Monday, June 16, 2025

Chateau de Pierrefonds ~ a Digital Zone System Black and White adventure II

After reviewing my Vienna in-camera generated jpgs I went in search of a way to further refine my understanding of what is possible using Sony mirrorless cameras.  In this case I wanted to find a way to "brighten up" the highlights while keeping a sense of open shadows.

Château de Pierrefonds, France ~ 2025 

Sony A6000, Sigma 30mm f/2.8 EX DN E

  

Normally Sony Creative Style Black and White with Contrast set to 0 (default) pushes the dark values down too low for my tastes.  This is why I'd chosen Contrast = -3 for the trip to Vienna.  The highlights weren't "blown out" and the darks didn't sink into "inky yuck."  Yet the images felt that in some cases they could use a slightly different tonal range to more exactly match what I was looking for.

Keep in mind that I come from large format film days.  120 format was miniature.  35mm nearly Minox.  4x5inch sheet film was "normal."  8x10inch was glorious.  and 12x20inch film was almost "over the top."  In all cases I worked to keep a sense of "open shadows" and found processing/printing techniques to make 120 film format and larger "work" in this way. 

Château de Pierrefonds, France ~ 2025 

Sony NEX-7, Sigma 19mm f/2.8 EX DN E

  

I'm not sure how I got to asking the question, but I found myself trying to understand Sony's "Dynamic Range Optimization" feature.  It's something I've avoided using because I didn't understand it and because images I've made using DRO had too much of an HDR "look" to them. 

Considering the feature a little differently I learned that DRO levels are selectable (not just automatic as I'd wrongly assumed) with the intention of "opening up the shadow areas."  This was exactly what was desired.  So I performed a number of "characterizations" using the Sony Creative Style Black and White, setting contrast levels, and selecting specific DRO settings (avoiding DRO automation).

Château de Pierrefonds, France ~ 2025 

Sony NEX-7, Sigma 19mm f/2.8 EX DN E

  

Here's something that I found supremely useful for generating in-camera jpgs in a black and white style I like. 

  • Creative Style - Black and White
    • Contrast 0
    • Sharpness -3 (more about this below)
    • DRO 1 enabled <- this is the trick right here 
  • Expose -
    • Meter = Spot
    • Back-button AEL - Auto-Exposure Lock 
    • +2.7EV bright light areas (for 80% of the images I took) ... 
      or...
    • -2.3EV shadows (for photographing dark places - cathedral, tombs)
    • +/-0.3EV bracket for 3 exposures
  •  Technique -
    • Bright/Normal situations - 
      • +2.7EV exposure compensation (depending on how much texture I want to retain - remember Zone 8 / +3EV is "very light with a hint of texture" (edited 17 June 2025)
      • AEL the lightest area of a scene
      • Recompose
      • Release the shutter
      • Let the lower tones render as they will 
    • Dark situations -
      • -2.3EV exposure compensation
      • AEL area to be expressed as Zone 3
      • Recompose
      • Release the shutter 
      • Let the lighter tones render as they will
  • Digital Zone System details -
    • Zone 9 1/2 becomes pure white when using DRO 1
      • In fact, +3.7EV is the precise point where we go from luminescence value 247 (usable information in white) to 255 (pure white) at +4EV on Sony from NEX7 mirrorless model on...
    • Zones less than 3 often contain useful information (delivering that sense of "open shadows") 
Château de Pierrefonds, France ~ 2025 
 
Sony A6000, Sigma 30mm f/2.8 EX DN E
  
 
NOTE 1: DRO 1 raises Zone 5/0EV by exactly 0.3EV.  Zone 5 at -0.3EV is needed to compensate for the DRO 1 effect.
 
NOTE 2: Setting Zone 5 at -0.3EV when using DRO 1 expands the lightest Zones by 0.3EV.  Zone 9 1/3 / +4EV becomes pure white and thereby inching into Zone 10 film-era pure white definitions - in camera (edited 17 June, 2025)
 
NOTE 3: I find that _if_ I have time to properly meter a scene and find I need more contrast (due to a "flat" scene) that increasing this value in Creative Style Black and White brings the black point "in" and isn't all that "harsh" on the highlights (which I like to protect at the expense of the blacks if "push comes to shove").
 
