Macro aspect ratio? Aspect ratio is the ratio between the width and height. It's the same no matter what focal length your using, or what magnification.

Thats the ratio of size of image on film to size of acutal object. A 1:1 means the image size is just as big as the actual object. A 1:2 means the image on the film is half the size of the acutal object.

Sorry Arty, I didn't understand what you were asking. Zedin explained it. It's the "magnification" ratio.

Let's put it like this. Let's say you take a photo of a penny using a macro lens. If the macro lens says 1:1, that means that the image of the penny on the negative (or sensor) will be lifesize. If it says 1:2, it will be half lifesize. If you go the other way and it says 2:1, it will be double lifesize.

It's essentially basic fractions. Put the left number on top of the top and it gives you the magnification. 1:2 - 1/2 half magn. 4:1 - 4/1 4 times magnification.

lifesized or half lifesized refers to the actual image on the negative. If you took a picture of a 5mm*5mm square then on the actual negative the image of the square would be 5mm*5mm if you shot at a 1:1 ratio. If you shot at a 1:2 ratio the square on the film would measure 2.5mm*2.5mm.

If its 1:1 then its like a mirror except it doesn't flip the image. Half life size is if its 5mm tall in real life and is the focal distance away then the image will be 2.5mm on the film.

1:2 (which is the same as saying 1/2) is half lifesize. If you took a picture of a penny (as mentioned), 1:2 means that the penny would be half actual size on the negative or sensor.