Sigma or Tamron 70-300?

[KentuckyHouse]

I'm looking to pick up a used zoom lens and I'm torn between these two. After much searching, I can't seem to find any good comparisons between them.

Tamron AF 70-300mm f/4.0-5.6 SP Di VC USD XLD

or

Sigma 70-300mm F/4-5.6 DG OS

I'm not looking to spend money on L glass at this point (I'm using the Canon T4i), and these would be used for wildlife and some sky photography (particularly the Moon and Comet Ison).

Obviously I'll be using a tripod for the nighttime sky photography, but IS is a must for the wildlife.

By the way, the Tamron would be around $350-400 and the Sigma would run $150-200. Is the Tamron worth twice the price?

 

[toughsamurai]

Why cant you try the Canon EF 70-300 mm f4-5.6 IS USM. Its on sale now you can get a new one for 399.99.

 

[KentuckyHouse]

Why cant you try the Canon EF 70-300 mm f4-5.6 IS USM. Its on sale now you can get a new one for 399.99.

I didn't realize it was on sale. I'll check that one out as well. Thanks!

 

[jaomul]

Don't know about the others mentioned but the Tamron is a good lens, and highly rated review wise also. I had it on a 5d and 7d and 1d2 and it was solid on all of them

 

[Lumens]

I have the Canon EF 70-300 mm f4-5.6 IS USM on my 7D and find for Outdoors Wildlife it is my go to lens. I figure the next step up is the "L" lenses once I hit the lottery