what do the terms on my lens mean?


Status
Not open for further replies.

isis

New Member
Oct 8, 2003
172
0
0
#1
7.1-21.3mm
1:2.8 - 4.9

The above measurements are printed on my digicam lens.
Other than saying the cam has 3X optical zoom, i donno what's the significance of the rest. (ie. what do they mean exactly???)
Can someone kindly explain to me? :embrass: Thanks in advance.
 

Ah Pao

Senior Member
Nov 7, 2003
1,663
0
36
Singapore
www.facebook.com
#3
Or more specifically, your "7.1-21.3mm" means the focal length the lens can zoom. Taken on it's own, it's probably of no useful meaning except that it tells you it has a OPTICAL zoom ratio of 3x (21.3/7.1 = 3).

The "1:2.8-4.9" means that the lens, at 7.1mm focal length has an aperture of f/2.8, and at the longest 21.3mm focal length has an aperture of f/4.9. The aperture affects the amount of light received by the sensor, among other things. Technically speaking, the smaller the f-number the more light it can collect and can shoot better in low-light situations.
 

isis

New Member
Oct 8, 2003
172
0
0
#4
Thanks for the clarification. :) Can the 7.1-21.3mm be interpreted in any way to give other info, like optimal distance between cam & subject (what-do-u-call-this) etc?

I'm thinking of getting an add-on macro filter for my cam (want to improve my macro shots)... what range of "measurements" shd i be looking at for the filter? (Hope this isnt a dumb question!) :sweat:
 

mervlam

Senior Member
Apr 26, 2002
2,279
0
0
Visit site
#5
Ah Pao said:
The "1:2.8-4.9" means that the lens, at 7.1mm focal length has an aperture of f/2.8, and at the longest 21.3mm focal length has an aperture of f/4.9.
those are maximum apertures you are talking about
 

Status
Not open for further replies.
Top Bottom