Canon or Sigma lens?

[Canonfan]

Hi,
I am looking to buy either the Canon 100-400mm or Sigma 150-500mm lens for wildlife photography. I'm after advice on which lens is better, the Sigma is a cheaper lens but does it perform as well? I have a Canon 500D body with a Tamron 18-270mm lens on it but am looking for greater zoom capabilities.

Thanks

[I @ M]

You will get a truckload of advice from knowledgeable Canon proponents here on the subject to help with your choice but I do know that the Canon lens has produced some very worthy images on this forum alone.
I guess that you are the ultimate decider on the focal lengths needed and the depth of the credit card wallet so have a look at some of the wildlife and bird shots on here taken with both lenses as a little bit of a help towards your decision.

[Speedway]

I have the 150-500 and am very happy with it although if the 50-500 OS had been released at the time I think I would have found the extra dollars for it. The 100-400 canon is a much reguarded lens but the extra 100mm and the price difference swayed me.
Keith.

[andylo]

Canonfan,

Let me pans out the pro and con with both lens

Canon 100-400:
Pro:
L lens - suppose to have better build
Focus usually spots on
Accordingly to website info + personal experience, image coming out from this lens is SLIGHTLY sharper
The lust of white lens with red ring....

Con:
It's a 1998 technology! (12 years)
3 stops IS (vs Sigma's 4 stops)
Not weather proof
Push/Pull zoom - personally, I hate it!

Sigma 150-500
Pro:
Much newer design
4 stops IS
Cheaper in price - much cheaper IMO
100mm more focal length

Cons:
It's not weather proof neither!
HEAVY! VERY HEAVY
82mm filter required
Sigma lens on Canon body has track record of either front/back focus issues and required micro adjustment.

For the price difference and 100mm longer F/L, I personally would prefer the Sigma.

BUT!!!

IMO, Sigma is NOT the kind of lens you would like to try your luck and purchase thru ebay!! Between myself and my friends we have go thru a few lens but the Sigma on Canon body usually has either front/back focus problem. (Put it this way, we have bought/traded for about 12 Sigmas and only 2 are spot on re focus!) You will want to buy this from a proper shop in Australia, so you can get customer support from both your camera shop and CR Kennedy if micro adjustment is required, especially on a body cannot do MA (500D)

But once you got a copy that is either spot on re-focus by default/adjusted, you then have a great tool to create absolutely stunning image

[selaw]

especially on a body cannot do MA (500D)

You can call me slow (most do!) but that's interesting to learn. Thank you. I wasn't aware of camera bodies being able to or not able to perform micro adjustments. I will do some reading on it.

[Max]

another one to consider is the 50-500 OS Sigma lens, better IS than the above two and from the various reviews it has better IQ than the 120-400 and the 150-500.

Another option is to look at the old 400 5.6L prime. Do you really need a zoom when you already have a reasonable range with your Tamron