Friday, December 22, 2017

Big Comparison ~ 50mm to 210mm Sony, Nikon fixed and zoom lenses

Out of curiosity I went back and looked at the first year a friend and I copyrighted our look at the resolution of large format film lenses.  It turns out that it's been exactly 20 years.

I'm not sure this would qualify as a celebration or not, but here is my latest Fit of Curiosity and Insanity.  I wanted to see how several zoom lenses stacked up against fixed focal length optics from the same manufacturer.  Legend has it that zooms are less sharp than fixed focal length lenses.  This comparison would give me a chance to check reality against legend.

The setup -

  • Sony A6000, 100ISO, AWR converted in Sony's software 
  • Big Beefy Manfrotto tripod 
  • Sony 50mm f/1.8 SEL OSS as the control optic - this lens is amazing in every respect
  • Old Nikon manual focus lenses 
    • Nikkor 85mm f/1.8 K pre-Ai
    • Nikkor 105mm f/2.5 Ai
    • Nikkor 135mm f/2.8 Q Ai
    • Nikkor 135mm f/3.5 AiS
    • E-series 75-150mm f/3.5 at
      • 75mm
      • 105mm
      • 135mm
    • Nikkor 80-200mm f/4.5 N Ai at
      • 80mm
      • 105mm
      • 135mm
      • 200mm
    • Zhongyi Lens Turbo II focal reducer used on all Nikon lenses
The results -

If you click on the image it'll take you to the Flickr hosting site.  Once there you and look at the file at full resolution.  In many cases the differences between lenses is small and likely can't be seen until you take a squint at the image at 100 percent.

Nikom Tele Fixed and Zoom Comparison

My observations -

The Sony 50mm f/1.8 SEL OSS acted as my control lens for this comparison.  It's every bit as good as the Sigma 60mm f/2.8 Art DN I once owned, and perhaps a bit better.  In the area of out of focus rendition this Sony is brilliant where the Sigma was a bit harsh.  In terms of resolution I really can't tell any difference between the two lenses.

The fixed focal length Nikkors mated to the Lens Turbo II are all similarly sharp in the center of the frame from f/2.8 down thru the f-stop range.  In the cases where the extreme edges of the frame are just a tiny bit soft, they clean up nicely around f/4.

Looking at the zoom lenses and starting with the super cheap unloved E-series 75-150mm f/3.5 constant aperture, I came across something of a surprise.  Wide open at anything less than 135mm this lens is as sharp in the center as fixed focal length equivalents.  The edges, however, can be a bit soft.  However, even the edges clean up nicely by f/5.6 at the shorter focal lengths.  As a bonus, this lens came to me for around 40Euro.

Moving on to the Nikkor 80-200mm f/4.5 N Ai and again looking at the center resolution from wide open, this zoom appears to match the fixed focal length lenses between 80mm and 135mm.  At 200mm the lens is ever so slightly softer than the fixed length objectives.

Looking at the extreme edges of the frame, I should note that with this series zoom (I've owned two of them at the same time) shows a fairly big drop in resolution.  If you must have the edges perfectly sharp to the utter and very edge it's best to either slightly crop your zoom lens images or use a fixed focal length lens.  In general longer focal lengths are softer.

I would like to make a couple special notes.  The Sony 50mm f/1.8 is obviously brilliant and the prices on these are rather attractive.  If you shoot Sony APS-C mirrorless and like taking portraits or using a focal length slightly longer than "normal", I'd say this lens is a "must have."

The Nikkor 135mm f/2.8 is a beastly heavy optic for its focal length, but it's sharp from wide open.  I didn't expect the old design Q-series Ai to perform this well, but it does.  The out of focus rendition isn't half bad, either.  The prices on these are good if you shop carefully.  I've seen them trade hands for around 60Euro.

Lastly, I need to mention the Nikkor 135mm f/3.5 Ai.  The effect is subtle and you might not recognize it from the 2D newspaper shots I use when comparing various lenses, but the contrast and resolution of this lens is nothing short of phenomenal.  It "feels" very much like the brilliant Sigma 60mm Art DN and Sony 50mm f/1.8 SEL OSS.  If any lens has a dash of magic, this one definitely has it.  I find this little lens to be wickedly awesome.

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