## Maximum reproduction ratio.

the max. mag. possible at the closest focussing distance.

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Originally Posted by avan

Hi,

Im a bit confused about the term. My lens have a max repro ratio of 1:4, some other lens said 1:7, this is mean a 1:7 may look like appear bigger than the 1:4 ratio. Hope someone can explain.

Thanks

CannOffice

There are two possibilities here. The 1 - 4 could be the Zoom Ratio i.e a 75 - 300mm zoom has a 4 to 1 ratio. The Maximum focal length is 4 times the minimum. A 18-125mm is amost a 7-1 zoom range but the magnification at 125 would be way short of the 300 on the 4-1 so you can see that if you are refering to zoom ratio the figures are useless unless you give the focal lengths with them.

The other possibility is that you are refering to the maximum magnification possible at the closest focussing distance. In this case 1:4 could mean that the image recorded will be ¼ of life size while 1:7 would be 1 seventh of life size. These figures work regardless of focal length and often mean that to get the maximum magnification the lens is almost touching the subject.

I hope that this does not cause too much confusion and may even help a little.