Suggestions for building a lens system for 6D

neilroy wrote:

Thank you all so much for these suggestions. I am clearly spoilt for choice here, never a bad problem to have. I tried out the 100-400 in the camera store nearby, oh man, its just awesome! So, I think its between the 70-300 and 100-400. Somehow, I don't like the idea of a teleconverter.

Another quick question. My little brother has a 7D, and i want to gift him a couple lenses. He is learning landscape photography. So, I was checking out the EF-S 10-18 F/4.5-5.6 and the EF-S 10-22 F/3.5-4.5. Any thoughts on the non-L lenses for the 7D at all? I really appreciate your advice.

Cheers, Neil.

My understanding of crop sensors, and teleconverters for that matter, is that they do not use the whole resolving power of a lens made for 35mm FF cameras.

This makes sense if you think about it -- every lens is designed to focus all the different wavelengths of light onto a certain spot a certain distance behind the lens. This image must be a certain size. Since most modern lenses are based on designs dating back to the 35mm days, these lenses will create an image perfect for a 35mm/FF sensor. If you place a smaller sensor in the same location, you will get a fraction of the image (losing the outside edges). So the lens outputs a full 35mm frame as it is designed to do, but a crop sensor only records the center of it.

If the crop sensor does not have the resolving power to go beyond what the lens gives it, then it just means that you are paying for and carrying around more glass than you really use.

If the sensor can resolve more than it is receiving, then in theory, a lens could be designed which is both lighter and cheaper that would give you a better picture as well if it is designed for a crop sensor.

I could be wrong...