What is breathing ??

[igmolinav]

Hi,

What is breathing ... ??

I got the following definition from Wikipedia:

Breathing refers to when a lens' optics change the apparent focal length slightly when shifting the mechanical focus. Some (often more expensive) lenses are designed to lessen the degree this effect. Lens breathing does not prevent one from racking focus or following focus with this lens, but it lessens the desirability of any type of focus adjustment, since it noticeably changes the perspective and composition of the shot.

Would you please tell me a bit more. Suppose you have a 50 mm. lens and then you change the focus distance. How does (the) breathing (of the lens) come into play ??

Thank you, kind regards,

igmolinav.

 

[dmoon]

I think this refers primarily to zoom lenses where if you change focus the zoom changes a bit.

-dmoon

 

[igmolinav]

Hi,

Thank you : ) !!!

So, it happens only with zoom lenses.

I´ll try to post in a couple of hours the link to a 10´minute video
in which the sales rep of Zeiss in the USA talks a bit about
breathing, (towards the end of the video). I´ll post it later on
tonight.

Thank you again, kind regards,

igmolinav.

 

[KeithPratt]

So, it happens only with zoom lenses.

No, it happens with primes too. Here's a Canon 50mm f/1.4 breathing.

Without knowing this for a fact, I'd assume that when a lens manufacturer claims their lens does not breathe, it technically does, just imperceptibly.

 

[igmolinav]

Hi,

This is the video:
http://www.freshdv.com/2010/04/freshdv-nab-2010-zeis.html

Very kind regards,

igmolinav.