NOTE 4: I like to use +/-0.3EV exposure bracketing since I seldom (or better said: never) have the time to fully meter a scene before hitting the shutter release and moving on to the "next thing."  
 
NOTE 5: Having a copy of the RAW output allows me to re-process images later, particularly if the in-camera generated jpg "isn't quite right."  Shooting RAW+jpg tends to chew up memory, but SD cards are cheap these days so I don't worry too much about it.
 
NOTE 6: Turning down Sharpness to -3 helps retain a certain sense of balance between sharpness and large format film style "smoothness."  The images seen here had sharpness set to +1.  Even when downsizing for the 'net, something doesn't "feel" entirely correct.  Later I tested different sharpness settings and found that the APS-C Sony sensors coupled with their in-camera jpg engine create something that feels much better to my way of "seeing" when Creative Style Black and White Sharpness is set to -3.
 
 
Château de Pierrefonds, France ~ 2025 
 
Sony A6000, Sigma 30mm f/2.8 EX DN E 
  

 

Sunday, June 08, 2025

Vienna ~ a Digital Zone System Black and White adventure

We needed to "get out of Dodge" for a few days so my wife and I visited Vienna.

Wien 2025 

I wanted to post images of our wanderings in near real time.  To do that I'd need to rely on the in-camera jpg processor since there was no way I'd be taking computer while on vacation.  I wanted to be out having fun and not sitting around the apartment processing RAW images.

Further, I had in mind shooting a film simulation recipe in the "big camera" that has a nice Zeiss zoom and shoot black and white in the "small" camera that has Sigma fixed focal length lens.  Things got off to a good start, but it was a rather/shockingly/absurdly large effort to download and post both the color film simulations and anything that happened to catch my eye in black and white.  Soon I realized I was very much enjoying exploring the city in black and white and decided to post works only in this style. 

A photographer friend says  "Photography is like music. You need good instruments, good technique, and, above all, artistry. When a picture sings, you've got it right!".

Palmenhaus Wien 2025 

Looking at the shear volume of images I was trying to share, I realized I was like that annoying kid with an artless kazoo marching around making all manner of noise. There was no peace.  There was no rest.  It was somewhat difficult to get it right! in camera, but there was no stopping me once I got rolling.

*snap*click*post*whee* goes the annoying kid with an ungovernable rude kazoo

After characterizing my Sony systems to adapt the old film Zone System of exposure (see St. Ansel, Brothers M.White and P.Davis, et al) for this trip I settled on the following process.

  • Creative Style - Black and White
    • Contrast -3
    • Sharpness +1
  • Expose -
    • Meter = Spot
    • Back-button AEL - Auto-Exposure Lock 
    • +2.5EV bright highlights (for 80% of the images I took) 
    • -2EV shadows (for photographing dark places - cathedral, tombs)
    • +/-0.5EV bracket - 3 or 5 exposures
  •  Technique -
    • Light/Normal situations - 
      • +2.5EV exposure compensation
      • AEL the lightest area of a scene
      • Recompose
      • Release the shutter
      • Let the lower tones render as they will 
    • Dark situations -
      • -2EV exposure compensation
      • AEL area to be expressed as Zone 3
      • Recompose
      • Release the shutter 
      • Let the lighter tones render as they will
  • Digital Zone System details -
    • Zone 9 is pure white (this is crucial: _not_ Zone 10 as defined for film)
      • In fact, +3.7EV is the precise point where we go from luminescence value 247 (usable information in white) to 255 at +4EV (pure white) (edited 17 June 2025)
    • Zones less than 3 often contain useful information (where film seldom ever did) 

Domkirche St. Stephan Wien 2025 

What I ended up with were minimally three exposures per image with 3 or 5 jpgs to choose from and post while on the road and 3 or 5 RAW to work on at my leisure after I returned home.  I "copped out" by bracketing because I seldom had the time to carefully meter a scene.  So off went the kazoo sending photons of light in three or five different directions with the hope something would "stick."

In general I think the approach "works."  I've only worked a handful of RAW images after the fact.  What I would like to do differently next time is to use 0.3EV bracketing in place of the rather coarse 0.5EV steps.  And I would like to see if I can make the highlights "sparkle" a bit better, while retaining a sense of "richness" of tone that comes with B&W contrast set to -3.

