What is CPU? in terms of photographic terms....


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zoossh

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Nov 29, 2005
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keep seeing this word, esp on lens. searching this word on google, only derives results for the computer CPU, and surprisingly a search in clubsnap using "CPU" as the key word derives no results.....

anyone can advise?
 

Seeing the word where?
 

[FONT=Verdana, Arial, Helvetica, sans-serif]"...These have a "CPU" built into the lens, but this really is just a fancy way of saying it has an electronic transfer of basic lens information to the camera...."
http://www.bythom.com/lensacronyms.htm

I suspect that the lens CPU is nothing more than a computer chip that gives the camera body information regarding the lens etc. That's what I think. I may be wrong. :think:
[/FONT]
 

'Corrective Photography Unit'... has a complex hi-tech chip in there which analyzes the scene and immediately gives electrical shocks to the photographer if the composition is lousy... ;)
 

Hobbesyeo said:
[FONT=Verdana, Arial, Helvetica, sans-serif]"...These have a "CPU" built into the lens, but this really is just a fancy way of saying it has an electronic transfer of basic lens information to the camera...."
http://www.bythom.com/lensacronyms.htm

I suspect that the lens CPU is nothing more than a computer chip that gives the camera body information regarding the lens etc. That's what I think. I may be wrong. :think:
[/FONT]

yah you are correct. That's what those electronic contacts on your lens are for... relaying of information. It will tell the camera what's the distance your lens is focused at, the aperture, the focal length, etc.
 

which means that most exif info is from the lens and not from the body, right?
 

zoossh said:
which means that most exif info is from the lens and not from the body, right?
No. It's from the body. The lens info is used by the body for exposure control and was there since film days where 'EXIF' is not even heard of yet. But, yes, a portion of the EXIF info pertaining to the lens such as the max aperture, min aperture, focal length, AF etc are actually provided by the lens to the body which generates the EXIF.
 

lsisaxon said:
No. It's from the body. The lens info is used by the body for exposure control and was there since film days where 'EXIF' is not even heard of yet. But, yes, a portion of the EXIF info pertaining to the lens such as the max aperture, min aperture, focal length, AF etc are actually provided by the lens to the body which generates the EXIF.

what i mean is if i use a non-electronic lens on a digital body, i.e. zenitar fisheye lens 16mm f/2.8 on a nikon D50, if the lens doesn't tell the body what is the aperture size when the aperture ring is turned, would the body be able to generate the exif info on the aperture size used?
 

zoossh said:
what i mean is if i use a non-electronic lens on a digital body, i.e. zenitar fisheye lens 16mm f/2.8 on a nikon D50, if the lens doesn't tell the body what is the aperture size when the aperture ring is turned, would the body be able to generate the exif info on the aperture size used?

No. On my camera it just generates f1 as the aperture.
 

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