Canon puts a great deal of importance on creating great fast lenses. In my opinion, they don't put enough on creating great small lenses. Fast lenses require a large entrance pupil and as a result have increased size and weight. Seems that most Canon users in the DPR forums are willing to tote the big, heavy glass in order to have the best image quality possible. However, bigger and heavier does not necessarily mean better image quality; it only means faster.

For instance, compare Leica M series 50mm lenses with Canon EF 50mm lenses. Leica has f/1 (Noctilux), f/1.4 (Summilux), f/2 (Summicron), and f/2.8 (Elmarit) M-series lenses at the focal length of 50mm. Owning no Leica M lenses, I don't know much about then; hopefully those who use them will correct any errors I make. The less fast Leica M 50s are more compact and less expensive (though still expensive by non-Leica standards). However, virtually all of these lenses are optically excellent and well made. Now the Canon lenses. The EF 50mm f/1.2L is fast, optically excellent (by my standards), expensive, relatively heavy, and has a wonderful build quality. The EF 50mm f/1.4 is optically excellent (my standards), is far less expensive, somewhat less heavy, and has a mediocre build quality. The EF 50mm f/1.8 II is optically very good, cheap, light, and poorly built. Manually focusing the 50mm f/1.8 II Canon is a depressing experience. Unlike the first version of this lens, there is no distance scale and the mount has been changed from metal to plastic. I have no experience with the EF 50mm f/2.5 Compact Macro lens and will therefore leave it out of this discussion.

By the nature of their design requirements, compact lenses must be slower. However, they do not have to be optically inferior or cheaply made. The Canon compact primes are not that optically inferior (this is subjective), though one might argue that they are not as optically good as they could be. However, they are somewhat cheaply made.

In some ways, the digital era has made faster lenses more important than ever. By far, the majority of Canon DSLRs sold have a crop sensor, making faster lenses the only way to get the shallow DOF that was possible with 35mm film cameras. However, for full frame digital users, faster lenses may be less important than ever since current sensor technology makes it possible to shoot with low noise at high ISO.

I hope that if and when Canon decides to replace some of their most compact and light primes (EF 35mm f/2, 28mm f/2.8, 24mm f/2.8, etc), that they raise the build quality a lot, raise the image quality some, and charge more accordingly. I'd also like to see them improve their compact zoom lenses.