Dumb questions.. why lenes are round but the sensor and pictures are rectangle?

[astroNikon]

Cause then you'd have round photos!

and we all know, that round photos could roll away.
:mrgreen:

 

[480sparky]

Cause then you'd have round photos!

and we all know, that round photos could roll away.
:mrgreen:

Actually, it's so people don't mistake round photos for coasters.


And since no one has mentioned it: Sometimes, during the design and manufacture of a lens, it's easier and/or cheaper to have an element or group rotate as part of the focus and/or zoom operation as opposed to merely moving it along the optical axis.

 

[timor]

Cause then you'd have round photos!

He he... Wouldn't be that perfect ? NO MORE PROBLEMS WITH FRAMING !! VERTICAL OR HORIZONTAL - JUST ONE CAMERA GRIP ! ( No good for camera makers ?) No problems with editing, portrait ? here you go ! landscape ? no problem ! Everything in one file. But that would be too perfect ! The truth is sensor is too expensive to put in one camera too much of it. The second thing is limitation of camera makers imagination. They still, despite all this new technology, mentally are stuck in old standards and push them on us. There is no reason for square sensors, actually that stupid to still have them.

 

[Judobreaker]

Cause then you'd have round photos!

He he... Wouldn't be that perfect ? NO MORE PROBLEMS WITH FRAMING !! VERTICAL OR HORIZONTAL - JUST ONE CAMERA GRIP ! ( No good for camera makers ?) No problems with editing, portrait ? here you go ! landscape ? no problem ! Everything in one file. But that would be too perfect ! The truth is sensor is too expensive to put in one camera too much of it. The second thing is limitation of camera makers imagination. They still, despite all this new technology, mentally are stuck in old standards and push them on us. There is no reason for square sensors, actually that stupid to still have them.

Not exactly...
Round sensors would make things slightly more complicated on nearly all fronts, and they would also be more expensive.

First off, digital images are rectangle, whether you like it or not. All round photo's are simply square images with the photo in is and a lot of empty space around it.
You can't easily make a round image (I won't say it's impossible, but it's a whole lot more complicated) so it's only logical to think in rectangle images.
The fact that digital images are rectangles will also make it so a lot of people will always crop their images to rectangles. Why make round images when most people will crop to rectangle anyway?

Second, the sensor would be much, much larger! Say you wanted to create a round sensor that would enable you to crop to the same size as a D800 sensor... It would be 1.7 times as large!
That would make the sensor much more expensive!
Besides, where the heck are you then going to put that sensor? You'd need to make the camera bodies a whole lot bigger to put that sensor in there.

I think that rectangle sensors simply make cameras less complicated and a lot cheaper.
I know I wouldn't want to spend a few hundred bucks more for a much larger camera with a round sensor which I'm going to crop to rectangle anyway... I'll just stick to rotating for portraits.

 

[chuasam]

Aspherical Lenses aren't round...they're well, Aspherical.

 

[KmH]

Round lenses are a lot easier and cost effective to make.

An aspherical lens is still round. but has surface profiles that are biconvex and not part of sphere or a cylinder.
http://en.wikipedia.org/wiki/Aspherical_lens