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Does a lens exist

imported_Snagle

Golden Member
Sep 28, 2004
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Originally posted by: C6FT7
Human eyes do a superb job at this.

Why doesn't the camera?


Look at the light switch on the wall. Now put your finger in front of your face; is it in focus? Nope.
 

Rubycon

Madame President
Aug 10, 2005
17,768
485
126
Originally posted by: Snagle

Look at the light switch on the wall. Now put your finger in front of your face; is it in focus? Nope.

Umm yes it is - perfectly clear. I'd take a picture but ummm nevermind. :p

 

mercanucaribe

Banned
Oct 20, 2004
9,763
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Originally posted by: C6FT7
Originally posted by: Snagle

Look at the light switch on the wall. Now put your finger in front of your face; is it in focus? Nope.

Umm yes it is - perfectly clear. I'd take a picture but ummm nevermind. :p

That's physically impossible.
 

imported_Snagle

Golden Member
Sep 28, 2004
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Originally posted by: C6FT7
Originally posted by: Snagle

Look at the light switch on the wall. Now put your finger in front of your face; is it in focus? Nope.

Umm yes it is - perfectly clear. I'd take a picture but ummm nevermind. :p


yeah, it's clear if you focus on it, but then the light switch will be out of focus.

It is impossible for the eye to have 1 object 6 inches from it in focus while retaining focus on something 10 feet away.
 

Rubycon

Madame President
Aug 10, 2005
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Originally posted by: mercanucaribe

That's physically impossible.

Well there has to be an explanation.

Originally posted by: Snagle

yeah, it's clear if you focus on it, but then the light switch will be out of focus.

It is impossible for the eye to have 1 object 6 inches from it in focus while retaining focus on something 10 feet away.

6 inches? Why so far away? Now a screen will be tricky but that is probably some kind of illusion. I can watch things through a screen without too much interference but if something is moving perpendicular to the screen elements it will flicker badly like a borked de-interlacer. Moire is present sometimes as well.

Moving back a few inches off the screen improves things dramatically. An insect on the screen (hopefully on the outside!) is in clear focus as is things 20 meters past the screen. I did not think this was abnormal. Now if a picture is taken one has to choose what to focus on. I believe if everyone's eyes worked like (the camera) they would go crazy in short order!
 

bsobel

Moderator Emeritus<br>Elite Member
Dec 9, 2001
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Originally posted by: C6FT7
Human eyes do a superb job at this.

Why doesn't the camera?

Did you mean to say 'keep the background in focus'?
 

MillionaireNextDoor

Platinum Member
Nov 16, 2000
2,918
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A friend's friend in Stanford has such a lens. Cost him $10k to build it with his technique. No one else makes them as far as I know.
 

clamum

Lifer
Feb 13, 2003
26,256
406
126
You can alter the depth of field on a camera so it is very small (one thing or part of it in focus, the rest is blurry) or large so the whole picture from close up to far away is in focus.
 

imported_Snagle

Golden Member
Sep 28, 2004
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Originally posted by: MillionaireNextDoor
A friend's friend in Stanford has such a lens. Cost him $10k to build it with his technique. No one else makes them as far as I know.

Huh? I can set any of my lenses to F14 and get everything in the frame in focus.
 

DurocShark

Lifer
Apr 18, 2001
15,708
5
56
Originally posted by: MillionaireNextDoor
A friend's friend in Stanford has such a lens. Cost him $10k to build it with his technique. No one else makes them as far as I know.

Shens

Optics are a well understood science. The only "new" technology was the ability to create aspherical class thanks to computers. But all those really do is correct chromatic aberrations and distortion.
 

imported_Snagle

Golden Member
Sep 28, 2004
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Originally posted by: DurocShark
Originally posted by: MillionaireNextDoor
A friend's friend in Stanford has such a lens. Cost him $10k to build it with his technique. No one else makes them as far as I know.

Shens

Optics are a well understood science. The only "new" technology was the ability to create aspherical class thanks to computers. But all those really do is correct chromatic aberrations and distortion.

Yup. Canon pours millions in to R&D each year, there isn't much they don't know about how lgiht works and interacts with glass ;)
 

DurocShark

Lifer
Apr 18, 2001
15,708
5
56
Originally posted by: aiex
Just use a really small appeture >f/10 and that should work for you...


F/10 is not a small aperture.

f/22 or higher. I have a lens for an 8x10 camera that goes to f/64. :)
 

DigDug

Guest
Mar 21, 2002
3,143
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Yuck. Depth of field is what makes things so interesting. Point and shoots always use infinity focus. That's pictures from those things are so damn boring.