Sigma vs Tamron: how are they viewed?

I am new to 3rd party lenses. How are Sigma and Tamron generally viewed against each other in terms of market share, IQ and build quality? And how are they viewed against Canon itself?

Is Sigma vs Tamron like Toyota vs Honda?
Is Canon vs (Sigma/Tamron) like Intel vs AMD?

Thanks

From what I understand Tamron makes a lot of the lenses for camera companies that don't specialize in lenses such as Panasonic ("leica lenses" made in japan...), Sony, etc.. And Tamron's optics technology is hardly matched, even by the likes of Canon and Nikon (oops, sorry, the N-word). But in terms of other analogous comparisons, I'm not sure... maybe like Canon vs. Epson? - in some cases Epson is really good, but Canon is good in others??

I voted for the Sigma as they got huge lens lineup with HSM and OS (optical stabilizer) equiped lenses. They seem much superior technology wise. Optically they are from the same league but Sigma do surprise with unanticipated lenses which are tough to design such as 12-24mm and 120-300 2.8

Both make a number of very good lenses with some features (Sigma's HSM, for instance) that rival Canon's best. Tamron's 17-50 and 28-75 and 90 macro, among others, are well-regarded; as are Sigma's 17-70, 10-20, 50-500 and other telephoto zooms and primes.

They also produce (as does Canon) lenses that are not well-regarded. You cannot determine the suitability of a lens exclusively by brand.

I agree with runninmann: you have to pick on a lens-by-lens basis.

I like the Sigma 50/2.8 macro, and I also like the Tamron 28-75/2.8

totally depends on the lens. sigma has hsm though but not in enough of their lenses

I voted for Sigma but reluctantly as you really can't make broad generalizations about lenses. Having said that, this is what I'll say.

Sigma offers HSM (their version of Canon's USM) a broad array of lenses, offer OS (their version of image stabilization) and most pro grade if not all the lenses come with a hood and a bag. Some lenses that they make have no Canon equivalent such as
50-500, 18-200 OS, 120-300 f2.8, 70mm macro, 8mm fisheye, and such.

Tamron has a SP Di/ii line for pro grade optics made for dslr's. However, their AF motors whines and the MF ring rotates with focusing, and they are build feel is cheap and plasticky. The optics of the SP Di/ii line cannot be faulted though. Their lineup is pretty limited though. I think they justify the plastic build by offering a slightly lower price.

Another company is Tokina. They have a ATX-Pro D/Dx line for pro grade lenses made for dslr's that are quite good as well such as Tokina 12-24, 10-17 fisheye, and 100mm macro, 50-135 f2.8, and the upcoming 16-50 f2.8. They are built very well and optically are excellent as well.

baw5t0n wrote in post #2626043
From what I understand Tamron makes a lot of the lenses for camera companies that don't specialize in lenses such as Panasonic ("leica lenses" made in japan...), Sony, etc.. And Tamron's optics technology is hardly matched, even by the likes of Canon and Nikon (oops, sorry, the N-word). But in terms of other analogous comparisons, I'm not sure... maybe like Canon vs. Epson? - in some cases Epson is really good, but Canon is good in others??

For clairification, Panasonic lenses are made by Leica and Sony's point and shoot use Carl Zeiss. Sony's SLR lenses are made by Sony with the exception of three. This information was given to me by the manufacturers themselves at CES a couple of weeks ago.

Tee Why/Tom is on the mark.

Thanks for your opinions guys. I know that you cannot make such a broad generalization, but I just wanted to know how the overall company stands and which is more popular. I am deciding between the sigma 17-70 and tamron 17-50 to replace my canon 17-85 IS. I was concerned about sigma especially since I cannot seem to even find the 17-70 at places like B&H or buydig. Am I missing something or is it just that these companies don't like carrying Sigma?

pythagpython wrote in post #2626246
I am deciding between the sigma 17-70 and tamron 17-50 to replace my canon 17-85 IS. I was concerned about sigma especially since I cannot seem to even find the 17-70 at places like B&H or buydig. Am I missing something or is it just that these companies don't like carrying Sigma?

Both the 1770 and 1750 are good choices. As for B&H and the Sigma, http://www.bhphotovide​o.com …EG&addedTroughT​ype=search

Thanks LightRules, I somehow didn't find that. But doesn't it seem that fewer places carry popular Sigma lenses? Not to mention a lack of reviews of Sigma lenses from the likes of BobAtkins.

Yea, but the Panasonic lenses labeled as Leica 14-45 OS is actually made by Sigma and Tamron used to make lenses for KM which are still available for the Sony A-100.

pythagpython wrote in post #2626278
Thanks LightRules, I somehow didn't find that. But doesn't it seem that fewer places carry popular Sigma lenses? Not to mention a lack of reviews of Sigma lenses from the likes of BobAtkins.

I think it's b/c Bob is supplied with Canon and Tamron lenses from Amazon or some online store. There are reviews of Sigma lenses at photozone.de, photodo.com, popphoto.com, and slrreview.com

If you are thinking about Sigma 17-70 vs Tamron 17-50, I'd probably go with the Tamron for it's speed and optics. If you really need the range, the Sigma 17-70 maybe better.