How to know which lenses fit your camera?

I have a sony a55 and I've been looking on amazon trying to get a 75-300 or something-300mm lens for my camera and a lot of them say for sony, nikon or canon digital camera or something like that. I want to be sure it works on mine though so how can I be 100% sure that they will fit mine?

If its a generic one it may fit if it says your specific camera is acceptable.
Also google your camera plus the lense and see if any answers or videos come up about it

I prefer to use native lenses. They cost a little more but at least i secure

What you need to look for are lenses that use the Minolta/Sony "A" or "ALPHA" mount. So long as it says either "A" or "ALPHA" the it will be compatible, if it says anything else, then it will not fit!

Looking for a 75-300mm lens then the Sony branded lens is as good as any, and if you go to a physical shop you can probably barter the price (with cash rebates) as low as you can get this for on-line!

Your Sony Alpha uses A-mount lenses. And Sony isn't your only option. Tamron and Sigma make A mount lenses. It might also be called Minolta or Sony mount.

Hit up ebay. Any auto focus Minolta lens will work with your Sony Alpha there are millions of Minolta lenses made from 1985 to around 2005 when Sony bought them out. One last thing, are you sure you want a lens with that much reach? Zoom is overrated. You are going to lose image quality, sharpness and light transmission with that big lens.

Join http://www.dyxum.com/ if you haven't yet. It's the biggest Sony/Minolta forum on the web, and they have a database with all the information on every single lens ever made in A-mount.

Same brand, same mount. For your camera, make sure the lens description explicitly mentions your camera model as compatible. I'm aware there's an issue with Sony alpha lenses not working properly with SLT cameras but since I don't use Sony, I'm not sure which and how. It would be best to research on that very well before buying.

If you go to an authorized Sony dealer at the mall or at a store, they should be honest enough to tell you if the lens will work with your camera. That's something you won't get if you purchase online.

Check that it supports the Sony A mount. It tends to say something like "Tamron 70-300mm for Sony"

The Tammy 70-300mm is by the way a decent lens for a low low price.

Your A55 has the a mount, aka the modern old minolta mount and will accept old minolta glass auto focus glass and Sony lenses. But also Sigma, Tamron and other brands lenses as long as they are… You guessed it A-mount. Made for use on the Sony!

Make sure you buy a lens with the right mount and it should work just fine. Now there's on caveat, there are allot of older manual focus lenses out of the film age. And there are adapters you can screw on them to allow you to use these older lenses with modern cameras.

Sometimes you find one of these oldies sold like a "panagor 135mm F2, 8 for Sony" means that its a M42 or another mount lens with an adapter on it for Sony.

Now using old glass is fun but without AF so it is something you have to decide if you like it.