spread.

D2D
Mark

Last edited by Dust2Dust on Sat Apr 01, 2006 2:14 pm; edited 1 time in total

[Dust2Dust]

Hi, Here is a picture of my LCD ready for putting onto my OHP.
It makes it so much safer, less likely to break, when mounted like this.

Still in the development stages though.
D2D
Mark

[doug]

Great work there D2D, i'm sure that'll come in handy if you decide to build one from scratch with custom lenses too...

[Dust2Dust]

Here is the specs of my VGA box, some of the options must only be applicable to NTSC version.


D2D