magnifiyng glass for project.lens?

[moi]

this link give a simple example about projection by using a magnifying glass
can we use it (one or two or more) to build a good projection lens?
or it'll distort the image,
http://www.phys.ufl.edu/~deserio/simplens/simplens.htm

bye and thanx for your replies

 

[NITEMARE]

i don't think that normal magnifiers can do anything for us. i disassembled a big triplet projektion lense setup. there are 2 bi convex lenses wich are more curved on one side, the other side is more flat but still curved a little bit. in the middle of those two there is a lense that makes things look smaller (sorry but i don't know the word for the opposite of magnify). it's bi concav and a little bit smaller than the other two. here a pic of my experimental setup. i can move the lenses to try and zoom. but atm my main issue lies between the light and the fresnels...

An externally hosted image should be here but it was not working when we last tested it.

 

[mathias]

No it´s not a good idear using magnifying glass. I have tried it, you can not focus the edge with it. You must use that type of glass that you can find in reading-eyeglasses, but bigger.

 

[machs_fuel]

i'm using a single type lense, and i find the image is accceptable, but there certainly is some blur at the edges or the center depending of you focus things. i'm planning on a triplet for revison 2.

if your going a pro set-up go with the triplet, but if this is a budget experiment (like mine) that your working on a single should do.

 

[moi]

hi

thanx for your answers
i've found 3 leica lenses 50mm diam
they are curve only on one side the other side is curved in the same way
like magnifying eyeglasses
the fl is 0,5meter and +2 dioptr

i'll try them

bye and thanx

 

[verbose mustafa]

If you look an a siglet projection lens (at least on the ai-1000), it is sort concave on one side and convex on the other. This sort of fixes that problem or blurryness.

 

[Ehuwiko]

I have an Elmo projector with a single lens, and there is no blur whatsoever, anywhere.

 

[NITEMARE]

it looks like a single lense but actualy there are two lenses. most projectors have just a simple projection lense, which looks to be just one but it's a combination of two. the guy at the optics shop told me that. he ran some tests and found out. then he presented me a lense, which has the same stats like my projection lense (dioptrin, focal length...) but he said, that it probably wouldn't have the same effekt. look at both sides and if you have one sine curved more and the other side curved less, you got one like mine...