I have bought a Canon 5D and want a wide-angle lens?

[dogbert]

17 mm on the 5D corresponds approximately to about 10 mm on an APS sensor. So the 17-40 would be a better replacement for the 10-22 than the 12-24.

 

Having owned the 12-24, I can say it was fun to play around with on a FF but I found it hard to get interesting compositions below about 16 mm anyway (it is simply too wide for me). It also lacked some sharpness relative other lenses I have used. It was also painful to use with filters.

[mark_chappell]

<I>Okay Chaps, is it the Sigma 12-24mm or the canon 17-40mm F4 L lens?</i><P>

 

I have both, and like them both. Some comments: You cannot use front filters on the

12-24 on a full-frame camera. With the 17-40, you can, but with some limits. For

example, my Cokin one-slot filter holder will vignette below about 20 mm (still extremely

useful for grad ND filters).<P>

 

I don't have a full-frame digital, but I tried both lenses on a 5D once. Although they

produce fine sharpness on a 1.3 X camera (1DII), corner performance with the 5D was

disappointing. Somewhat better with the 17-40 at 17 mm than for the 12-24 at 12mm;

given the different focal lengths it was not a direct comparison, but the 17-40 seemed

better even when the Sigma was zoomed to about 17mm.<P>

 

The 12-24 is slower than the 17-40, but is remarkably free from distortion. On the other

hand, the 17-40 shows small but obvious barrel distortion at the short end of the zoom

range, which makes it problematic for photographing anything where you want to render

straight lines without distortion.<P>

 

Finally, it's quite subjective and correctable in photoshop, but I like the colors rendered by

the 17-40 better than those produced by the Sigma lens.

[shadowcatcher]

Thanks Prof, nice portfolio by the way.

 

I really liked the wide-angle pictures that I could get with the ef-s 10-22mm at 10mm and I was just wondering whether at 17mm, with a full frame camera such as the 5d, I could still achieve this? Is that 1mm such a big difference (16 mm equivalent vs 17mm)?

 

What I really would like to know is will I be missing things that the wider-angle Sigma 12-24mm lens could provide and are its limitations mentioned above recoverable within PhotoshopCS i.e. poorer colours, not as sharp as the 17-40mm L series lens?

 

I really appreciate the experience and opinion of those wiser than me.

 

Many thanks,

 

Kev

[dogbert]

I found the colour and contrast of the Sigma 12-24 to be fine. Sigma lenses tend to have a slightly warmer cast than canon, but the difference is not great and can be corrected in PS. The Sigma's sharpness was ok when printing up to about 8x10, no worse than the kit 18-55 (at the 18 mm end), which everyone thinks is quite good for its price. It is definitely less sharp than the sigma 18-50 EX and 10-22.

 

As I said , I found it harder to compose at 12 mm and at that width it becomes a bit of a specialty lens, whereas I could take shots all day at 16 mm.

 

In the end it boils down to your need for quality. If you want to produce gallery sized prints, the sigma 12-24 is probably not the lens for you. But I think if you are going beyond A3 you would be better of with a medium or large format camera anyway.

 

The difficulty of using filters was also a problem with the sigma. I tend to use NDs to to get water motion blur and not being able to do this with the sigma was a problem.

[shadowcatcher]

So the Sigma 10-20 mm is better/sharper than the 12-24 mm - however it doesn't fit my Canon 5d?

 

I am even more confused than ever!

 

Many thanks

 

Kev

[dogbert]

Yes, the simga 10-20 is better and sharper and it does not fit your camera. The Sigma 12-24 is in a class of its own being the widest FF lens by far. Given its width and that it is full frame, it is not really comparable to any other lens.

 

People citizise it, but Sigma did a fantastic job in making a good lens wider than anything Canon or Nikon make for less than half the price. Nonetheless the fact that it was built to a price does show, when comparing it to lenses that face less of a design challenge.