who can tell me the meaning of word at the lens there??
just like AF Zoom 5.8-17.4mm 1:2.9-5.0
can any1 let me know??
Sorry,english poor..

http://www.photonhead.com/exposure/exposure.php

ohh...thanx for telling me...

AF:
- auto-focus

Zoom:
- means that the lens can change its focal length (angle of view, sort of)

5.8-17.4mm:
- tells u its a 3x zoom, take 17.4 / 5.8 = 3
- 5.8mm is the widest focal length
- 17.4mm is the longest focal length
- exactly how wide and long the angle of view is depends on the camera sensor size, i cant tell from here

1:2.9-5.0:
- the maximum aperture (basically how much light can the lens transmit)
- a smaller number means a brighter image, and thats a good thing
- at 5.8mm the lens is rated at 1:2.9
- at 17.4mm the lens is rated at 1:5.0
- as for most consumer lenses the more you zoom, the less light is transmitted

1 :2.9-5.0:
the first number " 1 "is meaning what??
aperture is 2.9 until 5.0??

1:2.9 - 5.0 means the maximum aperture at wide angle is f2.9 while at tele is f5.0.

but maybe those popular camera would not necessary to think that as a problem,yup?
how much aperture a popular SLR camera lens had??

A typical SLR kit lens with 3x zoom would have aperture specifications of 1:3.5-4.5

Don't worry about the specifications, if you are planning to take photography seriously, you will soon learn all about it and most importantly WHY and HOW you make use of such specifications to achieve the shots you need.

yeah ..i think the skill was very important~