Canon 100-400L vs Sigma 170-500

[Homer]

Has anyone else compared the Sigma 170-500 against the Canon 100-400L?
I've been going through the forum and it seems everyone loves their Canon 100-400L for wildlife photography. I was just about ready to buy one to replace my Sigma 170-500 which I have had for a number of years. It doesn't have teh greatest reputation, especially compared to teh 100-400. I decided to rent it for a day just to try it out and it does feels great on a 20D. I took a few test shots to compare to my Sigma and was really surprised when my Sigma gave comparable results and in some circumstances was even sharper like in the shots below.
The two goose pictures are taken a few minutes a part both at ISO 200 F5.6 1/1600s
First one is with the Canon and second is with the Sigma. Both pictures are untouched except for resizing. The recorded focal point for both was on the body of the bird.
The shots I've seen on the forum with the Canon are always super sharp, so I'm just wondering if I got a not so great copy, or is my Sigma fairly decent after all, even when compared to L glass. Does anyone have any comments or experience with both of these lenses??

Thanks

[CyberDyneSystems]

I can't argue with your examples,. the second image is much better and clearer...

[condyk]

To my eye the Sigma is super sharp around the head ... like night and day compared to the Canon. I assume you took several pictures with each to make sure it wasn't just a bad shot with the Canon.

[HKFEVER]

The first picture has focusing problem, you can see the water in front of the bird is very sharp.:D

[Homer]

Condyk, Yes, I took about 5 or 6 shots with each lense and most of them were pretty similar

HKFEVER, You're right, the water in front seems much sharper but the focus points that register were all on the body.. The goose is a bit further away on the Canon shot, depth of field would be a little less

[HKFEVER]

If I were you:

- Have some more test shoots under control conditions.
- If same thing happens, then return the rental and try to get another one for test again.

I think, either you have shift the FP when you release the shutter, the lens is front focus or something else.

I am pretty sure that lens is shape...

[robertwgross]

I've been there and done that. Sigma lost out to Canon. Granted, Canon is shorter in focal length, but the Canon lens will accept one 1.4 TC and remain sharp enough. Sigma gets mushy quicker. In fact, often I use the Canon lens with two 1.4 TCs, and it can still remain sharp enough. Sigma was too mushy by that point.

---Bob Gross---

[goldstrikn]

Can't argue with those results. Sigma looks good.

[Bushman]

Isn't the canon 100-400 a push/pull zoom? I would think that would aggrevate dust getting in the camera body and then the sensor.

[CyberDyneSystems]

Bushman:
Yes it's push pull,. no it deos not seem to aggrevate dust any more than with other lenses.

I too have done the Sigma Vs. Canon comparison,. I had the Sigma 50-500mm though,. but most will argue it is the superior of the two Sigma's...

The canon won out in all aspects other than the 100mm at the long end,. and focus tracking wth smaller objects.

I can definitely get sharper images with the 100-400mm than the one displayed here. I wonder what the cause of the blur is,.. coud be lots of things.

[Croasdail]

It also seems the canon is lacking a little in contrast - if you compare the blacks. Sigma seems acceptable to me.

[rebel61021]

I have both and the only reason I got the canon 100-400 was for the IS I still use my sigma when I am shooting with the tri-pod just for that little extra reach I love the pictures that the sigma takes and would have a hard time telling them apart if I did not take them. The biggest advantage is being able to hand hold the 100-400 f4L IS. and still get great shoots

[greyson08]

hmmm either way, the sigma looks good, no?

[foxbat]

Looks like you got a great copy of the Sigma. If I were you I'd be questioning what problem I'm considering spending many hundreds of dollars trying to correct. From these images I can see that your Sigma focus's well, produces very good contrast (feathers on the goose back) and has 100mm in reserve to spare.

[ScottE]

I compared the Sigma 50-500 and Canon 100-400. On the two lenses I compared the Sigma had slightly better resolution, but no where earo the difference shown in the two pictures posted. There really wasn't enough difference that you would choose one over the other based only on resolution.

Having seen many pictures taken with the 100-400 I don't think the picture posted is typical of its ability. There may have been a problem with focus, camera movement or subject movement.

[TTP]

The second photo is certainly amazing!

[Az2Africa]

Great shots either way. I noticed it was two different ducks. Maybe one was more photogenic than the other!He He:)

[Homer]

rebel, its great to hear that from someone who actually owns both lenses. The IS on that Canon is definitely a beautiful feature, but compared to the price of that lens (oh but it does look so good attached to that 20D.. something about those white lenses..) I think I can live with using a monopod or tripod when needed.

[MarkH]

Have you considered the Canon 70-200 f2.8L IS lens? It would give you a nice big white lens to put on your camera and give you the low light performance that you wont get near with your current lens or the 100-400. Since you already have a good sharp lens for 170-500 then the 70-200 would add more range at the wide end and give you a nice sharp IS lens.

You need something to spend the money on if you aren't going to buy the 100-400 don't you?

Just a thought.

[raylks]

The Sigma's is great. But you may shoot more to validate the result.

[Fer]

That second image is great!.

I was doubting on which lens would be better, sigma or canon (I haven't bought any yet) but with this example and the price of the sigma, I think I am going to get that one.