Why buy Canon when third party are this good?

[Flake]

http://www.ephotozine.com/article/tamron-sp-24-70mm-f-2-8-vc-usd-lens-review-19056

This lens is half the price of the Canon version and it has VC (IS), when the results are this good what is the point in paying twice as much for a lens which hasn't even made it to market properly yet, weighs a ton & doesn't have IS?

[RLPhoto]

Very interesting article. Canon will definitely loose some sales to this lens, but I wouldn't buy it.

[Mt Spokane Photography]

Interesting, I'll be watching for other testers and see what they say.  It looks like 70mm is the weak spot.

[mitchell3417]

I had a Tamron. I sold my Tamron. Would take a lot of great reviews for me to go back to a Tamron.

[Bennymiata]

Probably the biggest difference between buying a genuine Canon lens or an alternative brand is resale value.
A good Canon lens will hold its value, whereas third party leneses do not.

Also, you have to consider the build quality and reputation, and I think that Canon has that in spades.

Tamrons are usually considered to be "cheap" lenses.
I'm not saying they are bad, as I own a few third party lenses that perform very well, but if I went to sell them, I wouldn't get anywhere near what I paid for them.

[mws]

No weather sealing, which is very important to some people. But for a more casual shooter, or someone who is just a hobbyist, there are some really great third party lenses.

[lol]

The backwards zoom is still an instant dealbreaker for me.

[tron]

I copy from another post of mine the reason I would think twice of buying 3rd party lenses:

I bought the Tokina ATX28-70 f2.8 by the year 1993. It worked fine on my EOS600 and EOS620 (and later I found out that it worked fine on EOS1n). When I tried to use it on a EOS50E (1996 or 1997) the camera was blacking out when I pressed the shutter release. Needless to say it does not work with digital bodies too 

My old Sigma 14mm - I say old because there was a newer edition of that lens - works ... a little on my EOS5DmkII Only when the aperture is fully open (You can only imagine the vignetting I get! I didn't even care to check the optical quality).

I didn't even know that there was at least a specific usable aperture until I saw at ebay a listing of a very old SIGMA 500mm that was reported to work with analog bodies plus with EOS5DmkII at open aperture (only). That gave me the idea to check my SIGMA lens.

Check:
http://www.ebay.co.uk/itm/Canon-EOS-Sigma-APO-500mm-1-4-5-Case-/170784321711?pt=UK_Lenses_Filters_Lenses&hash=item27c389f0af

"This lens will only focus on digital cameras like the 5D or 50D and work with an open aperture, you will get an error message if you stop down "

[DavidRiesenberg]

Tamron will sell a boatload of these things. I know I'd certainly consider it if I were looking for a 24-70.

[EYEONE]

I had a Tamron. I sold my Tamron. Would take a lot of great reviews for me to go back to a Tamron.

+1 I don't think I could ever buy Tamron again. The AF was a complete and total disaster. I'll take AF the way it was suppose to be over VC or IS (not needed on this focal length anyway) any day. I know this Tamron is half the price but it's not even an option in my mind.

[scrappydog]

No weather sealing, which is very important to some people.

From the article, "The lens sports a moisture resistant design and a thin rubber gasket has been placed around the metal lens mount to help prevent the ingress of dust and moisture into the camera body."  This sounds like it is somewhat weather sealed.

I really hope this lens sells well.  If third-party manufacturers elevate their game, Canon may be forced to be more innovative in their products and more prudent in their pricing.

[sublime LightWorks]

I had a Tamron. I sold my Tamron. Would take a lot of great reviews for me to go back to a Tamron.

+1.....sticking with Canon L glass, and in some cases Carl Zeiss.   Only lens other than these I might consider is the Sigma fisheye.

[mws]

Must have misread, I thought I saw a part about no weather sealing. Need more coffee.........

[stabmasterasron]

I had a Tamron. I sold my Tamron. Would take a lot of great reviews for me to go back to a Tamron.

+1.....sticking with Canon L glass, and in some cases Carl Zeiss.   Only lens other than these I might consider is the Sigma fisheye.

++1....sold my 17-50 VC.  Image quality was OK, but autofocus was a joke compared to ultrasonic from canon.  Maybe the new USD from Tamron will be good. 

[pdirestajr]

1. I have a hard time spending over 1000.00 for a 3rd party lens.

2. At that price, I'm expecting to last a long time. How will this Tamron lens look and operate after 5+ years of use?

3. I know that Canon lenses hold their value really well. Who is going to pay you close to 1000 down the line for a used Tamron lens?

4. They are also reversed engineered, what if Canon makes a change in the future that affects how 3rd party lenses play with them?