Thursday, November 30, 2017

Lens Stories ~ Nikon Nikkor 28mm f/3.5 Ai

Lens Stories ~ Nikon Nikkor 28mm f/3.5 Ai

After the arrival of the 24mm Nikkor I re-realized that Photographic Tool Acquisition is a rather slippery slope.

I say re-realized because hundreds and hundreds of lenses and cameras have passed through my hands over the years.  Hundreds, I tell you.  It's either something to laugh about or to be suspicious of.  What on earth have I done with all that glass?  When I think of the beautiful pieces of gear I've owned, sometimes I nearly weep for not having kept them.

After picking up a few lenses for around 40Euros the Lens Acquisition Bug hit.  Again.  For the 'um-teenth time.  It's a recurring illness.  It's Madness.

This time the parameters of my buying and buying and buying is based on a simple principle: Find the very finest manual focus lenses I can for less than 50Euros.

Recently I've noticed that the bottom of the old lens market has started falling out.  There are some brilliant things to be had for just a few shiny pieces of silver.

My current system is built around Sony APS-C mirrorless cameras.  Manual focus lenses are fitted by way of either a Nikon to NEX straight-thru adapter or a Lens Turbo II focal reducer.

The focal reducer keeps the field of view that a lens would have on a full frame camera by reducing it to fit an APS-C sensor.  In this way I can achieve the full frame 35mm imaging "look and feel" on the smaller sensor system.  But as I've previously noted, not all lenses behave well in the corners when adapted using the Lens Turbo II.  There are limits to this Madness.

Trolling eBay point fr one day I found a 28mm Nikon Nikkor f/3.5 Ai.  It seemed to be in good condition, but folks weren't bidding much on it.  As the clock ticked down I jumped in with a rather low bid.  It stuck.  Now I'm stuck (happily, it turns out) with a 50-ishEuro lens.

I never considered the 28mm f/3.5 as it's an old old design.  It's so old that it is perhaps the first retrofocus design implemented by Nikon for the F-series SLRs.  While Nikon is proud of its achievement, I wasn't sure if it would be sharp.  The maximum aperture was rather slow, too.  A few 'netizens have suggested the f/2.8 and f/2 versions are better.

For so little money it didn't seem like it was such a bad thing to see how it worked.  If I didn't like it, I could flip it and not be out much (if anything) on the deal.  Ah, the Glories of Rationalization.

Once in hand I took a fairly close look at it.  This lens is wickedly sharp from wide open in the center.  And the corners clean up nicely by f/8 or f/11 when used with the Lens Turbo II.  It seems like it's every bit as good as a modern aspheric design lens of similar field of view that I own.  This out of lens design that dates to the late 1950's.

I like the lens well enough that it's become the primary optic for a series of images I'm currently working on.  Here's an example of what I'm doing with this sweet little optic.

Heavenly Music ~ Paris, France

Wednesday, November 29, 2017

Lens Stories ~ Nikon Nikkor 24mm f/2.8 AiS

Lens Stories ~ Nikon Nikkor 24mm f/2.8 AiS

When we moved to France I brought a number of old manual focus Nikon lenses.

One of the lenses in the batch of Fun Things was a 24mm f/2 Nikon Nikkor Ai.  I never used it and sold it.  The reason is I didn't like it.  It was soft wide open and I wasn't convinced that it could match the image quality of the inexpensive AF lenses I used at the time.

After watching a Joel Grimes portrait lighting video I saw that he used a 24mm lens to great effect.    The idea of using an old manual focus lens for portraiture was suddenly attractive.  I felt the desire to try another 24mm full frame lens.

I have two autofocus wide angle lenses that I could use but don't like using AF lenses with their manual focus function "focus by wire."  Justification and rationalizing comes easy to me.

Scanning le bon coin one day I stumbled on a 24mm f/2.8 Nikkor.  The price seemed correct when compared against eBay completed auctions.  After firing off an email to the lens' seller we made arrangements to meet so I could view the object en vente.

The Nikon Nikkor 24mm f/2.8 AiS is a pretty little thing.  It's relatively small and light for a lens that comes mounted in real metal (as opposed to plastic that tends to be used in current AF optical implementations).

The f/2.8 version of the Nikon 24mm lens is most definitely sharper and more contrasty in the center than the f/2 I sold.  But, and this is a huge "but", the corner performance suffers to the extent that it is unusable on my APS-C Sony mirrorless cameras when mated to a Lens Turbo II focal reducer.  Stopped down to f/8 and f/11 the lens never cleans up in the corners.


Mounting the 24mm Nikkor on a straight-thru adapter turns the effective focal length into a 35mm f/2.8 lens on my tiny Sony APS-C mirrorless.  This isn't exactly what I intended.  If I wanted a 35mm lens, I'd prefer to have my old Nikkor 35mm f/2 back.  I foolishly sold the 35mm when I went through a fit of "downsizing" my Collection of Photographic Tools.  Though, I suppose, I could wait until full frame Sony mirrorless prices descend from un-obtainable to somewhat affordable and use the 24mm lens on that.  Someday.  Maybe.

I feel "stuck."  Again.  This is a lens I really want to love.  Yet, here is another 24mm Nikkor that, for one reason or another, I can't use as I intended.

Sunday, November 26, 2017

When everything conspires to succeed...

My father and brother were scheduled to come to Europe on vacation.  Unfortunately my father broke a leg as he was "buttoning up" his home before the trip and they couldn't come.

My wife and I were left with train tickets and hotel reservations to deal with.  We canceled what we could, but we prepaid several things we couldn't back out of.  So we decided to use what we'd already paid for.

Our destination was the beautiful town of St. Malo which is out on the western edge of France in celtic Bretagne.  We'd been there once before, but I was sick that time and wasn't able to fully enjoy the adventure.

