I took two framings this morning. In my typical on-the-fly approach these were shot without a tripod. So I shot several of each and chose the sharpest. Roughly 1/125 @ f9. These are my blackberry bushes in the back yard.
The "scene" image represents the shot used for the center. I then shifted so that the center ended up in the lower left corner. This made for some interesting comparisons of the same elements. The "bokeh" shots came from the shifted framing and are just off-center. One technical caveat: Though I used manual mode with the green button it appears that the K55/1.8 stopped down differently. The originals were underexposed so the DOF was greater. That affected the bokeh shots. Center The K55/1.8 compares favorably with the F50/1.7. The center shots with the F50/1.7 are only slightly sharper. Not much. The K did quite well. To be a bit more precise, the leaf veins are a bit clearer in using the F50/1.7 but the small white buds appear more distinct with the K55/1.8. Of course the slight magnification advantage might help the K55 in that regard. Still, not a great deal of difference. Corner The corner shots exhibit roughly the same distinctions. Bokeh/rendering The bokeh shots are significant. The red things in the window show little separation with the F50/1.7 while the K55/1.8 shows the much more distinctly. Likewise the bushes between the windows and the house siding are very different. The one extra stop with the K lens accounts for this. Still even if one adds one stop with the F50/1.7 to create an equivalent result, the K performed quite nicely. When it comes to rendering the soft edges with the K are much smoother. The F50/1.7's edges are much softer, almost having that double-image appearance. I think the K wins in this regard. Conclusion: If you are shooting film and want a really sharp non-A lens it is hard to beat the K55/1.8. -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
