What benefit do primes have?

I don't understand why someone would use primes unless they are going to be the same distance from their subject like for instance; portrait work. I would rather get more of my subject in the frame without physically moving more far or near... or you could crop.

So far the things I can think of though are:
price
size
weight

generally do they get more light in? Do they take better pictures?

primes generally have a bigger maximum apeture.. you can have a f/1 prime but not a zoom to my knowledge

primes are also much sharper compared to most zooms.. some exceptions tho

Generally better quality, sometimes faster. Stop being so damn lazy and use the original zoom: Your feet.

(Note: I am lazy and tend to use the camera to zoom. But I don't complain about it )

I like to take a lot of shots in clubs and public places to where I can't get as close as I would like. I just do not want to switch lenses every shot

How much sharper are we talking here?

The first zoom lenses ever made were some way off of primes, image-quality wise. New lenses are so much better that the difference between primes and zooms is way smaller these days, particularly if you are talking about good quality ~(ie expensive ) lenses - L or not. Serious pixel peeping would reveal differences, but they are pretty subtle. I sure would struggle to spot the difference.

To be honest the main advantage of primes now is simply that they are usually a lot faster - for instance the 35mm f/1.4 , the 50mm f/1.2 and the 85mm f/1.2 for instance ( note these are all L lenses)

however even the cheaper primes- 35mm f/2.0 and 50mm f/1.8 are still pretty fast, and third party lenses such as the Sigma 20mm f/1.8 and Sigma 30mm f/1.4 are options that should be considered too.

There are quite a few advantages, some of which may be subjective based on ones' individual wants/needs/desires:

A prime will be smaller and lighter to a zoom of comparable image quality. I don't care for the size and weight of the zoom lenses that would yield the image quality I'm looking for. I'm able to carry my entire kit in a very small bag, which allows me to be more mobile while shooting.

Speed/DOF. For low light shooting, primes are king. While some of the IS zooms will perform well, the ability to shoot at f/1.2-f/2 is more desirable when one really wants to isolate a particular element of a scene.

Now, the usefuleness of primes can also be dependent on subject matter. For sports, wildlife, or shooting the kids, one may want the flexibility of being able to zoom. For my uses (landscape, still life), there's no need for that.

Just my two cents....

I only have the 50mm 1.8 and i find it alot sharper than any of my zoom lenses.

Ill defo get more primes in the future!

That one I AM going to buy is 50mm 1.8 II

primes are generally sharper than their zoom counter parts. also, they generally have wider apertures, while maintaining a smaller size than zooms. In the case of telephoto primes, among other things, they focus much faster than zooms.

Photolistic wrote in post #2067418
That one I AM going to buy is 50mm 1.8 II

That lens may have some issues, but there's no denying that it's THE gateway prime... for many, that's the first prime they try, and it typically leaves them wanting for more.

lol.... what issues does that lens have??

its not the best built lens on the block (very cheap feeling), is slow focusing, and not THE sharpest prime out there, but still sharper than the kit lens.

well, it's a plastic build (hence the price) but it's good quality none the less.

I like primes because they force me to explore my creativity and subject much more. I shot with only a 50 for about a year just to get myself to start thinking about my photos, it's so much easier to just zoom in and accept the angle you're at or the view of whatever you're shooting that you have, when you have to move around it's more interesting and makes you think and adapt. That's why I like em. Plus, as everyone else has said, they're usually better build and better optically then zooms.

think about cars. If you want a car with better gas milage, you get a little commuter. If you need to haul dirt or furniture all the time, you get a truck. While you could comprimise and get an SUV, you'll be getting bag gas mileage when you have to cummute and less room when you haul. This isn't saying that sometimes zooms aren't good, I have 2 of them and I use them, it's just saying that things built for specific reasons tend to do their exact job better than things build to encompass a broader area of tasks.

You summed it up pretty well in the original post when you said Price, size and weight. You could add to that speed and sharpness, plus the AF is often faster and funnily enough the manual focus usually has a better feel to it too. There are of course disadvantages... Obviously not as versatile as a zoom, and you'll do way more lens changes with the risk of dust getting onto the sensor.

On balance, usually a prime of a specific FL will do a better job than the zoom at the same FL but it's useless even 1mm either side of that. Some zooms run them pretty close though. It's really down to how you like to work, they suit me fine but I wouldn't expect everyone to agree with that.

You can probably tell which side of the fence I'm on by the sig!
cheers
Bill