magnification

n. act of magnifying, state of being magnified; process of enlarging; something which has been enlarged

Magnification is the process of enlarging something only in appearance, not in physical size. Magnification is also a number describing by which factor an object was magnified. When this number is less than one it refers to a reduction in size, sometimes called minification.Typically magnification is related to scaling up visuals or images to be able to see more detail, increasing resolution, using optics, printing techniques, or digital processing. In all cases, the magnification of the image does not change the perspective of the image.
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Noun
1. the act of expanding something in apparent size
(hypernym) expansion, enlargement
(derivation) magnify, amplify
2. the ratio of the size of an image to the size of the object
(hypernym) ratio
(derivation) blow up, enlarge, magnify
3. making to seem more important than it really is
(synonym) exaggeration, overstatement
(hypernym) misrepresentation, deceit, deception
(derivation) overstate, exaggerate, overdraw, hyperbolize, hyerbolise, magnify, amplify
4. a photographic print that has been enlarged
(synonym) enlargement, blowup
(hypernym) photograph, photo, exposure, pic
(derivation) blow up, enlarge, magnify

(n.)
The act of magnifying; enlargement; exaggeration.
  

the optical image size divided by the object size.