Thursday, January 04, 2018

Comparison ~ Nikon Nikkor 300mm, 135mm, 105mm + Lens Turbo II

Continuing to troll the 'net for 50Euro or less highest quality lenses yielded up a Few More Fun Things.

Last year I sold a mint 300mm Nikon Nikkor f/4.5 pre-Ai lens.  Of course I started to regret the sale.  It was a really nice, sharp optic.  So when another came available at half the cost of the first 300mm, I jumped at it.

What I now have is an excellent condition 300mm lens that dates even earlier than my first example.  The focusing collar is smooth and accurate (nearly Super-Takumar-like in this respect, which is a surprise for such an old Nikkor).  The exterior condition is excellent.  But the front element has a few cleaning marks.  They are very light, very fine marks, but, neurotic as I am about such things, I know they are there.  I may learn to live with it.

The setup -
  • Sony A6000, 100ISO, AWR converted in Sony's software 
  • Big Beefy Manfrotto tripod 
  • Nikon Nikkor 
    • 300mm f/4.5 pre-Ai (c.1971)
    • 135mm f/3.5 Ai
    • 105mm f/2.5 Ai
    • all mounted on a Lens Turbo II focal length reducer
  • One pass where 300mm f/4.5 images were processed
    • Gimp -> FX Foundry Luminosity Sharpen
    • Gimp -> Curves (subtle adjustments to tonal range)
The results -

Here is the scene setup -

Scene Setup Nikkor 300mm, 135mm, 105mm comparison

Here are 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.]

Nikon Nikkor 300mm, 135mm, 105mm Comparison

My observations -

The Nikon Nikkor 300mm f/4.5 pre-Ai stands up rather well against the wickedly sharp 135mm f/3.5 Ai.

Wide open the 300mm shows softness that typically comes from spherical aberrations.  You can see the effect around the large lettering.  One stop down and the 300mm seems to match the shorter focal length lenses across the field.

The 105mm f/2.5 Ai suffers at f/4 and a little at f/5.6 in the corners.  I think it is an effect of field curvature, particularly when the lens is used with the Lens Turbo II focal reducer.  I've seen similar things when making these kinds of 2D flat sheets of newsprint comparisons between various lenses.  I've specifically seen the effect with the 85mm "K" pre-Ai Nikkor, Lens Turbo II combination.

My comparisons are always made using un-altered, straight off the sensor images.  I convert AWR files using Sony's conversion software and I leave that software with it's default settings.  I never add nor subtract, for instance, "sharpness" nor contrast.

With this comparison I added a line where I took the 300mm Nikkor images and passed them through the Gimp and two functions.  Specifically, I passed the images through FX Foundry's Luminosity Sharpen and used "Curves" to try and match the tonal range of the 135mm f/3.5 images.

Luminosity Sharpen is a very subtle sharpener.  I think it's better than many "smart" sharpen algorithms in that Luminosity lightly touches the light/dark transitions and leaves the smooth areas alone.  Images don't typically look hard sharpened when I use this function.

What I find is that lightly processing the 300mm f/4.5 wide open image yields results that appear to match the wickedly sharp 135mm straight off the sensor results.  Carefully using "Curves" I was even able to reduce the effects of spherical aberration (look at the large lettering).  At f/5.6 and f/8 the 300mm lightly processed image results appear to as "sharp" as anything in this comparison.

The "sharpening" aspect of the processing is to carefully increase transitional zone contrast.  The human eye perceives this as "sharpness".   This means that just about any file made with a well designed and constructed optical system can be carefully "sharpened" to the point that the results appear sharper than the off the sensor originals.

While there is nothing new in recognizing the effects of "smart" sharpen functions, what I find interesting and promising is that in using these controls, I might be able to use this Nikon Nikkor 300mm f/4.5 pre-Ai for photographing motorsports and birds and exceed the results I used to obtain from my old Canon 7D, 100-400mm zoom kit.

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