Generic zoom lens for Xt

[Akage]

Hi Guys,

I'm completely new to the SLRs, so bear with me I've recently bought a Digital Rebel Xt and an EF 50mm f/1.8 lens. I really like the photos it does, however (from lack of experience obviously and from previous point-n-shoots) I didn't even realize you can't zoom with it, so now I'm looking for a zoom lens.
I've really tried to understand and convert the mm's to "zoom levels" (how much it zooms), but have failed. I've thought that the more mm's the more you can magnify, but from the lens reviews at http://www.kenrockwell.com I can see for instance that Canon 17-85mm doesn't get you as close as Canon 18-55mm EF-S II - so I'm back at square one.
Right now I'm on a budget so I'm looking at low-end lenses: Sigma AF 28-70mm f2.8-4 DG, Sigma AF 18-50mm F3.5-5.6 DC, Canon EF-S 18-55mm f/3.5-5.6 and the like - but I don't know if you can e.g. magnify at a bird 30 feet away with them, but on the other hand also shoot some general photos (like with EF 50mm). And unfortunately I have to buy it now, even though I don't know much about it, so I could really use some share of your knowledge
I'd appreciate any suggestions

 

[Big Mike]

Welcome to the forum

I've really tried to understand and convert the mm's to "zoom levels" (how much it zooms), but have failed. I've thought that the more mm's the more you can magnify, but from the lens reviews at http://www.kenrockwell.com I can see for instance that Canon 17-85mm doesn't get you as close as Canon 18-55mm EF-S II - so I'm back at square one.

Ken Rockwell...:roll:

The focal length of a lens is what determines the magnification. The 17-85 will get you more magnification than the 18-55 can. I think that what you must have been reading was the minimum focus distance (close up shooting). The 18-55 is probably capable of focusing closer than the 17-85...and so would be able to get closer (increasing magnification effect.)

On a tight budget, I would suggest the 18-55 (kit) lens. You can probably get a cheap one used because so many people have them.

When looking at lenses...bigger (maximum) apertures are better. That is represented by the F number in the name of the lens. A lower number is a bigger aperture. So, you 50mm F1.8 is a great lens because it has a large aperture. The kit lens isn't so great because it's maximum is F3.5 at 18mm and only F5.6 when zoomed out to 55mm. Having a zoom lens with a large aperture...makes it's expensive though. For example, the Canon 17-55 F2.8 IS lens will cost more than your camera.

 

[hudsonp]

I'd appreciate any suggestions

http://www.usa.canon.com/app/html/EFLenses101/focal_length.html

great little tool will actually show you the different "levels" of zoom


this one is good for learning about the lens that canon offers
http://www.usa.canon.com/app/html/EFLenses101/index.html

 

[ANDS!]

Why do people poo-poo on Rockwell? Seriously - Ive found alot of the stuff on his site to be a good resource. It his opinion of course, and its going to be controversal because of that - but on the whole, good resource for a jump off point.