what makes a lens "macro"?

[jackfrost]

ok, n00b time.

when I was searching for a zoom lens, it seemed that some of them had a macro switch on it, and others did not. the one i got (Tamron 75-300) does not, but it still has "Macro" in parenthesis after the name.

is macro capability just the ability of the lens to focus real close to something while zoomed in real far?

 

[Digital Matt]

is macro capability just the ability of the lens to focus real close to something while zoomed in real far?

Basically.

A true macro lens will focus down to 1:1, which means the subject is "lifesize" on a 35mm negative. In reality, alot of so-called macro lenses will only focus to 1:2, which is half life size, but in essence you got it. They let you focus closer than normal lenses.

 

[Soocom1]

I am going to add a little to what Digital Matt said:

The purpose of the macro as he said is to bring the image up to a 1:1 ratio or larger on the negative/image sensor.

The term Macro lens is defined by Merriam-Webster as:

Main Entry: macro lens
Function: noun
Etymology: macr-, from the fact that the focal length is greater than normal
: a camera lens designed to focus at very short distances with up to life-size magnification of the image
Google has this point on the word macro:

Macro photography is the term used to describe photography taken with great magnification. It doesn't necessarily mean that the subject is at very close range to the camera, just that the magnification ratio is 1:1 or higher.

Translation, is that the image captured is actually life sized or larger than the object photographed. Macro lenses are also popular (although very expensive) with nature photographers shooting wildlife from a distance. It gives off great detail while allowing a zooming on the subject.
Macros are also used in Portrait and product photography for the same reason; extremely fine detail.

This link will help understand at least one of their uses. It about insects and such, but is very helpful.

http://www.marietta.edu/~mcshaffd/macro/macro.html

 

[neverhappen]

Another thing is the focus distance. Most lenses cannot focus as close as a macro lens can.

Definitions above though are better than mine, but hope this additional "bit" of detail helps too.


-----------------
neverhappen.com