Unfortunately i can only buy ONE because i sold everything i had to afford the 5d!
I`m stuck between a Sigma 50mm 1.4 and a Canon 85mm 1.8.
If you have already narrowed down your options between Sigma 50 or Canon 85, I'd say Canon EF 85 f/1.8
Why? 5D MK II (although a great camera) is not really known for it AF system, so pairing it with a third party (Sigma) lens, as your only lens, could end up being a bad decision due to potential
front focus/back focus issues ... hence having a Canon lens paired with a Canon camera makes better sense especially when it is your only lens. Don't get me wrong, I personally have used many third party lenses (mostly Sigma ... in fact there was a point in time when I had more Sigma lenses than any other maker's) and I still have 2 third party lenses (Sigma 150-500 OS & Tamron 24-70 f/2.8 VC) but I found & continue to see that the equivalent Canon lens work better with a Canon Camera than any third party lens I used or have. But if 50mm is what you'd like to have (which is a better focal length as the first lens than 85mm) go for Canon 50 f/1.4
BTW just yesterday, I ordered Canon EF 85mm f/1.8 from B&H (got a really good deal) ... expected to arrive this coming Thursday.
« Last Edit: February 19, 2013, 12:21:01 PM by Rienzphotoz »
5D MK III, 16-35/2.8 L II, 24-70/2.8 VC, 24-105/4 L IS, 70-200/2.8 L IS II, 100/2.8 L IS, 40/2.8, 50/1.4, 85/1.8, 150-500 OS, 600EX-RTx2, ST-E3-RT, Rokinon 24/3.5 T-S, D7100+18-300 VR, YN568EX, 055CXPRO4+468MGRC2, 190CXPRO4+322RC2, Gorillapod Focus+496RC2, CamRanger, B+W filters, Konova K3/31.5 etc