What's these numbers on the lens mean?

[keller]

On my camera lens there are some numbers:

5.8-23.2mm 1:2.6-5.5


I have an idea they're to do with the size of the lens, but I can't seem to decipher them. Anyone got any ideas?

 

[duncanp]

5.9-23.3 mm is its focal length , so you have around 4X xoom, 2.6 is the minimum aperture you will be able to achieve zoomed all the ways out where 5.5 is the minimum aperture you will be able to achieve zoomed all the way in. basically you will be able to get a shorter shutter speed zoomed all the way out and one 3X longer zoomed all the way in.


someone correct me if i have gone wrong...

 

[darich]

I think 2.6 and 5.5 are the maximum aperture and not minimum.
Small f number means big hole to put it crudely so i think that would be maximum.
But then I sometimes get them the wrong way round so someone may correct me!

 

[Hertz van Rental]

f2.6 is the maximum aperture when the lens is at 5.8.
f5.5 is the maximum aperture when the lens is at 23.3.
The diameter of the aperture (the size of the hole) doesn't change but stays the same. It is the relationship between the diameter of the hole and the focal length that changes.
The relationship being:
focal length/diameter of aperture=f-number