I'm looking at buying a super wide angle zoom for my Canon 10D to take interior shots. I had been looking at the Sigma 12-24mm F4-5.6 EX DG lens but held back on purchasing since they announced the 10-20mm f4-5.6 EX DC HSM. Studying the specs I have to admit I'm rather confused, I'm after the widest angle of view possible, and according to Sigmas website the 12-24 has an angle of view of 122° - 84.1°, whereas the 10-20 only has 102.4° - 63.8°. Now this doesn't make sense to me, unless it's to do with the fact that 12-24 is a full size 35mm compatible lens whilst the 10-20 is designed purely for APS sized digital. If this is the case does anyone know what angle of view I would get out of the 12-24 on an APS sized digital?
Also I know the 10-20 has not yet been released but has anyone heard any reports on it?
many thanks