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Fresnel diy



 
 
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  #1  
Old February 12th 05, 12:13 PM
.::SuperBLUE::.
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Default Fresnel diy

Is it possible to make fresnel lenses at home?
I am thinking of some kind of some kind of hard, transparent photopolymers
and then?

How are fresnel lenses made at all?

How are glass lenses made at all?

What is the simplest or best way to make something like that?

Or if it is too hard, where can cheaply I buy large fresnels and other
lenses?


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  #2  
Old February 12th 05, 12:53 PM
Ian Stirling
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In sci.optics .::SuperBLUE::. wrote:
Is it possible to make fresnel lenses at home?

Yes.

I am thinking of some kind of some kind of hard, transparent photopolymers
and then?


Photopolymers don't really help much.

How are fresnel lenses made at all?


I've made a negative lens from epoxy.
Sprayed a PVC lens with a light oil.
Run thin epoxy across it.
Peel off.
The basic idea is to take an imaginary thick lens.
Now, slice it into 1mm (or so) thick cylinders.
Then knock it on a table so that all the edges touch the table.
Then cut off the rest at 2mm above the table.

How are glass lenses made at all?


Google for
lens grinding pitch


What is the simplest or best way to make something like that?

Or if it is too hard, where can cheaply I buy large fresnels and other
lenses?


http://www.3dlens.com/
May be of use.
  #3  
Old February 12th 05, 06:13 PM
dadiOH
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..::SuperBLUE::. wrote:
Is it possible to make fresnel lenses at home?


Forget it.

Or if it is too hard, where can cheaply I buy large fresnels and other
lenses?


Check Edmund Scientific.

--
dadiOH
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  #4  
Old February 12th 05, 07:24 PM
Martin Brown
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..::SuperBLUE::. wrote:

Is it possible to make fresnel lenses at home?
I am thinking of some kind of some kind of hard, transparent photopolymers
and then?

How are fresnel lenses made at all?

How are glass lenses made at all?

What is the simplest or best way to make something like that?

Or if it is too hard, where can cheaply I buy large fresnels and other
lenses?


Scavenge one from a junked overhead projector.

You would probably have very slightly more luck spin casting a mirror.

Regards,
Martin Brown
  #5  
Old February 13th 05, 08:01 AM
zeitgeist
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what are you trying to do with it?

I know some photographers that use those full sheet magnifyers that older
people buy in the drug store, its like 8x11, put them on their off camera
flash to prevent lens flare.


Is it possible to make fresnel lenses at home?
I am thinking of some kind of some kind of hard, transparent photopolymers
and then?

How are fresnel lenses made at all?

How are glass lenses made at all?

What is the simplest or best way to make something like that?

Or if it is too hard, where can cheaply I buy large fresnels and other
lenses?




  #6  
Old February 13th 05, 09:15 PM
.::SuperBLUE::.
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It is not for that,...
I am trying to make a few things

1. An optical system (that includes large Fresnel lens?) that projects crt
image (tv or monitor) onto a wall. I think that large format lenses are used
in 50 or 60 inches projection TV,
but how can i get them cheap? And where?
2. An OHP projector that includes Fresnel lens that projects lcd monitor
image onto a wall.
found on www.tomshardware.com (not a priority) the first one will be made
from a 15" to 19" max. lcd monitor. the second is going to be a high
resolution one or multi projector configuration or both.

3. A fast "super telephoto" lens for a digital slr camera. It will be a
manual focus lens at least 600mm f/4 made from various lenses from who knows
where, and some of the lenses will be made by myself (i hope). I have the
optalix-lt program demo for 16 days now http://www.optenso.de . There is an
example of a 600mm f/4 Nikkor Nikon lens

4. A system for burning offset plates, (maybe also a a plate enlarger, repro
camera, ...?)
5. A large format camera 8*10 inch ( I have found schemes)

6. who knows what else - I have more time than money
I had some education about optics, but if you know where to find informaton,
programs or something useful about optics,
please let me know to remind myself. Nowdays, I mostly experiment with the
basics and write down some ideas that are too expensive for me to make right
now. I am starting up a graphical firm with a low budget. The will to make
things by myself is my greatest capital. I also have friends, people and
industries nearby who can help me out. Also there is the internet,
usenet,...


  #7  
Old February 14th 05, 03:12 PM
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You will not get very good imagery using Fresnel lenses. In imaging
systems Fresnel lenses are almost exclusively used as field lenses to
project the system pupil, not for imaging. This is how they are used
in overhead projectors.

 




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