Guide 1: - Building A Fresnel Projector
(Taken from www.DIYProjection.tk)

What you will need:

Now get your TV, (a 14inch model is fine)

and measure the size of the actual screen

Now cut out 4 pieces of cardboard out, two 45 cm long and the width of your TV screen, and two 45 cm long and the height of your TV

Then cut out a piece of card board the same size as your TV screen, find the centre and cut out a circle 17cm in diameter (about the size of an old 7inch vynal single! [bit smaller])

To find the center of the card (to help with getting the circle in the right plan, draw a line from each of the diagonal sides of the card. This way youll find the exact center

You will now have 5 pieces of cardboard, as below

Paint these all matt black, then leave to dry. When they have dried, take the piece that is the same size as your TV screen, and attach the fresnel lens to it with tape, (try to centre it.) You can cut the lens down to size, or can leave it so you can make changes to your unit later.

Make sure you tape the lens securely in place as above, becuase any movement will make the picture blurry and impossible to focus. Now assemble the 4 45 cm pieces of cardboard to make a box, secure with duct tape.

Be sure to use plenty of duct tape inside and out as you dont want any light to escape (please also note that you should have painted you box black by now!)

Then tape this to the front of your TV, be sure to use more duct tape to cover any gaps, so that light only shines thru the box, and none escapes around the edges.

Now attach some duct tape to the sides of the lens screen (so you can pull it back and forth when its in the box)and slide the lens and cardboard into the box on the front of your TV.

Once it is attached to your tv it should look some thing like this

Now turn your tv upside down, (make sure its been turned off for 12 hour before this, else the screen may temporaily turn green or purple) and turn on you TV, turn off all the lights and draw the curtains.
You have to turn your TV upside down, as the magnifying lens inverts the image.

Start with the lens board about halfway into your TV box, and place your TV about 2inches away from a white wall, screen or white sheet.

You should get a picture on the screen, now move back until the picture gets bigger.
Stop at what feels like a good distance, and now adjust the lens board until you get a clear picture.
If you cant get a clear picture, try turning your lens board with your fresnel lens the other way around. You should have the smooth side facing the screen, but sometimes the ridged side works better. Once you've found where the best point for your lens to be it, cut off any remaining card board.
The more time and care you take making your projectotr and fine tuneing the image by correctly focusing it, the better your picture will be. You can just slap one of these together, but youl be disapointed (tho you will get an image) so please work hard at it, and if you have and problems, first read the FAQ (frequently asked questions) then email me at help@bigscreentv.20m.com

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