Confused on lens's-Quick question

[JeremyD]

I am fairly new to photography and sorry to ask a noob question but I am wondering why someone would get a fixed 50mm or 35mm lens if one can get a 18-55mm for example and be at 50mm or 35mm with that lens? Thanks for viewing

 

[bobandcar]

It's all about the aperture

And the sharpness

 

[cgipson1]

Primes traditionally have better IQ (Image Quality) than zooms... especially the lower end zooms. Primes are also cheaper then the more expensive zooms that do have excellent IQ. Primes also typically will have larger aperture capability than zooms (usually F 1.2, F1.4 and F 1.8) whereas inexpensive zooms usually start around F3.5 to F4,and then as you zoom out change to F 4. 5 to F 5.6, they are not constant aperture like primes, and some expensive zooms are.

does that help>

 

[480sparky43 42]

Very few zooms can compete with single-focal-length (prime) lenses when it comes to image quality. When judging a lens, you need to know how well it performs in terms of chromatic abberation, coma, sharpness, vignetting, contrast, color rendition, distortion, et al.

And exceedingly few zooms can compete with a prime when it comes to small size, large maximum apertures, low weight and still maintain a low price.