It'd been over a year since I'd acquired my French driver's license, so we decided to test it out by renting a car.  Usually we take public transportation everywhere.  We get to see things in relative comfort and ease.  But renting a car would require my attention be diverted and directed in a very different and stressful way.

The day after we arrived we set off for Dinan.  It's an incredible little village that still retains much of its medieval character.  The next day we visited the nearby town of Dinard.  It's a place rich in big old houses that the rich built to create a seaside playground for themselves.  On our final full day, we drove to Mont Saint Michel.

The old monastery is well known for the way it sits on top of a granite rock island.  Iconic photos of place at dusk or sunrise are easily found all over the internet.  Our visit was in broad daylight and I hoped to find a way to share a different perspective of the place since we'd be lacking the drama of the edges of the day kind of light.

Once inside the cathedral at the top of the hill I saw the windows were ablaze with sunlight.  Standing toward the back I took a series of images in the hopes of stitching them together later.  Unable to see the final result in-camera and on-site reminded me of the many years I shot film.  I would have to wait to see if what I saw and felt had been adequately captured.

Once home I opened Capture One and worked on the cathedral images.  I tried to match the exposures and curves between each of the image segments.  I've found taking care of such things sometimes helps in the stitching step.  Files were written out as 8 bit TIFFs and opened in Hugin.

Hugin is an open source image stitching and alignment software.  I recently experienced several failures using Hugin in that it doesn't always align all elements of a scene correctly.  So you can imagine my surprise when the resultant file from Mont St. Michel turned out to be perfectly aligned across the entire file from the very first stitching attempt.

Next I opened the Gimp (another open source software and one that I've been using for over a decade), added a little vignetting, and lightly modified the luminosity of various regions.  As I wrote the final image out to a new file I realized the long dimension was well over 12,000 pixels.  There is a lot of useful and beautiful information in the image.

I feel I have successfully captured something unique.  No, it's not the iconic view of the medieval community, but it is uniquely mine, what I saw, and I think it's beautiful.

Mont Saint Michel ~ France ~ 2017

Friday, November 24, 2017

Other Optical Properties ~ contrast between new and old lenses

There is, of course, much more to lenses in photography than just resolution (what we usually call "sharpness").  I've spent many many blog posts sharing what I've found in that regard.  It is time to look at a different aspect of optics, cameras, and photography as tools.

Recently I've taken to working with Nikon lenses that in some cases are more than 50 years old. The resolution of the lenses match that of my modern lenses.  They are all manual focus and change my approach to image making by slowing me down.  After seeing some initial images, I was thrilled.

Without any direct evidence I felt the old Nikkors were more "contrasty".  Again without any direct evidence and without understanding how such a thing could be possible I felt that new lenses somehow gave lower overall "contrast" but better "micro-contrast" than the old optics.

Thinking about this a bit, I devised a small comparison.  Here is what I did.

I photographed the same scene with matching in-camera cropping using new and old lenses.  Then I found a way to overlay the RGB/Luminosity "curves" to  compare how lenses handled the light range.

The lenses I looked at were -
  • Sigma 19mm f/2.8 EX DN
  • Sigma 30mm f/2.8 EX DN
  • Sony 50mm f/1.8 SEL OSS
  • Nikon Nikkor 24mm f/2.8 AiS
  • Nikon Nikkor 28mm f/3.5 Ai + Lens Turbo II
  • Nikon Nikkor 50mm f/1.8 AiS + Lens Turbo II
  • Nikon Nikkor 105mm f/2.5 Ai + Lens Turbo II
All lenses were shot at f/5.6.

After photographing the scene I found I needed to match where the top and bottom of the "curve" touched the data recorded by the camera.  I needed to do this because the exposure system in the camera never exactly matched lens to lens, frame to frame.  This step is also rather important to my understanding of what's going on, as we will soon see.

Here are the results -

Curves Overlays ~ various lenses

Curves Overlays ~ various lenses

Curves Overlays ~ various lenses

To begin with, the old manual focus lenses seem to in general place image information slightly lower than modern optics.  The highlight and shadow peaks are consistently behind where the new Sigma and Sony lenses place them.  Could the be an effect of the camera system taking a slightly different path to calculating exposure?  Instead of balancing aperture, shutter speed and ISO, with manual focus lenses only the shutter speed and ISO are directly controllable by the system.

Additionally, I see is that with the shorter focal length lenses there is a slight difference in how the highlights are rendered.  The highlight portion of the curve is broader with the new Sigmas than it is with the old Nikkors.  The longer lenses, on the other hand, appear to have nearly identically shaped curves.  Are the differences in curve shape in the highlights due to optical properties or by the way the camera system, again, calculates exposure by moving the highlight peak up the curve and thereby "spreading" the peak?

Then when I think about how I generated these illustrations in the first place (trying my best to match where the tops and bottoms of the curve first encountered recorded information).  I quickly understand that it is entirely possible to more precisely match the shapes of the curves between any of the lenses.

Even without answering my questions about how the Sony NEX/Alpha cameras calculate exposure with fully automated and old manual no-aperture controlled lenses, I think I can safely share an interesting outcome of little comparison:  After processing there is no meaningful difference in how new and old optics send light to a sensor.  Said another way, in terms of "curves" shape I feel it is very likely possible to make a new lens "look" like and "old" one, and vice versa.

As for what started me down this path, that the old Nikon Nikkor lenses were more "contrasty" than modern optics, and that modern optics were somehow better able to render "micro-contrast", I see no evidence to support my feelings and earlier thoughts.

This is why I take the time to look at these kinds of things.  I learn something nearly every time I take a deeper look at photographic tools.