Sigma AF 18-200mm f/3.5-6.3 DC OS (Optical ...- User Rating: 
Summary for Sigma AF 18-200mm f/3.5-6.3 DC OS (Optical ...- Comparing the Sigma to the New Canon 18-200mm IS Lens
Notes on Sigma AF 18-200mm f/3.5-6.3 DC OS (Optical ...- I've had the Sigma 18-200mm OS lens for several months and found it to give sharper images with my 40D than the Tamron 18-250mm (non-IS/OS) which it replaced. Then along comes the new Canon EF-S 18-200mm f/3.5-5.6 IS, their own superzoom "travel lens." I bought one to see how it compares to the Sigma. My tests show mixed results regarding image quality. With both lenses wide open the Sigma wins at the wide end from 18-24mm, especially away from the center, while the Canon wins at the 135-200mm long end, also especially away from the center. The Sigma is f6.3 wide open at 200mm while the Canon is f5.6. This is only a small difference, but it does give the Canon even more advantage at 200mm where shutter speed needs to be the highest.
Both lenses auto-focus accurately (no front or back focus) although the Sigma is slower to lock focus in low light and is a little noisier in getting there. Their IS/OS are equally effective at about 3 stops of compensation. Build quality, size and weight are about the same and both use the same 72mm filter size. Sigma includes a lens hood while Canon wants to sell you one.
In summary, the Canon is slightly better for me due to the faster and quieter low-light focus and improved telephoto image quality. The trade-off is poorer image quality than the Sigma for wide angle shots, even after stopping down. Finally, the Sigma lens costs about $200 less than the Canon at this time.
Sigma AF 18-200mm f/3.5-6.3 DC OS (Optical ...- User Rating: Summary for Sigma AF 18-200mm f/3.5-6.3 DC OS (Optical ...- great daytime walk around lens
Notes on Sigma AF 18-200mm f/3.5-6.3 DC OS (Optical ...- I bought this lens when i bought my Canon XSi back in May. Its a great "walk around" lens. it covers a huge spectrum of range. For daylight photography and with a flash it works very well. My only real complaint is that its heavy and a little big... but this is expected with the 18 to 200 range.
IS works very well. At the 150 to 200mm range there is a noticeable difference between IS turned on and Off.
pared with the canon 50mm f 1.4 i think i have all the glass i'll need for a while. now its just a matter of learning how to use it well.
Sigma AF 18-200mm f/3.5-6.3 DC OS (Optical ...- User Rating: Summary for Sigma AF 18-200mm f/3.5-6.3 DC OS (Optical ...- Awesome Lens
Notes on Sigma AF 18-200mm f/3.5-6.3 DC OS (Optical ...- Lens is great. Can hand hold 200mm focal length at 1/30th sec shutter speed(without camera blur),when using the optical stabilizer. Would higly reccomend this lens. Rarely comes off my camrea. With 18-200mm focal length and the OS it is pretty much the only lens you will ever need!!
Sigma AF 18-200mm f/3.5-6.3 DC OS (Optical ...- User Rating: Summary for Sigma AF 18-200mm f/3.5-6.3 DC OS (Optical ...- Sigma all-around lense
Notes on Sigma AF 18-200mm f/3.5-6.3 DC OS (Optical ...- So far images are very good, functionality is very good also. This is a good "can take only one lense" on a trip, etc. I will be using this at Disney World after Thanksgiving...
Sigma AF 18-200mm f/3.5-6.3 DC OS (Optical ...- User Rating: Summary for Sigma AF 18-200mm f/3.5-6.3 DC OS (Optical ...- Had too much motion blur with OS on
Notes on Sigma AF 18-200mm f/3.5-6.3 DC OS (Optical ...- With the OS off, got nice sharp, no motion blur shots; with OS on, I got soft focus and always got motion blur. Almost made me think the switch was wired backwards on the copy of the lens I recieved. I returned it to amazon for a refund.
