I also have no doubt that the DA is the 'better' lens. Inspecting 100% crops on computer screens however isn't really what lenses are made for. I do not say that this makes no sense, but it should be put into context. If stopped down to 8 or 11 the Sigma is good enough to produce 15x20" prints of very acceptable quality (to me). Would you really say that print quality is much different between both lenses?
Regards, Sven -----Ursprungliche Nachricht----- Von: Joseph Tainter [mailto:[EMAIL PROTECTED] Gesendet: Sonntag, 3. April 2005 00:51 An: pdml Betreff: DA 14 vs. Sigma 12-24 Having time today I decided to test the DA 14 f2.8 against the Sigma 12-24 f4.5-5.6 DG at 14 mm. I did this in part to clarify in my own mind what is going on when people complain about the DA 14 being weak in the corners. I know, I know -- I am comparing a prime to a zoom. No contest, right? Well, the Sigma is the only lens I have access to that includes the 14 mm. focal length. Also, the last time I compared a prime to a zoom, it was the DA 14 vs. the DA 16-45 at 16 mm. -- and the zoom won. The subject was, as usual, an adobe (mud brick) wall, with the camera at about one meter distant. I used ISO 200, and a tripod. All comparisons were at actual pixels, although I went to 200% in one case. Firstly, the DA 14 becomes progressively sharper through f8 (the smallest aperture I tested). The center is noticeably better at f4. At f5.6 the corners sharpen up considerably, then improve a bit more at f8. Stop this lens down. Now the comparison. Both lenses wide open: (f2.8 for the DA 14, f4.5 for the Sigma). The DA 14 is much sharper in the center. It is mostly sharper also at the edges and in the corners, although the difference is less. The Sigma may be slightly better at the left edge and in the lower left corner. Where the Sigma seems better, it is not by much. Where the Pentax is better, the difference is very clear. F5.6 (both lenses): The Pentax is far better in the center, slightly better at the edges and in the corners. F8 (both lenses): The DA 14 is much better in the center and corners. It is also better at most edges, the exception being the left edge where the Sigma seems a bit sharper. The DA 14 is clearly the better lens overall. What is interesting is that it has an arc of slight weakness from the lower left corner to the left edge (about 225 to 275 degrees). Shouldn't lens performance be symmetrical? I would think that even assymetrical lenses should be symmetrically assymetrical. Any thoughts? BTW, on aperture priority the Sigma consistently exposed the images 1 EV less than the DA 14. The Sigma seemed to be underexposing. Joe ----- Ende der weitergeleiteten Nachricht -----
