Macro lens magnification ratio

No.

Magnification is a function of focal length and focusing distance. A macro lens allows greater magnifications becuse it can be focused to shorter distances than a non-macro lens.

sorry i was not very clear,

i'm not asking whether a macro lens's magnification at infinity end is bigger than the max magnification of a normal lens, the comparaison should be at same focal distance and same distance to the subject.

for exemple two lens at 105mm, one is a macro, and both focus on a subject at 10m to the front of the lens, then the macro lens's magnification is bigger or not

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https://www.flickr.com/photos/jinlong-wang/

No. At the same focus distance a 105mm macro lens is the same as any other 105mm lens. The difference is that the macro lens can focus closer than a non macro lens.

thebustos said:

The 1:1 ratio of a macro lens means that the image it projects onto the sensor is the same size as it is in real life. So for instance, a coin 1cm wide will be projected onto 1cm of the sensor.

The reason you couldn't find anything in a Google search is because i think you've misunderstood how a macro lens' magnification differs from a non-macro lens. A macro lens is able to achieve higher magnification because it can focus closer than a non-macro lens.

If macro lenses were able to achieve a greater magnification at all distances it would simply be a longer focal length.

A 100mm non-macro lens and 100mm macro lens will give you the same image at the same distance everything else being equal. But a macro lens will be able to focus closer than a non-macro lens of the same focal length.
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Good luck and happy shooting!

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All the 3 answers are right, thanks all of you, i understand now.

This is the most clear so I selected this one, thank you.

Good luck and happy shooting

It's odd that people talk about "magnification" when the image is almost always smaller than the object.

At 1:1 it is of course the same size, and it is only when you get beyond 1:1 that there is really any magnification. At normal distances, there is a diminution. At infinity, the diminution is infinite.

There is no actual "magnification", (except the normal result of the lenses focal-length -- so a 100mm will indeed have twice the magnification than a 50mm AT ALL DISTANCES).

The difference is that a macro-focusing lens allows you to GET CLOSER, (and focus sharp), so eventually your photographed subject/object can be the exact same-size as your sensor, (1:1).

It can be noted that (because of the inherent "magnification" difference between a 50mm and 100mm), the 1:1 can be achieved further-away with the 100mm. Thus that is sometimes desired if you are shooting insects that may be spooked the closer you get, (and you can get "sun-shadows" from your camera/lens w/ 50mm since you do indeed have to get (2X) "closer" with a 50mm than 100mm).

The other difference with a "macro" lens is that they are often designed with a "flat" focusing field because they are often used to photograph (flat) books and papers.

There is another term, other than "magnification ratio" that I think is a better term: It's "reproduction ratio" and doesn't imply that the image is magnified [which it normally isn't].