Originally posted by pathdoc 2) Will the current generation of full-frame sensors (whichever one Pentax chooses) show up imperfections in film-era lenses that film would not have?
The 'imperfections' debate throws up a number of interesting issues.
One perspective on the issue is that many of those film era lenses were not imperfect themselves, but were instead simply let down by the limitations of film - the chemistry of it, the uneven way it lay in the camera, the way it was processed and printed. Now, in the era of high resolution digital sensors, those old lenses are finally able to show their true capabilities without film getting in the way.
In evaluating old 'film era' lenses on digital we also have to note that you may now run images shot with 'imperfect' lenses through in-camera corrections, or Lightroom, PTLens, Capture One, DxO Optics Pro or other tools, and with a press of a button, vignetting, geometric distortion, CA etc can be corrected better than they could ever have been in the film processing lab. And some programs - eg DxO - might even automatically apply a touch of tailored deconvolution to sharpen up those soft edges too. So modern high-resolution systems won't reveal 'imperfections' in old glass, they may directly make even 'imperfect' old glass perform better.