Canon EF-S 17-85mm IS USM vs 18-200mm IS
کد:
http://www.radiantlite.com/labels/dslr%20lenses.html
In conclusion
Overall Canon EF 18-200mm is sharper in the center across the focal length but worse in the corner. At telephoto end, from 150-200mm, this lens suffers dramatic color fringing.
Both lenses are not perfect, but they are good enough for casual use. Mechanically, 17-85mm has a better AF operation but 18-200 has better IS. 18-200mm has also longer focal length.
So does investing $175 more for 18-200mm worth it? it depends on your needs. Are you planning to use the lens for outdoor sport / nature? If yes than you will need 18-200mm otherwise, 17-85mm might serve you well.
Other alternative for general purpose lens in the same class (consumer class) are 28-135mm IS USM.