Questions about a "fast lens"

[Pariah]

I shoot lots of low light photos, and when I spoke to someone recently about wanting to take photos at concerts, they mentioned that getting a faster lens is a must for both situations. What exactly is a faster lens? I have a Nikon D80, can anyone suggest one for my camera? How much should I spend on one? I just have the kit lenses at the moment, because I'm really not sure exactly where I should go from here.

 

[frXnz kafka]

A fast lens is one with a very large maximum aperture. Something like f/1.8 or f/1.4 would be considered very fast.

 

[Johnboy2978]

As the previous poster noted, it is one with a very wide aperture. What makes the lens "fast" is that having that larger aperture allows more light to enter the lens, thereby allowing you to maintain a faster shutter speed. For a prime lens (that is fixed focal length) you can probably expect to spend about $200 average and it will generally have an aperture of 1.8 or maybe 1.4. For a zoom lens f/2.8 is about as good as you're going to find and they can be anywhere from $400 to several thousand dollars depending on the focal range, and what fancy features it includes (e.g. internal focusing, image stabilization,etc. and of course to have that nifty "L" on it if you are a Canon shooter - not sure what Nikon's mark is for their elite line of lens).

 

[sabbath999]

... not sure what Nikon's mark is for their elite line of lens).

The top quality glass is marked Nikkor...

 

[keith204]

I just received my 24mm f/1.8 Sigma. You can get one for a Nikon as well.

It was about $300, and I am AMAZED at the sharpness. Some f/1.8 primes you need to bump to f/2.8 or f/4 to get them real sharp, but this Sigma 24mm f/1.8 is sharp as a tack at 1.8.

Even with the weird 2-step manual focus, and the noisy autofocus, it is a great lens.