I have just bought a 3M 9700 OHP (which hasn't been delivered yet) so Im not sure if it comes with a flip-in magnifier. The trouble is that even if it does the 1.3X magnification won't give me a big enough screen size in my little bedroom, so Im thinking of trying a generic magnifying glass wth either 3X or 5X magnification. Will this work - I realize the image quality wil suffer but Im willing to accept that for greater size and having had a crappy CRT/fresnel lens set up for the past year, the image will still be fantastic by comparison.
So will the 3X/5X magnifier work, or is the flip-in magnifier used with an OHP a special kind of magnifying lens?
Thanks
So will the 3X/5X magnifier work, or is the flip-in magnifier used with an OHP a special kind of magnifying lens?
Thanks
try it first
Overhead projectors usually give you a very large size image from a short distance. You may not need any magnification at all. Keep in mind that the bigger you make the image, the less light per square centimeter. As the diagonal size doubles, the brightness goes down by a factor of 4!
Try working on some stuff to block light leakage from the OHP. That will really help your image.
Overhead projectors usually give you a very large size image from a short distance. You may not need any magnification at all. Keep in mind that the bigger you make the image, the less light per square centimeter. As the diagonal size doubles, the brightness goes down by a factor of 4!
Try working on some stuff to block light leakage from the OHP. That will really help your image.
I just bought one too
I'm not so sure about the size factor with ohps, unless you pull them back , the size isn't apt to change. I bought a 9700 with no magnifier, and have a 10 x 12 room. As far as the new person I talked to this morning, and I'll call back to talk to someone else, they don't even carry that accessory anymore, a company called KMR electronics was referred and they said they only carry the machines, not the accessories. Can you make a magnfier for the 9700 out of a fresnel lense or something
I'm not so sure about the size factor with ohps, unless you pull them back , the size isn't apt to change. I bought a 9700 with no magnifier, and have a 10 x 12 room. As far as the new person I talked to this morning, and I'll call back to talk to someone else, they don't even carry that accessory anymore, a company called KMR electronics was referred and they said they only carry the machines, not the accessories. Can you make a magnfier for the 9700 out of a fresnel lense or something
try it first!
OHPs usually have a focal length around 300 mm, so you get a big image from pretty close up. Try putting your LCD (or a transparency of the same size) on the OHP, with the throw distance you plan to use. The image size may be fine without trying to shorten the lens focal length. Putting the projector at the back of the room is a GOOD thing!
Remember, the bigger you make the image, the dimmer it gets. And it does that by the square of the diagonal image size.
OHPs usually have a focal length around 300 mm, so you get a big image from pretty close up. Try putting your LCD (or a transparency of the same size) on the OHP, with the throw distance you plan to use. The image size may be fine without trying to shorten the lens focal length. Putting the projector at the back of the room is a GOOD thing!
Remember, the bigger you make the image, the dimmer it gets. And it does that by the square of the diagonal image size.
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