Kapuzinergruft - Wien 2025 

Tuesday, April 29, 2025

Software Intervention ~ Takumar 28mm f/3.5 SMC vs Sigma 24mm f/3.5 DG DN

One of the basic assumptions about lenses for photography that I have accepted unchallenged is that new lenses would be "obviously better" than old lenses.  My thinking was that modern optical design tools improve optical products in meaningful/useful ways leading to technically "better" photographs.

Images loaded into image processing software undergo many adjustments _before_ a starting image is displayed.  Some of these adjustments make optical defect "corrections."  Which made me wonder about the aforementioned optical design tools.

Turning software automation off often reveals an interesting, unexpected truth.  Modern lenses may _require_ software intervention to look good.  In many ways old manual focus lenses look better.  Old lenses often exhibit less geometric distortion, less chromatic aberration, and display certain level of "sharpness", even at wide apertures, the modern lenses appear to need help with.  

This little "discovery" lit up my brain cells and got me to thinking.  What if I applied lens corrections to manual focus lenses?  Specifically, what if I corrected for spherical aberration and geometric distortion?  Not that old lenses need much geometric distortion correction, that is.  What effect might software intervention have on old lenses?

Post-Pandemic I found myself once again exploring manual focus optics.  Previously I'd made a decision to move to all modern AF but, it appears, an Old Itch still needed to be scratched.  I now have several beautiful Takumar, ever more Nikkors (including one particularly early SLR F-mount lens), Pentax-M, and third party Kiron.

Recently, I found myself in a favorite location and took two similar focal length lenses off to a car show. One lens was a new Sigma 24mm f/3.5 DG DN.  I really like this lens.  It's light, sharp, and the AF is blazing fast.  It has never let me down and is a jewel of an optic.

The other lens was an old c.1970's Asahi Takumar 28mm f/3.5 SMC (version 2).  It is a multi-coated 49mm filter thread later version of that focal length.  It, too, is very light, compact, very smooth focusing, and relatively quick and easy to use.  In fact, it, too, is a little jewel of a lens.

Setup ~ 

  • Sony A7RII set on a tripod 
  • 2 second self timer
  • ISO100 
  • Images shot at f/11

Image processing ~

Deployed four RawTherapee tools, starting from a "neutral" profile (thereby avoiding  automated software intervention) -

  • Demosaic 
  • Color management (Sony Camera "Standard" .dcp)
  • Automated Chromatic Aberration correction ~ RAW -> chromatic aberration
  • Capture Sharpen image sharpening ~ RAW -> Capture Sharpen (note: not USM)

Here is an example of what I see -

Takumar 28mm f/3.5 SMC vs Sigma 24mm f/3.5 DG DN i-Contemporary 

Comments ~

I once again confirm for myself that software intervention can be quite useful, regardless of the vintage of a lens.  In fact, old lenses tend to require less software intervention.

If I didn't already know which lens was which, there's no way I would be able to tell the difference between the old Takumar and the new Sigma.  Can you see any meaningful difference?  Maybe my eyes are getting old, but I can't.

While this is just one very small, minor example of what software intervention can do for images taken with old manual focus lens compared with modern AF .lcp enhanced optics, I see similar things with nearly all my old lenses. 

Thursday, April 24, 2025

Software Intervention ~ a few musings

Back when dinosaurs roamed the earth I photographed using film and printed my own black and white images.  For a short time (four years) I printed for various labs around southern California.  My colleagues and I were involved in various projects, including making limited edition runs of various things for different galleries and producing prints for exhibitions and portfolios of famous photographers.

Musée national de la Marine à Paris

I felt I had a good working knowledge of the requirements that met customer expectations.  To meet those requirements, our equipment and chemical processes were carefully controlled.  Our enlargers were carefully aligned (Omega D-series were easy compared with Beseler).  The enlarging lenses we used were the best we could find (EL-Nikkor, Schneider Componon-S). The chemicals were mixed in a consistent way and temperatures were carefully monitored.  We used densitometers to verify everything was as expected.  Lamps were left on to ensure constant temperatures in condenser enlarger heads and we waited a moment after putting a negative in carrier into the enlarger so the negative would snap into flatness (if it matters and you don't understand what I just said, ask and I'll try and explain a little further).  Global image contrast was controlled by selecting paper types and/or filters.  Local corrections were made using dodging/burning techniques.

