On Apr 28, 2005, at 5:43 PM, Christian wrote:
I've compared the Canon EF28/1.8 and EF50/1.4 against the Pentax A28/2.8 and A50/1.4.
Results: - Both Canon lenses do better at resolution and contrast wide open ... by f/5.6, differences pretty much disappear.
I'm not surprised. Actually I am. I thought the Pentax offerings would do
better than the Canons wide open.
- Both Pentax lenses do better at out of focus rendering between wide open and two stops down in my opinion, although the Canon lenses certainly do well too.
Both 50s are good if not great lenses. I have no experience with either
28s.
Between the two 50mm lenses, it's very very close. Rendering is the key ... and there the Pentax is well ahead of the Canon. I consider the Pentax A50/1.4 to be one of the best 50mm lenses I've ever used, compared even to the Leica Summicron-M and Summilux-M lenses I used to have. The Canon 50/1.4 is no slouch either, although it's not their best focusing mount (the 50 uses a USM micromotor where the 28 has the much better USM ring motor).
The 28mm lenses are a little more disparate: the Canon is clearly sharper on center wide open than the Pentax, but its corner/edge areas are softer. The Pentax is a little soft all over wide open, comparatively speaking. As they stop down, the Canon's corners tighten up to match the center; the Pentax tightens up across the board. Again, the Pentax wins on rendering performance.
All of these are judgements based on their performance with the 10D and *ist DS bodies. Performance on film often differs ... The Canon 28/1.8 has a bad rap with film SLR users for corner and edge softness. I think the even overall quality of the Pentax A28/2.8 when wide open is probably more appealing on film.
Godfrey
