QUOTE(julchin_09 @ Feb 23 2008, 04:49 PM)
I second that. But sometimes there are those who have deep pockets that spend unnecessarily without utilizing them to its true potential. We choose which side we want to be in. 3rd party lenses can do the job too.
I agree with 3rd party lenses. It all depends on value. Canon/Nikon has this focal range, the Sigma/Tamron/Tokina also has them. Better, they put in internal focusing, low dispersion glass (at least one glass molded one), aspherical glass (at least one) and include a hood for each of their products. Sometimes I feel these lenses has better CA and flare control than Canon/Nikon ones. These 3rd party manufacturers are beginning to catch up with better focusing motor especially Sigma with its HSM + FTM and the recent introduction of OS and VC for lens stabilization. Best thing is they come at a nice attractive price.
The only down point is reliability and consistency. Some of these lenses are not built as tough as some L lenses of the Canon. Some may be sharp with a certain body but when you upgrade to another body, it might require calibration. You need to send them to 3rd party manufacturers to do it. In this case, you camera body must go in too. I don't know if Canon will object to this or not but thats what I know. Then comes with the issue of compatibility with AF bodies. Some might require re-chip, but that is considered anti-competitive in business tactics if they purposely change their AF wiring on every new body... so I'm not sure if this is still the case.
So if you are buying a new 3rd party lens, that is not a problem because you can always try before buying. The concern only happens when you upgrade your body. No guarantee you will get the same performance because calibration might be slightly off. So you can try each and every body until you find a good combination before committing your purchase lor...
In my opinion, any lens will do as long as they have the focal range and aperture we require, has good optics performance and other features and all comes at an attractive price. Don't care if it is from Canon/Nikon/Tokina/Tamron/Sigma... who can give me this things, I'll buy from them. Consumers always get the most value for money and quality goods.