We did all these things to make certain the field of film grain would be absolutely sharp from extreme corner to extreme corner across the entire print while working to reveal the subject/scene in all its potential glory.  Making good prints was a mixture of alchemy, art, and craft.

Digital image processing comes with a few more tools than what were available to us "back in the day."  Using these tools helps us to go beyond what was done in the Old Dinosaur Film Days. 

Musée national de la Marine à Paris

Mulling such things over in my mind, I thought it might be interesting to comment a little on the topic.  Here's a list of things we can do in digital to "improve" a basic image beyond film era global contrast and local dodging/burning.  We can now correct/control:

  • Optical distortion (pincushion, barrel)
  • Chromatic aberration
  • Optical vignetting (illumination fall-off around the edges)
  • "Sharpness"
  • "Local contrast" 

Here's a short list of the kinds of things that won't be corrected/controlled with neither film nor digital. 

  • Optical coma effects
  • Optical field curvature (field flatness)

There is (at least) one thing printing from film could do that is more than a little different in digital, and that is image enlarging.  Non-contact printed film sizes obviously require enlargement.  Digital is a different beast, though digital tools exist that enable enlargement possibilities.  I've found G'Mic's DCCI2X and CNN2X upscaling tools to be fairly convincing in taking a 42mpixel image and turning it into a 160+mpixel monster.

I've said a few things about how I feel I can make an old film-era lens look like a new digital-age one.  Using automated chromatic aberration correction and Capture Sharpen in RawTherapee takes my images a long ways toward matching the performance of my new digital AF Zeiss.  If an old lens suffers from lower contrast, a gentle Local Contrast and/or USM application finishes the job.

Musée national de la Marine à Paris

Taking the Insanity a little further, yesterday I downloaded a Leica Q2 .dng file and looked at it long and hard.  Given Leica's reputation I thought I might see some magic that's not commonly seen in other camera systems.  However, I wasn't "grokking" it, so I turned on/off the various software interventions... and... oh!... sure enough, image processing corrects/changes the outcome, even with hugely expensive Leica.

It's all rather exciting, actually.  Digital image processing software intervention can "democratize" image quality.  

Old lenses?  New lenses?  Apparent image "sharpness?"  On some level it's pretty much all the same.  Which is, I'm sure, partially the point some people try to make when saying things like "equipment doesn't matter."  Of course "equipment matters", but maybe not just in ways I usually think.

One Last Thought: There's something of a community of old lens user-commenters ("influencers?" - perish the thought) on various sites/platforms spouting/touting/sprouting the benefits of using old lenses.  They tend to say things like "old lenses have so much "character"..." and "modern lenses are so "clinically" sharp..." If what they want is "character" maybe they should try turning off software intervention on modern lenses and see what happens.  It might boggle/confuse/re-inform their world view.  Not that there's anything wrong with using old manual focus lenses, right?


Sunday, April 20, 2025

Software Intervention ~ chromatic aberration, capture sharpen, local contrast, and USM corrections on a Super Cheap Kiron 28mm f/2

In the prior post I looked at chromatic aberration and capture sharpen corrections on a beautiful old Nikon Nikkor-S 50mm f/1.4 c.1972 lens.  I then took a small step to see what controlling local contrast and adding a very light USM might have and found the old Nikkor could match (under many circumstances) the performance of a Sony 55mm f/1.8 FE ZA that was managed by the common and now customary lens correction profile (.lcp) file.

For this post I want to consider similar software interventions on an incredibly inexpensive Kiron 28mm f/2 as well as a cheap, widely available Pentax-M 28mm f/2.8.  Nobody seems to like these lenses and prices on the open market tend to reflect this thought. 

