Originally posted by smc
I can understand, but some of them are very special. There are a number of factors at play. Will the lenses of today such as a 16-50 hold there value as compared to some of the Ks? It is hard to find a K28/2 which will impact cost. Ironically, the K28/2, while stellar wide open, is monumentally sharp at F16 (and from one site performs better than the 43 Ltd).
------- ... f2.0 ... f2.8 ... f5.6 . f16.... f22
28/2.0 ... 69 ..... 69 .... 78 .... 98 .... 78
43/1.9 ... 55 ..... 69 .... 98 .... 87 .... 87
$600 (or less) for a lens that sometimes outperforms a FA Ltd isn't so bad is it?
And K28/2.0 versus FA31/1.8? I don't imagine K28/2.0 would fare badly, really. (My impression is that the hype surrounding FA31/1.8 is very much fed by an insufficient knowledge of the older mf lenses.)
To come back to the issue of K28/2.0 versus K30/2.8, I did a few comparisons which may interest the K-Club members. First, a comparison of (from left to right) K28/2.0, K30/2.8 and K28/3.5 at f5.6 (100% center crop, iso 200, tripod-mounted; the object is an empty glass at half a meter distance).
The differences in this context (stopped down, foreground focus, center of the image) are negligeable. With background focus on the same scene, however, K28/3.5 loses in sharpness compared to the other two.
Limiting further comparisons to K28/2.0 and K30/2.8, my impression is that K28/2.0 has a slight edge in rendering colors and textures (picture taken at f2.8):
... and (off-center in the same picture) has slightly smoother bokeh:
So, all in all, I find evidence for Phil's ordering: K28/2.0 > K30/2.8 > K28/3.5. Is it interesting to have either K28/2.0 or K30/2.8 next to (or instead of) K28/3.5? I would say so, yes.
At the same time, to take up Lars's point: should one then opt for K28/2.0 rather than K30/2.8? Not necessarily, I would say: K28/2.0 is twice the size, twice the weight and twice the price of K30/2.8, but the image quality obviously doesn't increase accordingly. Be happy if you can find and afford a K28/2.0, but don't feel unhappy if you cannot.
Cheers,
Dirk