I got my hands on a Canon Rebel 4Ti the other day and it came with a fairly standard EF-S 18-55mm f/3.5-5.6 with IS v2 kit lens. I used to use this lens for my wide lens at one point. (actually bought one from ebay!) I was using it to shoot some ebay photos and was noticing I was getting some pretty bad “bloom” and things were looking pretty soft, so I decided to check it against my 24-105 f/4 L IS (which is the “kit lens” on some higher end cameras such the 5D MkII-III and I think you can get a 7D with that as a kit lens too). I also put it on my 7D for a double check. It was night and day! See the photos after the jump!
I think the 7D shot turned out worse because I was zoomed in more on that photo. The 7D and T4i both have 18MP sensors, so that wasn’t it.
Now, I don’t think my copy of that EF-S 18-55 IS II was THAT bad. I hope not at least. I thought it was pretty decent at the time except the corners. I think I even had the 24-105 at that point, but wanted a wider angle lens for my APS-C sensor, but didn’t do any comparisons like this apparently or the 10MP 40D wasn’t showing how bad this lens really was. (I use a EF-S 10-22 for my super wide angle shooting now)
I did a little more checking to see if it was possibly just not focusing correctly with that lens and that might be a little of it, but certainly not all. I auto focused and then took the same shot manual focusing in Live View at 10x. I got a slight improvement on manual but not much.
So the moral of the story is to sell your kit lens on ebay and buy a couple primes or a better quality zoom (even if it’s a 3rd party zoom, as long as it’s good quality) or just buy a nifty (thrifty) 50 (50mm f/1.8) when you buy your camera because they are incredibly affordable (about $100) but are a bit low on the build quality, so don’t bang it against anything. That lens or better yet, the 50mm f/1.4 (spend the extra $250 for better build quality and a little “faster glass”) is a great lens and will make you look better than you are as long as you can hit the narrow focus at f/1.4 (or f/1.8). (center focus dot on the nearest eye for people)
However, on a crop body, a 50 will be a bit to long in most case. Canon recently released a “pancake” 40mm f/2.8 that’s supposed to be good and that would equal about a 50mm on a crop sensor camera. or you could go with the 35mm f/2 which again, is about 50mm on a crop body.
What’s he talking about you ask: (multiply lens focal lenght x 1.6 for Canon APS-C “crop sensor” cameras to get the full frame/35mm camera equivalent) So a 50mm on a crop body will give you the same field of view of an 80mm on a full frame body.
As for a zoom that won’t cost as much as your camera. You might look at the Tamron 17-50mm f/2.8 XR Di II. It has good reviews on Amazon, but I don’t have any personal experience with it. At the least, it’s a faster, fixed aperture lens, but anything in the $500 range will most likely have some down sides vs. something that costs double or more (“pro glass”). (this has no IS and is probably still a bit softer or less constant through the zoom range/aperture extremes than the 24-105 L, but costs about half that price too) So if you are making family pictures and not selling them, this should probably be a fine lens.
You’ll probably get the best bang for your buck with the prime (non-zoom) lenses, but you will have to zoom with your legs, you’ll be either stuck with one focal length or changing lenses a lot, and most don’t have any image stabilization. Going with wider primes is probably better unless you know you are going to want to be zoomed in (zoo?), in which case the long primes aren’t as affordable as the shorter ones) 24mm-50mm (maybe 85mm) range is probably what you’ll want to look in in the non-top end (ie fastest) aperture models. For example, the 35 f/2 is a little less than $300, but the f/1.4 is $1300.