Floating Optical System: what is it?

[ajperk]

Hello everyone,

I've noticed that several lenses, especially macro lenses, are said to possess "floating optical systems" in their design. I have read before that this is related in some way to maintaining the lenses optical quality over the entire range from minimum focusing distance to infinity, but I am unclear what exactly such a design is. How does a floating optical system differ from a non-floating optical system? And how does such a design improve the optical quality over the focus range of the lens? Can anyone explain this to me, or point me in the right direction to finding out?

Thanks in advance!

 

[Drizzt321]

Yes please!

Paging Dr Neuro. Dr Neuro, please report to the forum.

 

[neuroanatomist]

You rang?

http://www.canon.com/camera-museum/tech/room/flo.html

 

[ajperk]

Quite informative and succinct. Thank you!

 

[Drizzt321]

Ah, perfect. Just an optical element(s) that doesn't move directly with the focusing group. Makes sense! Thanks Neuro! ;D