18th May 2004, 12:03 AM
what do the terms on my lens mean?
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? Thanks in advance.
18th May 2004, 12:18 AM
7.1-21.3mm = focal length
1:2.8 - 4.9 = aperture
18th May 2004, 12:26 AM
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.
18th May 2004, 12:41 AM
18th May 2004, 12:46 AM
those are maximum apertures you are talking about
Originally Posted by Ah Pao