I often see sentences like this in lense reviews:
"Another noteworthy specification of the 24-120mm f/4 S is the maximum magnification of 0.39x. That’s very high for anything other than a dedicated macro lens; it means you can fill the frame with a subject that’s just 3.6 inches / 92 mm across (assuming a full-frame camera)."
Can someone explain that sentence to me? What is maximum magnification and why should I need to know about it?
Thanks for your help.
I think, the best you can do is read this article : https://photographylife.com/what-is-magnification
However, my own written explanation if ever it can help ;) :
Maximum magnification is about the maximum size a subject will have in a picture's frame when you shoot it at the closest distance you can focus with a given lense.
So the more a lense is able to allow you to be close to your subject while in focus, the bigger magnification number can be.
So it's a specification that talks mainly about the ability of a lense to shoot close-up subjects and get them big in the frame. It's also an indicator of versatility.
About the magnification number itself and it's meaning, given we are talking about Full Frame camera sensor (36mmx24mm sensor size) :
1x number (also noted 1:1 as ratio) means that when you are at the shortest distance where the lense can focus, the subject is seen as big as it is projected on the camera sensor : i.e. a 36mm wide subject will fill the whole width of the sensor/frame. 1x is also known as the standard macro magnification.
0.39x number (somewhat 1:2.5 or 2:5 as ratio) means a subject as wide as a Full Frame camera sensor will be projected at a 0,39x36mm=14mm width on the sensor. So you need to have a 92mm wide subject to fill the width of the sensor (as said in the text of the review you quote).
etc..
@prg-lagarde Thank you for the clear explanation. It makes sense to me now. I actually did a little experimenting last night to test different lenses.
Also, I should have known PL would have an article on it already, right?
In the context of lens reviews, "maximum magnification" refers to how much a lens can enlarge a subject in the frame. It’s a measure of the lens's ability to capture small details, and it is particularly important when photographing subjects up close.
A magnification of 0.39x means the lens can capture an object that is 0.39 times its actual size on the camera's sensor. For example, if you're shooting a subject that is 92 mm (about 3.6 inches) wide, it will fill the frame when shot with this lens. This is a high level of magnification for a standard lens, indicating that it can take relatively detailed close-up shots, though it’s not a true macro lens (which has a 1:1 magnification ratio).