What's the best lens for Canon 400D?

Answer 1

That depends on a few things. Mainly your budget and the zoom range you're looking for. Here are some options.
The kit lens is an 18-55mm. This is a decent zoom range for general photography - it should cover around 60% to 80% of your needs. In time you might want to add a second lens with something like a 70-200mm range. The 18-55mm is very inexpensive but the image quality is also rather poor. You won´t get the most out of your 10 megapixel sensor with this lens.
For around $500 you could get the Canon 17-85mm. This lens is much better in just about every respect (as it should be for that price jump.) It has more range, it has image stabilization, better optics, better build quality, etc. It's only 'weakness' is that it underperforms a bit at the wide end (from 17 to 24mm.)
If you shoot mostly wide angle, and need great image quality in that range, you could consider the Canon 17-40mm. It's a bit more expensive than the 17-85 however, and the zoom range might be too short to consider this lens a proper standard zoom. It´s great for street photography and landscapes, but you can´t zoom in for candids or details.
If money is no object, get the Canon 17-55mm f/2.8. It costs a whopping $1050 but it's the best you can get for image quality and low light performance.
For low light performance on a ´budget´, you could consider the $450 Tamron 17-50mm. It´s recieved great reviews (for the price).
All-in-one lenses such as the Tamron/ Tokina/ Sigma 18-200mm are also an option. You get loads of convenience for a relatively low price - around $300. But with these lenses you do sacrifice image quality and low light sensitivity. Canon only makes a 28-200mm zoom, but this lens doesn´t provide wide angle coverage on a 400D. All of these mega-zoom lenses are good enough for vacation snapshots etc, but as with the 18-55 that I began with, don´t expect to do any art photography.
And finally, Sigma has something of an in-between lens, the 18-125mm zoom. It costs about the same as the 18-200 zooms and it´s a better quality lens. This range should cover about 90% of your needs but again, it´s not nearly up to the standards of the more expensive lenses.
With a 400D, I would personally get the Canon 17-85mm. This zoom range is fantastic for what I do and I´m willing to pay for quality. I´d even be happy to buy the 17-55mm, but that lens would feel more at home on a 30D.

Answer 2

The best lens will cost a couple thousand dollars. I just got the same camera and I have a Tamron AF 18-200mm zoom with autofocus. The quality is really good. It works wonderfully and gives clear accurate pictures. The zoom is long. I think this lens is high in quality and a real good value for the money.

Answer 3

all depends on what you want.. for just snap shots, wide angle , telephoto? Here again the question was BEST.. how about what would be a nice or good lens. sigma and tamron both make fine lenses. I shoot with a Tamron 28-300 ,fit my needs.