Sigma 10-20mm, Sigma 8mm or Canon EF-s 10-22mm
I am considering purchasing a fisheye or ultra-wide angle lens for my Canon 450d (from the Digital Rebel XSi kit) and I have narroed it down to these three options:
Sigma 10-20mm 4-5.6 EX DC Canon HSM ultra-wide angle lens
Sigma 8mm F3.5 EX DG Canon Circ Fisheye lens
Canon EF-s 10-22mm 3.5-4.5 USM ultra-wide angle lens
My question is what do other people think about these lenses? Are they usefull for 360x180 panoramas or do they cause some problems? What lens offers the best bang for your buck> Will they work with my 450d (I think so, but I would like confimation) How many shots around are need for 360 degrees (3 or 4 for the Sigma 8mm and 6 or 8 for the others?)? I don't intend to ever print any panos, I will just be posting them online. Also, will my setup (canon 450d with any of these lenses) fit onto the Nodal Ninja MK3. That is the pano head I have now and I am not ready to upgrade yet.
At the moment, I will not purchase anything, I am just doing research to see what is my best option. Right now I really like the Sigma 10-20mm because of the price ($700). I am only a student and I can't afford to dish out thousands for just a lens, I would rather spend the money on books for school or tuition.
Anyways, thanks in advance for any comments and suggestions. Hopefully one day I will make up my mind.