Setup ~ 

  • Sony A7 set on a tripod 
  • +1EV (because of the strong whites and knowing whites saturate at EV+3.5) 
  • 2 second self timer
  • ISO100 focusing on the central flower
  • Images made at f/2.8 and f/5.6
  • Processed in RawTherapee 
Voila! encore a mundane scene of my Rescue Orchid - 
 
Kiron 28mm f/2 Scene Setup
 
 Taking five processing steps and sharing the results in the following image -
  • Demosaic and only color management as the starting point
  • Add RAW -> chromatic aberration correction to the starting point
  • Add Capture Sharpen to chromatic aberration, demosaic, and color managed image
  • Add Rawtherapee -> Detail -> Local Contrast very light amplitude = 0.05
  • Add Rawtherapee -> Detail -> Sharpening USM

Kiron 28mm f/2 vs Pentax-M 28mm f/2.8 ~ software intervention

Comments ~

Well, well, well... would you have a look at that, will 'ya?  Incredible, isn't it?  Or, if you've become somewhat jaded to the whole exercise, like me: Huh.

Identifying the tools .lcp files use to correct modern AF lenses and then applying that knowledge to isolating and using similar tools on old manual focus lenses has shown me several things.

First, in surprisingly many ways, modern lenses require software intervention to look as good as they do.  Second, designers of earlier lenses, using by today's standards rather rudimentary calculations, were able to achieve decent performance in terms of field flatness, field distortions, and chromatic aberration.

While there may be little to nothing software can do to correct for field flatness, coma at wide apertures in high speed lenses, or resolution fall-off toward the edges of a field (such is commonly seen in early wide angle lenses at the extreme corners), software intervention seems to work wonders on old lenses in just about ever other way.

From my perspective there is nothing to fear from using old lenses.  To prove this point I may post a few images I've recently made to see if people can tell which lens made which image.  I know, I've played this game before, so we'll see.

If a person can't make a decent image, it's likely not the fault of the lens, regardless of the age of the optic.

Saturday, April 19, 2025

Chromatic Aberration ~ software intervention Nikon Nikkor-S 50mm f/1.4 vs Sony 55mm f/1.8 FE ZA

Now that I was on a roll looking at chromatic aberration and sharpness software tools I hauled out an old Nikon Nikkor 50mm f/1.4 c.1972 and a currently manufactured Sony 55mm f/1.8 FE ZA. 

What follows is actually the second pass that I made at this specific comparison.  I tried photographing the Rescue Orchid against strong backlight and found the Nikkor-S flares badly.  So I flipped the scene around and shot with the light coming from behind me.  Chromatic aberration was still present, so I was able to process the way I've learned works well.

Then I took two additional software tools and tried to match the output of the Nikkor-S to that of the Sony 55mm.  I wanted to confirm what I already suspected, which is to say, with a little help, old lenses image might be made to look every bit as good as new.

Setup ~ 

  • Sony A6300 set on a tripod 
  • +2EV (because of the strong whites and knowing whites saturate at EV+3.5) 
  • 2 second self timer
  • ISO100 focusing on the stick 
  • Images made at f/5.6 and f/11
  • Processed in RawTherapee 
Voila! encore a mundane scene of my Rescue Orchid - 
 
Scene for Nikkor S 50mm, Sony 55mm CA comparison
 
Three processing steps and sharing the results in the following image -
  • Demosaic and only color management as the starting point
  • Add RAW -> chromatic aberration correction to the starting point
  • Add Capture Sharpen to chromatic aberration, demosaic, and color managed image

Sony 55mm f/1.8 FE ZA, Nikon Nikkor S 50mm f/1.4 CA Comparison

Using  

  • Rawtherapee -> Detail -> Local Contrast 
  • Rawtherapee -> Detail -> Sharpening 
 I took a quick look at matching the Nikkor-S to the Sony FE.

Software Intervention comparison

 

Comments ~

As in prior comparisons I see that the automated chromatic aberration correction does a fine job here.  There's not much CA in the Sony FE, so this lens is easy on the CA tool.  There is a bit more CA in the Nikkor, but this, too, cleans up quickly and nicely.

The Nikkor-S has less local contrast and is a touch softer than the Sony FE after CA correction and Capture Sharpen.  Adding two tools, then gently nudging the local contrast and USM sharpness I was able to show myself that at f/5.6 and f/11 the Nikkor-S and Sony FE have little useful/important/visible difference between them.

 

Friday, April 18, 2025

Chromatic Aberration ~ software intervention Nikon Nikkor-P 10.5cm f/2.5 c.1959/1960

Once I sorted out how to apply chromatic aberration software corrections to old manual focus lenses I set about to have a look at a few of my oldest lenses, beginning with a well used, mostly clean glass Nikon Nikkor-P 10.5cm f/2.5 9 aperture blade "tick-mark" transition c.1959/1960 lens.

