MURA coded aperture / manufacturing / producing pictures

Mustafa Umut Sarac · Dec 10, 2007

I want to learn the final quality of mura coded aperture lenses compared with pinhole .

And of course manufacturing and deciphering at the computer.

Has anyone have experience ?

My math/physics education not able to understand papers on it .

Best ,

Mustafa Umut Sarac

Ole · Dec 10, 2007

Since it requires decoding by computer (deconvolution), it falls rather far outside the scope of APUG.

It might possibly give results equivalent to a zero-thickness ideal lens, but the depth of field should still be a function of the numerical aperture - which in such a system will be twice the physical aperture.

walter23 · Dec 10, 2007

Maybe some ambitious individual could come up with a decoding optic that would attach to an enlarger somewhere, thus obviating the need for computational deconvolution. You seem pretty ambitious, Mustafa. Why not give it a go?

I'll stick with pinholes and glass lenses

Mustafa Umut Sarac · Dec 10, 2007

Decoding with an enlarger ! its a interesting idea and could be covered by APUG also.

Do I need to cipher and decipher with the same mura or how can this be done ?

Ole · Dec 10, 2007

I think you would need to place the MURA in precisely the same place relative to the recording medium, with a tolerance somewhat less than the wavelength of the light. That means you might have a remote chance with glass plates, but film is definitely out!

Mustafa Umut Sarac · Dec 10, 2007

I think an enlarger mura bed moves with an stepper motor or micrometer can be helpful.

Its not cheap but its not very expensive also.

They make quantum computer experiments with micrometers on breadboards or rails.

I always dreamed to use this stuff at my camera but chance is for enlarger.
www.newport.com have extensive equipment for this. some times they lower some products and you can buy without a bite.

I m still try to keep to subject in analog but everybody have computers at home and use this stuff.
Problem is finding software for this.
And other problem is to know whether you are closing to the alignment or you are opening the gap with micrometer.
I think a method needed.
Can I see a less corrected image when adjusting or do I need to be perfect for to see the result ?

Mustafa Umut Sarac

Ole · Dec 11, 2007

Mustafa Umut Sarac said:
...
Can I see a less corrected image when adjusting or do I need to be perfect for to see the result ?...

I don't know, but I believe the sequence will be something like this:

nothing - bad - worse - bad - worse - perfect - worse - bad - worse - bad - nothing.

And that that whole sequence will occur when moving the MURA about 4 times the wavelength of light, or 2 micrometer. Also being a quarter wavelength off will give pretty bad results, for a reasonably sharp image the position will have to be precise to better than 1/8 wavelength!

Analog deconvolution is an interesting concept, and this may well be one of those cases where it works faster and better than a digital solution!

Mustafa Umut Sarac · Dec 11, 2007

Can anyone suggest a computer program for design and for decoding ? I think analog way is extremelly hard ?

freygr · Dec 12, 2007

There are times where analog will always be faster and easier to do than using a computer, and optics is just one of those things. Now if the only tools you had was self programing super computers that changes things.

MURA coded aperture / manufacturing / producing pictures

Mustafa Umut Sarac

Ole

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walter23

Mustafa Umut Sarac

Ole

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Mustafa Umut Sarac

Ole

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Mustafa Umut Sarac

freygr

MURA coded aperture / manufacturing / producing pictures

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