This is the rather crap still life image used to test the sharpness of my screw mount standard lenses.

Helios 58mm f2

Not bad - you can easily read the writing on the deoderant can when enlarged.

Carl Zeiss Jena 50mm f2.8

Nowhere near the same resolving power as the Helios, but the strength of this lens lies in its consistency and its contrast - the Helios has awful bokeh through spherical aberrations - out of focus areas near the edges of the lens look warped - whereas the Zeiss has fairly nice bokeh right across the lens.

Yashinon 50mm f1.7

Sharper than the Zeiss Jena, not as sharp as the Helios, but overall better edge resolution than the Helios. Suffers from not being multicoated due to flare, however.

Pentacon 50mm f1.8

Not as sharp as any of the above lenses, the Pentacon does, however, give pleasantly soft images, and has, again, very nice bokeh; not stunning, but not bad.

Fujinon 55mm f1.7

As you can clearly see, this is easily the sharpest of the lenses on test, with very little bleeding of the light areas. Like the Yashinon, suffers from flare badly in bright light, but otherwise an awesome lens.

I will include a shot from my Yashinon 50mm f1.4 and from the Pentax Super-Takumar 55mm f1.8, but I can assure you that the Pentax will blow all of the above away. Sharp? My fingers nearly fell off just from handling the negatives.