Hi everyone,
This site seems quite informative but still couldn't find what I am looking for, I really hope you guys can help me.
I am actually trying to achieve the exact opposite of what most people try to do with their DIY projector builds. I am trying to make a "small image" projector.
I have tried using all kinds of combinations of focal calculations but cant seem to get the result that I am looking for. I will be honest with you, I am very new to this and still acquainting myself with it.
I want to build a projector that can project an image as small as 10mm across to as large as about 50mm - 70mm across without loss of image clarity. I also want to be able to project the image from a short distance, up to maybe 300mm away. I will use a 7" LCD (1280x800) and want to be able to build this projector no larger than an A4 size sheet of paper.
is this achievable? if so, how would I go about building it? would you be able to give me any advice, ideas? Do you sell any products to make this work?
Any ideas welcome as my head is about to explode
Cheers
Jon
This site seems quite informative but still couldn't find what I am looking for, I really hope you guys can help me.
I am actually trying to achieve the exact opposite of what most people try to do with their DIY projector builds. I am trying to make a "small image" projector.
I have tried using all kinds of combinations of focal calculations but cant seem to get the result that I am looking for. I will be honest with you, I am very new to this and still acquainting myself with it.
I want to build a projector that can project an image as small as 10mm across to as large as about 50mm - 70mm across without loss of image clarity. I also want to be able to project the image from a short distance, up to maybe 300mm away. I will use a 7" LCD (1280x800) and want to be able to build this projector no larger than an A4 size sheet of paper.
is this achievable? if so, how would I go about building it? would you be able to give me any advice, ideas? Do you sell any products to make this work?
Any ideas welcome as my head is about to explode
Cheers
Jon
May be a bit late but for what it's worth here I go...
you can certainly achieve what you want to, using a 7" LCD. the thing to note here is that if you want to get from 10mm to 70mm diagonal projection image from 300mm away then you'll be limited in the type of projection lens you can get.
After some quick calculations with a 285mm focal length lens, 300mm away from the screen, with the 7" screen you'd get 10mm diagonal image. To get 70mm diagonal image with the same lens you'd need to move the lens back to be 390mm away from the screen.
Of course you can change the lens focal length to whatever you want your sweet spot to be. i.e. a 220mm focal length lens gives you a 70mm diagonal image at 300mm away from the screen and you'd need to get closer to something like 230mm from the projection screen.
Have a search online for the Lumenlab focalcalc or go here for a nice online projection image calculator
ALLINBOX
As to the image quality I have no idea what compressing an image that much would do to it and in terms of brightness again wouldn't be able to help you much there. All I would say is that your light source should be as close to a pinpoint source as possible with this size of image.
you can certainly achieve what you want to, using a 7" LCD. the thing to note here is that if you want to get from 10mm to 70mm diagonal projection image from 300mm away then you'll be limited in the type of projection lens you can get.
After some quick calculations with a 285mm focal length lens, 300mm away from the screen, with the 7" screen you'd get 10mm diagonal image. To get 70mm diagonal image with the same lens you'd need to move the lens back to be 390mm away from the screen.
Of course you can change the lens focal length to whatever you want your sweet spot to be. i.e. a 220mm focal length lens gives you a 70mm diagonal image at 300mm away from the screen and you'd need to get closer to something like 230mm from the projection screen.
Have a search online for the Lumenlab focalcalc or go here for a nice online projection image calculator
ALLINBOX
As to the image quality I have no idea what compressing an image that much would do to it and in terms of brightness again wouldn't be able to help you much there. All I would say is that your light source should be as close to a pinpoint source as possible with this size of image.
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