Why do some lens say f/4L?

Question

does this mean it only has 1 aperture setting?

is larger the aperture better? i noticed alot of lens stop at 4

Answer 1

the f/4L ... f/4 refers to the widest aperture available in that particular lens... even if it is a zoom, it's f/4 throughout the entire range, you can make the aperture smaller, likely to at least f/32 or f/36... The same can be said for f/2.8L lenses...

if a lens says f/3.5-5.6  on a 70-200 lens.. then at 70 f/3.5 is the widest, and at 200 f5/6 is the widest.  

the "L" is for the "L" series of lenses that Canon manufactures.. the "L" stands for Luxury..

A prime lens has only one focal length, say 400mm ... where a zoom has a range of lengths say, 100-400mm

Answer 2

No - it means that the widest aperture (4) is available through out the range. so it means that f/4-22 is available to the whole range.

Having a constant aperture does not mean the lens is a prime.

It depends on how you want the background to look.

I have the Tamron 17-50 2.8. I like the way the background is blurred.

Answer 3

The aperture shown is the widest aperture that can be used on that lens. The lens is still capable of using smaller apertures.

A prime lens only has one focal length, such as 50mm or 100mm.

Yes, the larger aperture is better... especially if you like to shoot indoors.