Old Topic? "Brand name" vs "Aftermarket"

[wsbII]

Hey everyone,
I spent some time searching the forums and can find some personal opinions, but nothing concrete on the difference in image quality between factory/brand name lenses (Canon, Nikon, etc.) versus the aftermarket lenses (Tamron, Sigma, etc.).

Specifically I'm interested to know if anyone has seen a comprehensive objective study of lenses of comparable cost (don't compare a $1500 lens to a $200 lens) to see if there is a definitive image quality. I believe that with a jump in price of a lens it is tied to image quality, but if lenses are comparable costs, then other than specific features (focal length, aperature, etc.) are they of equal quality? Those features will definitely sway a purchaser, but I'm just curious if the "brand" makes a big difference in equal cost range lenses.

Thanks in advance for any input or information that covers this...
Bill

[OsmosisStudios]

THe trick to comparing OEM (brand name) to aftermarket isnt to think money, but equivalents.

The Third Party manufacturers attempt to cover either identical, popular focal lengths (like a 70-200 f/2.8), just for a considerably lower cost. Or, they attempt to fill in spaces that arent available from OEMs (like a 50-150 f/2.8).

[candleman]

its tricky..

i had a Nikon 70-300 G f/3.5-f/5.6 its a plastic piece of crap
i now use a Tokina 75-300 f/3.2-f/5.6 ..... and its significantly beter (i got it for free when i bought a film camera set-up)

so as above,
look at the focal lengths you want to cover, then do comparisons on IQ vs Price from there, of lenses that cover tose ranges made by various manufacturers.

[Elmo]

There is no black-white answer to your question. You have to evaluate lenses on an individual basis. When you buy a top of the line camera brand lens you can generally count on a quality product. On the other hand if you buy a low end camera brand lens, third party lenses are most often better.

Also third party vendors generally do one type of lens better than other types. For instance Tokina wides are generally great, While Tamron mid ranges are usually very good. My favored lens for a "c" size sensor is a Tamron 17-50, repackaged as a promaster.

Third party lenses are a little better known for copy to copy variations than camera brand lenses.

So the best stab at an answer is to evaluate each individual lens one on one with the competition.

[wsbII]

Thanks for the feedback guys. I've noticed it is hard to say across the board if one is better than the other. just been discussing with a fellow photog the approach of always buying brand name versus third party (I have a few tamrons that are close to the same focal length and aperature range as his Canons). I just seem to always save a few bucks in going with the thrid party and haven't noticed any difference in performance. I do have some of both and thus have compared when making each lens purchase, guess that is the only right answer at this point...