Everybody has had or has questions about lenses. I have placed links on these pages for information and opinions on different lenses. I also have a galleries site that has samples and comparisons of different lenses. If you have information or links that you would like to share then please e-mail them to me.
US vs Gray
There is no difference between the US and Gray lenses. They both are products of Canon Japan. The only difference is how they enter the US. It is Canon USAís policy to honor a one year warranty on all Canon lenses no matter who imports them. All you need to supply is a dated sales receipt. People are scared away from considering a Canon Gray lens because of Nikonís policy of not even working on Nikon Gray items. Canon USA takes care of all Canon customers.
Canon Consumer lenses vs L lenses
First let me start by saying that most of Canonís lens lineup are capable of producing good quality photos at least up to 8x10. Donít let people try and tell you that you need to use certain lenses on certain bodies. I have used a cheap 28-80 f3.5-5.6 II on a 1D and got nice sharp pictures. Canonís L series is designed for the professional. These lenses are made to withstand abuse and still maintain very high picture quality. Here is a link to Canonís explanation of L lenses. Most of the L lenses are worth the money but they are not needed to produce high quality pictures.
Want to know the age of your equipment? Try this link.
Some real world examples using different lenses.
Is Image Stabilization worth it? Here is an example.
Here is the link to Canonís EF Lens lineup.
Here is the link to Sigmaís Lens Chart.
Here is a link to lens reviews at Fred Mirandaís site.
Here is a link to a review by Bob Atkins on lenses for the Digital Rebel and the 10D.
Here is a post that tells you very briefly about the relationship between aperture, shutter speed and ISO setting.