# Thread: Need some help regarding lenses magnification

1. ## Need some help regarding lenses magnification

I did a quick lookup regarding lense magnification but couldn't grasp the concept.
Let's say I have a 24mm lenses that gives a magnification of 0.16x ( Or 1:6.25) have a minimum focusing distance at 0.25m. If I want to find the effective magnification on a 1.6x
crop factor camera, do I use the effective focal length (38.4mm) in the calculation, as in if
I'm using a magnification calculator?

2. ## Re: Need some help regarding lenses magnification

The magnification remains the same whether the lens is used on a crop or FF body.

Magnification = size of image (on sensor/film) / size of actual object

The image size remains the same for the same lens at the same distance (focusing does affect the image size somewhat for most lenses).

3. ## Re: Need some help regarding lenses magnification

if you use your 24mm in FF (24mm X 36mm), you can take a picture of on object the size of 150mm x 225mm.

if in crop (15mm x 22.5mm), object size is 93.7mm by 140.6mm.

do the math > 24/150 or 36/225 or 15/93.7 or 22.5/140.6 = 0.16

4. ## Re: Need some help regarding lenses magnification

Okay thanks guys!

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