How do you determine the optical magnification of lenses?

[marsulein]

Dear Photo Enthusiasts,

I've just picked up photography roughly 2 weeks ago and I am still very confused on how do you actually find out the optical magnification (a.k.a zoom) just by reading about the lens spec.

For example, let's take a look at this lens which I found from official Nikon website:

AF-S DX VR Zoom-Nikkor 18-200mm f/3.5-5.6G IF-ED

The website says that:

"AF-S DX VR Zoom-Nikkor 18-200mm f/3.5-5.6G IF-ED, a compact, lightweight 11.1x zoom lens that is ideal..."

How do you actually derived the 11.1x magnification from looking at the focal length information?

A very confused Noob,
Mar

 

[Redsun]

Dear Photo Enthusiasts,

I've just picked up photography roughly 2 weeks ago and I am still very confused on how do you actually find out the optical magnification (a.k.a zoom) just by reading about the lens spec.

For example, let's take a look at this lens which I found from official Nikon website:

AF-S DX VR Zoom-Nikkor 18-200mm f/3.5-5.6G IF-ED

The website says that:

"AF-S DX VR Zoom-Nikkor 18-200mm f/3.5-5.6G IF-ED, a compact, lightweight 11.1x zoom lens that is ideal..."

How do you actually derived the 11.1x magnification from looking at the focal length information?

A very confused Noob,
Mar

they actually got the 11.1x zoom factor by dividing 200/18

 

[aquaobsession]

=200/18
=11.1

 

[flipfreak]

think this thread shld answer most of your qns.

http://www.clubsnap.com/forums/showthread.php?t=380887

 

[Octarine]

=200/18
=11.1

That means a 70-200 lens has a lower zoom factor than a 17-50? Sounds rather weird and misleading... I prefer the real figures of focal length rather than such marketing bubbles of zoom factor.

 

[zac08]

That means a 70-200 lens has a lower zoom factor than a 17-50? Sounds rather weird and misleading... I prefer the real figures of focal length rather than such marketing bubbles of zoom factor.

This zoom factor is more for the PnS or Prosumers anyway....

I dun think any of the SLR users bother with it....

 

[night86mare]

How do you actually derived the 11.1x magnification from looking at the focal length information?

simply put, the most direct answer is 200/18

the maximum focal length on the lens, divided by the minimum

same goes for any p&s, but you shouldn't care about focal lengths, more about perspective.

 

[marsulein]

Thanks for the overwhelming response!! Truly appreciate that.

I particulary love the link in this thread, simple and not packed with all those confusing figures. Just what I am looking for!!

think this thread shld answer most of your qns.

http://www.clubsnap.com/forums/showthread.php?t=380887