Canon S3 zoom power

[MarkString]

Today I was looking at a S3 with it's 12x zoom lens. But looking through the camera at full zoom, the image didn't look as magnified as it would through my 10x binoculars. Can anyone explain how much magnification the S3 has by comparing it to a pair of binouclars? I mean does he 12x S3 lens equal the magnification of a 12x pair of binos?

Thanks
Mark

[rinniethehun]

The zoom rating for a digicam has no bearing on the zoom rating for binoculars. The binocs 10x refers to 10 times normal vision (or no magnification). The x rating (sounds kinda funny when you put it that way) in digicam zooms refers to a ratio of the shortest focal length to the longest In the case of the S3 IS, its zoom range is 36mm to 432mm, or 12x. Assuming 50mm as normal vision (close), this would result in a magnification of 8.6x.

Hope that helps.

the Hun

[Sintares]

The x12 you see is simply the ratio between the maximum and minimum focal length of the lens.

Eg 36-432mm in 35mm film equivalent terms. 432/36 = x12

So since its a simple ratio, any lens with the same ratio could be described as x12 eg a lens 10-120 is x12, so is 50-600 etc

The X number is really only used to market cameras, since its an excellent way to impress newbies to photography.

[MarkString]

Thanks guys. How does one compare focal length to normal vision?

[slipe]

MarkString wrote:

Thanks guys. How does one compare focal length to normal vision?

The normal method is to divide the focal length by 50 as the Hun said.

There were different opinions back in the old days. Some said it was actually the diagonal of the 35mm frame which is 43.2666mm. Some said it was 57mm – I have no idea of the reasoning but my 57mm prime lens looked perfect when I left the other eye open and compared it with the viewfinder.