To review, here's how I enabled automated chromatic aberration correction in RawTherapee.

 Rawtherapee -> RAW -> Chromatic Aberration Correction -> select Auto-correction

Pretty simple, right?

Setup ~ 

  • Sony A6300 set on a tripod 
  • +1EV (because of the strong white back-light) 
  • 2 second self timer
  • ISO100 focusing on the stick 
  • Images made at f/2.5, f/4, f/5.6, and f/8
  • Processed in RawTherapee 
Voila! encore the mundane scene of my Rescue Orchid - 
 
Scene for Nikkor P 10.5cm f/2.5 CA comparison
 
I took three processing steps and share the results in the following image.
  • Demosaic and color management only as the starting point
  • Add RAW -> chromatic aberration correction to the starting point
  • Add Capture Sharpen to chromatic aberration, demosaic, and color managed image

Nikon Nikkor P 10.5cm CA comparison

Comments ~ 

There's not much to say.  It's obvious there is little CA in this lens.  It renders beautifully at all apertures.  Using chromatic aberration and "sharpness" software intervention on this optic feels like it brings this ancient lens right into line with modern products quite nicely.


Thursday, April 17, 2025

Chromatic Aberration ~ software intervention Nikkor, Pentax-M, Takumar

Looking at software intervention for correcting chromatic aberration in a new Sigma 24mm f/3.5 i-Contemporary lens and learning just how important (reliant?) lens correction profiles can be to image processing, I turned my attention to three old manual focus lenses to see what might be done for them.  The challenge is, of course, that there are no lens correction profiles (.lcp) files for old lenses.

Fortunately, RawTherapee provides a surprisingly complete set of tools to work with.  Opening this software I see a tool that might be useful for correcting chromatic aberration.

Rawtherapee -> Transform -> Chromatic Aberration Correction 

There are two sliders to work with and I can look at contrasty edges of a subject and use the tool to remove CA color tints.  I can then save the settings as a recipe and recall it later as needed.

Looking around the software a bit further I stumbled upon an automated method.

 Rawtherapee -> RAW -> Chromatic Aberration Correction -> select Auto-correction

This tool automatically detects and removes CA shortly after demosaicing an image.  This tool appears to operate earlier in image processing than the Transform CA tool.  All I need to do is save a single recipe with the RAW CA correction enabled and I no longer have to store individual lens recipes.  This is the tool I used in the following comparison.

Setup ~ 

  • Sony A6300 set on a tripod 
  • +1EV (because of the strong white back-light) 
  • 2 second self timer
  • ISO100 focusing on the stick 
  • Processed in RawTherapee 

I compared three old manual focus lenses ~

  • Nikon Nikkor 24mm f/2.8 Ai
  • Pentax-M 28mm f/2.8 
  • Takumar 28mm f/3.5 SMC (second version)
Voila! a mundane scene of my Rescue Orchid - 
 
Scene of CA investigations
 
In RawTherapee and for each of the three lenses I took three processing steps and share the results in the following image.
  • Demosaic and color management only as the starting point
  • Add RAW -> chromatic aberration correction to the starting point
  • Add Capture Sharpen to chromatic aberration, demosaic, and color managed image
Nikon Nikkor 24mm f/2.8 Ai CA processing
Pentax-M 28mm f/2.8 SMC CA processing
Takumar 28mm f/3.5 CA processing
 
Comments ~
 
RawTherapee's automated chromatic aberration correction tool works the treat.  It cleans up the CA tints and my impression is that an image becomes sharper in just this one simple step.  Then, with the addition of Capture Sharpen, images from old manual focus lenses can match their modern optical counterparts.
 
The old lenses I used here showed less CA than the Sigma 24mm I compared them against.  These lenses must be lighter on the tool to achieve similar results. Modern versus old?  At this level it doesn't seem to make much difference.  
 
My Nikon Nikkor 24mm f/2.8 Ai produces images that have felt "fat" to me.  I've often wondered about that.  Now I understand.  The "fatness" comes from un-corrected CA.  When the CA is cleaned up I doubt anyone could tell the difference between the old Nikkor and the new Sigma.  Images are "clinically" sharp after a little processing.
 
All hail software intervention.

