Question About Sigma vs. Canon Lenses (specifically speed)

astrostu · Mar 19, 2007

As some of you who have helped me on my "wide angle lens" thread, I'm trying to plan out what "pro"-level lenses I'm going to buy over the next few years.

What I'm doing is effectively going through catalogs of lenses that work with Canon cameras and excluding lenses that are specific to the APS-C sensors (so that the lenses will work when I upgrade to a full-frame digital sensor in a few years).

Before I post my final candidates for comments and suggestions, I have perhaps a basic question: What's up with the speed of Canon vs. Sigma lenses? Comparable Canon and Sigma "Wide Angle-Telephoto" lenses (like ~25-70 mm) seem to be around f/3.5-4 for Canon and f/2.8 for Sigma.

Is there something I'm missing here? As far as I can tell, other than the name, Sigma seems to have faster lenses than Canon, and I'm really looking to get as fast a lens as possible without spending over $800 for a single lens.

So yeah, what's up with that? Is there something obvious I'm missing?

Big Mike · Mar 19, 2007

Canon has lenses that are just as fast (large max aperture) as Sigma does...both companies have lenses that are fast and lenses that are slow.

Canon has a 24-70 F2.8 L lens, which is a top of the line lens. Sigma also has a 24-70 F2.8, it's much cheaper than the Canon but the Canon is a better overall lens.

Canon also has a 24-105 F4 L IS, which is a pretty good lens.

Canon line up

shingfan · Mar 19, 2007

honestly.......if you are able to afford a full-frame digital sensor in a few years (less than 5 i say)......you can afford expensive lense....so i dont think you have too much too worry there in terms of compatibility (full frame is still very expensive and i wont see a dramatic price drop in a few years....not sure about later though)

regarding the quality of Sigma and Canon (brand name)...i'm sure there are difference in quality.......i dont have a Canon so i cant give you much technically....but you pay for what you get.....you cant compare a $500 Sigma f2.8 to a $1500 Canon f2.8....i'm sure the quality is different...and Sigma DOES NOT make lense faster than Canon....they are just at different price figure........if you want a fast Sigma below $800....i have a good suggestion for you...get the Sigma 30mm f1.4.....i tried it and love it.....very sweet......this is as good as you can get with your budget if you main concern is speed...or you also want ZOOM?.^_^