Rokkor Duels

I shoot with all manual lenses.  The moment I purchased my GH2 I decided to get old film lenses and save money on glass.  Yet as my personal obsession with lenses has grown, I doubt I've saved much money in the long run.  I'm becoming fascinated with lenses and how they affect the picture, how one lens can make the picture look flat and the other render everything sharp with great contrast.  As my eye becomes more refined I'm able to notice these subtle differences in picture output.  So I have decided to use my newly refined senses to determine the better of two lenses.  Through my unhealthy lens hoarding I have acquired a Rokkor-X 50mm 1.4 Minolta MD as well as a Rokkor-PF 58mm 1.4 which is a Minolta MC I believe.

Build Quality
Of the two, I prefer the build quality of the R58 over the R50.  I looks more vintage (which it is).  It's larger and heavier than the R50.  It feels like a tank, gives off this air of "this lens is important."  It has eight iris blades as opposed to the R50's six.  They don't necessarily make an octagon shape, though.  It's a bit more circular.  The iris blades on the 50mm maintain a perfect hexagon shape throughout.  So the first decision factor between the two would be to choose between hexagonal or circular bokeh.  Both of them range from 1.4-16; however, one plus for the R50 is that it stops up in half stops.  So it provides more variance of light, which is pretty sweet.  I had to admire it for that.

Now this test wasn't completely fair because I remembered only just now that I had an FD filter on the R58.  What affect that had on image quality I have no idea.  This was the optical performance test.  I looked at sharpness, and bokeh.  Though I could rate color definition and contrast, I was filming on my custom flat setting, so it's not fair to judge either of these.  However, if I were to make a selection I would say the R50 does a better job in color and contrast.  The 58mm just looked more flat.  But if my intention when shooting is to shoot flat, is that really a bad thing?

Sharpness
This ought to be obvious from the video but I'll go ahead and throw my opinion around anyway.  I mean, it's my blog, dammit.  The R50 is much sharper wide open than the R58.  It picks up a lot more detail.  Wide open, the R58 is very soft and dreamy.  Could be a useful aesthetic choice for portraiture.  Yet at f2.8 the R58 becomes EXTREMELY sharp.  I feel it surpasses the R50 in sharpness at this aperture.  I only tested up to f/4 because that's about the extent of my aperture flexibility.  I really enjoy narrow depth of field.  Plus due to the new hack the camera stopped recording at 5.6 so I figured I'd change lenses if I already had to take the camera off the tripod to pop out the battery.

Bokeh
The R58 produces a smooth and circular pattern.  In comparison the R50 seems harsh, like theres more going on.  It has definite hexagon shapes and detailed bokeh patterns.  Not sure which I prefer though.  This would also depend on the project and which lenses I were to be using them with.

Conclusion
I hadn't mentioned this earlier but didn't create a category for it so I'll mention it now.  The R50 has a greater focal depth.  You can focus on objects a few inches closer than you are able to with the R58.  At the moment... I can't pick a winner here.  I was leaning towards the R50, but the more I look back at the sharpness of the R58 at 2.8 and on, it's very impressive.  I like the dynamic of the lens, being so soft at wider apertures and sharp as a knife at 2.8, which is still fairly open.  You can expect more tests coming soon.  I need to settle this fight somehow.