Wednesday, April 16, 2025

Chromatic Aberrations ~ software intervention and a Sigma 24mm f/3.5 i-Contemporary

It was rather surprising to me that my Sigma 24mm f/3.5 i-Contemporary lens shows as much chromatic aberration as it does.
 
If I believed the Marketing Wizards I would've thought computer optimized optical design (such as what I was led to believe is used in current auto-focus lens design) would've been a vast improvement over earlier hand calculations (such as what was generally used to guide manual focus lens design).  Clearly this is not always the case.  There is something more going on.
 
Image processing software comes with lens correction profiles.  They correct for geometric distortion, vignetting, and chromatic aberration.  So I thought I'd have a look at how .lcp files modify the character of a currently manufactured lens.
 
I'm not sure if users can select individual corrections in RentWare products.  I imagine that people don't know nor care about the underlying automation.  In the case of RawTherapee, I _can_ select the corrections I want and I use this ability for this comparison.
 
Setup ~
  • Sony A6300 set on a tripod
  • +1EV (because of the strong white back-light)
  • 2 second self timer, ISO100
  • focusing on the stick
  • Processed in RawTherapee 
Voila! a mundane scene of my Rescue Orchid - 
 
Scene of CA investigations
 
In RawTherapee I took three processing steps and share the results in the following image.
  • Demosaic and color management only as the starting point
  • Add chromatic aberration correction to the starting point
  • Add Capture Sharpen to chromatic aberration, demosaic, and color managed image
Sigma 24mm f/3.5 i-Contemporary CA processing 
 
Comments ~
 
The effects of software intervention on image processing should be rather obvious.  My Sigma 24mm f/3.5 i-Contemporary lens goes from showing a lot of chromatic aberration to becoming a sharper looking image at the first step of software chromatic aberration control. Then adding Capture Sharpen and the image takes another leap in perceived "sharpness."  After applying just these two software tools the lens behaves very well.
 
Which raises another question: Are there any tools a person can use when shooting with old lenses?  Can software correct chromatic aberrations in old lenses that do not have lens correction profiles?  I will try to answer this in the next blog post.

Tuesday, April 15, 2025

Chromatic Aberrations ~ new vs old lenses

I'm not sure how it came to me, but I had a question of how chromatic aberrations might effect the appearance of "sharpness" in an image and took five lenses of relatively different vintages to have a look.

Software automation can correct for various optical "defects", including field distortion, chromatic aberrations (CA), and "sharpness."  As a first step for my comparison I would need to turn all of that off to note what just the lens was doing.

You see, I had the sneaking suspicion that modern lenses were being tweaked into fabulous goodness by lens correction profile, or .lcp, files that are often hidden from a user during RAW image processing, but I wasn't sure.  I'd heard over the years many marketing claims as to new lens design technologies improving all manner of traditional optical defects, so maybe the .lcp files weren't doing as much as I thought?

The lenses on hand included:

  • Nikon Nikkor 24mm f/2.8 Ai
  • Pentax-M 28mm f/2.8
  • Sigma 19mm f/2.8 EX DN E
  • Sigma 24mm f/3.5 i-Contemporary
  • Takumar 28mm f/3.5 SMC (second version)

Using a Sony A6300 set on a tripod, +1EV (because of the strong white back-light), 2 second self timer, ISO100, focusing on the stick, then processed in RawTherapee using only the demosaic and Camera Standard tone-curve enabled color management steps (to keep software processing to an absolute minimum).  

Voila! a mundane scene of my Rescue Orchid - 

Scene of CA investigations 

There were a few surprises awaiting me.  Looking for chromatic aberration, here's what I found  -

Comparing CA without processing intervention

Comments -

The Sigma 24mm f/3.5 shows the strongest chromatic aberrations of the five lenses I looked at whereas the old Pentax-M and older Takumar 28mm lenses show the best CA corrections.  Even the Nikkor 25mm appears to show less CA than the Sigma 24mm and is perhaps better at CA correction than the Sigma 19mm f/2.8 APS-C.

Looking at how CA effects the sense of "sharpness" I see that, yes, indeed, images look less "sharp" when CA is stronger.  Makes me wonder how much modern lenses rely on software intervention to make them look as good as they do?


