I'm learning photography and all its elements. Probably this question is really stupid, but I have to ask.
I'm not dealing well when the question is equipment and one of the reasons I know this is because of the negative comments in my answer:
When I asked that question, I didn't know these lenses are for diferents purposes. In fact, I still don't know. To me, they all look like Telephoto and I can take the same kind of pictures with them: birds, surfing and etc.
All I know about lenses's categories I learned here: http://www.usa.canon.com/cusa/consumer/products/cameras/ef_lens_lineup
But I don't understand several things, like:
How can (EF 17-40mm f/4L USM) be "Ultra-Wide Zoom" and (EF-S 18-55mm f/3.5-5.6 IS) be "Standard Zoom"? One starts with 17mm and the other one with 18mm, they look the same! In my mind, an wide angle lens should start, at least, with 10mm.
How can a (EF 50mm f/1.8 II) be "Standard & Medium Telephoto" and (EF 50mm f/2.5 Compact Macro) be "Macro"? They have the same focal length!
That's what I think it's true in the moment: A lens has two important aspects: focal length and aperture. That's all I have to care about. Of couse it's not correct, that's why I want some advices to get in the right way when I buy my next lens. So, what can I read to do the right differentiation between them? How can I know which lens is better for my purpose?
OBS: I'm a fan of the chosen answer in this question: How to choose a lens for my first DSLR? I love to keep things simple and I don't care too much about technical details. It can seems like a paradoxal stuff because of this question, but it's not. I'm asking this because I want to buy the right lenses without wasting money, but in the simplest way.