17-40 L + 10-20 = redundant?

Would gettin the Sigma 10-20 be redundant?
My widest is the 17-40 L.
At 17mm, the effective FoV is 22mm which is pretty wide. Obviously im contemplating the Sigma 10-20 because its wider.

But I have two concerns.
Firstly, some online reviewers posted photos of the Sigma 10-20 using the 1dmkii and stated and posted pictures @ 11mm that poses no vignetting.

(http://www.ephotozine.​com …estdetail.cfm?t​est_id=362)

I definitely saw vignetting or dark corners at 11mm.
Can that be possible? Technically both our (ephotozine and mine) sensors should be 1.3x


Second, would it be redundant with my 17-40 L?

I'd be surprised if the 10-20 didn't break down around the corners. It only has a 27 mm diameter FoV that's guaranteed to be of any quality. Your 1D II has a diagonal of closer to 35 mm. Not something I'd want to take on. If you want wider than your 17-40, what about Sigma's 12-24, which is a FF lens, so won't be any problem with your camera.

It is most certainly not redundant. Go out and buy it.

I don't think there's any question that their 11 mm photo from the 1D II shows vignetting. You can't see a 100% crop of the corners either, so there's no way of telling how much the image degrades down there, either. I wouldn't trust it much past 15 mm, and there are FF Sigmas that will do that for you already.

Im sorry im not getting you Jon.
How come thier 11mm shot showed no vignetting but at the store today I could definitely se dark corners till 12mm.


Also, whats up with the Sigma 12-24?
I thought the 10-20 replaced the 12-24. I did not realize the latter was DG and the former DC. I guess I did not realize it because Canon did not release a FF lens(zoom) wider than 16mm, so I assumed Sigma did/could/would not.

So it would make more sense to go with the Sigma 12-24 rather than Sigma 10-20 because I would (so far) ultimately use it(10-20) at 12mm because of vignetting or rather to avoid ving.
Many reviews though say that the 10-20 has better color and is sharper. It is also cheaper than the 12-24 and faster. So now the 10-20 sounds like a better idea.
hmmm...


update:

Incidentally 12mm is the widest rectilinear lens made by anyone for full frame 35mm use.
(http://www.bobatkins.c​om …ws/wide-angle-lenses.html)

Good job Sigma.


But...

How am I supposed to use a Polarizer if I buy this lens?

Bad job Sigma?

If you mean this image there's very definite vignetting in the corners. Look at the sky. They didn't, as far as I can see, actually show any 11 mm shots on a 1D, nor did they provide any close-up looks at the corners of the pictures.

Sigma still makes the 12-24 and 15-30 DG lenses. They don't make a particular lens because Canon does, but because they think they can sell enough of it to make a profit.

Quality wise which is better?
The 12-24 or 10-20 ?

On a 1D - I'd go with the one that's designed to cover the entire sensor. As I said, once you get outside the design imaging area, the lens designers don't really care what happens to the optical properties. That's not something you're likely to see anyone testing for, however, because it's not the design sensor size for either.

thanks Jon!

I ended up gettin the 10-20. The ability to use filters (77mm) and its faster than the 12-24 helped me make my decision. Also, it was cheaper.


thanks

SoToMoSo wrote:
thanks Jon!

I ended up gettin the 10-20. The ability to use filters (77mm) and its faster than the 12-24 helped me make my decision. Also, it was cheaper.


thanks

You'll have to give us a review of it then. The 12-24 uses (much cheaper) rear gel filters. Won't let you use a polarizer, but I have serious doubts about polarizers ona wide angle lenses anyhow.

Ill do a more in depth review in a few days. But so far HSM is fast. I would say almost as fast as the bigma. Build is also similar to L lens quality. Meaning there are no loose or laggy parts. Hood fits on nice and tight.
Albeit people's complaints about stiff focusing/zooming rings. I think thats a good thing because eventually it loosens up and if it was loose or shaky to begin with , it will get very loose later.

I forgot about polarizers and wide angles.
I may have to do some testing to make sure I dont get uneven skies.