Sunday, January 05, 2025

Countering the rising costs of photography ~ On Being A BottomFeeder

Thom Hogan has written an excellent article that observes and comments on the rising costs of photography and the sources of those costs.

Being the contrarian penny pincher that I am, I thought I'd give a few examples of how I no longer "play that game."  In fact, I've not "played that game" for decades.

When I had a job and could afford such things I would buy new pieces of camera equipment from time to time. The last new camera I bought was a Sony A6000, and that was well over ten years ago.  Though, thinking about it a moment, maybe the last new camera I bought was a Sony A5000.  The memory fades.

Most of my efforts however, even when I worked, were buying/using/selling used gear.  Hundreds and hundreds (more likely thousands) of lenses and cameras have passed through my hands over the years.  The habit carries forward into the present.

On the image processing side of things I leveraged my knowledge of and contacts with the Open Source community, and experiences of deploying large scale Linux systems.

So, my costs have been traditionally low.  I see no reason why someone truly interested in photography either as a hobby, artist, or working professional can't do something similar.

Musee d'Orsay, Paris ~ 2024

Sony A7RII, Sony FE 35mm f/2.8 ZA
RawTherapee, Digital Zone System
Pt/Pd tinted

Here are a few things I do.

Buy Used -

It seems like an obvious place to start. 

If I worried about reliability the thing I note is that most of my used cameras these days are very "low mileage."  One Sony A7 I bought had around 800 clicks on the shutter, looked well cared for, and set me back 450Euro five years ago.  Another had less than 2,000 clicks for a slightly lower price, again, five years ago.

On the other end of the spectrum, I recently picked up a Sony A7RII with 72,000 clicks for a nice low low price.  This, even though the camera remains in excellent condition and the shutter is rated for 500,000 clicks.

Similarly, used lenses can be attractively priced.  For less than the price of a new Sony A7III body (even on sale) I've been able to build an A7 kit with three fixed focal length lenses.  Two lenses are usually expensive Zeiss labeled and one is like new latest generation Sigma.  All are auto-focus, modern optics.

Thinking again about reliability, of all the used gear that's passed through my hands, there's not one single "bad deal" that I can recall. I take that back.  I bought a Fuji 240mm A f/9 large format lens many years ago that arrived with difficult to see sand-impacted front element.  It was returned for a full refund and the seller apologized.  He remembered he'd recently taken the lens to Death Valley where it had been windy.

Image Processing -

I tend not to spend too much on computers and stick to using a laptop.  Any decent quality device will do.  HP, Dell, and, hmmm... that's about it, actually.  For security reasons I assiduously avoid anything designed/manufactured/marketed by the Chinese.

Once an inexpensive computer is at hand, I wipe the disk and install a decent distribution of Linux.  That OS remains for me the most secure way of engaging the world.

On top of Linux I load the image processing applications I like.  These include RawTherapee, the Gimp, Luminance HDR, and Hugin.

I use RawTherapee for performing the "heavy lift" image processing.  When I need to "tweak" something or want work graphically I transition to the Gimp.  While I've not done a lot of HDR recently, I still low Luminance HDR, just in case.  When the bug hits and want to make my computer cry I use Hugin to stitch very large high resolution images.

Over the years I've paid close attention to differences between commercial and Open Source software capabilities.  What I've found is that Open Source software can be more complex and require more steps to accomplish common tasks.  Coming from commercial software where many potentially important details are hidden from users, Open Source software can be a little overwhelming at first.  

Part of the challenge is that there are so many options and tools and standards that is seems as if nothing is being left out.  However, and this is important to me, once I understood the tools and specifications implemented by those tools, I've come to realize there is nothing more flexible, more comprehensive, nor more accurate (in particular color management) than something like, say, RawTherapee for image processing. 

In fact, if I felt I couldn't live without Adobe "color science" or Fuji "film simulations" or Hasselblad "Natural Colors", all I'd have to do is load the .dcp and .icc files into RawTherapee and select the styles and looks I want during processing.

To back everything up, I buy new USB drives.  This is one thing I will not buy used.  New 5tb spin drives are shockingly inexpensive.  Solid State drives are becoming more affordable.  Everything, RAW files, processed images, documents, works in progress, everything, gets tossed onto a drive every so often.  And I'm tending to keep multiple backups, too, "just in case" something fails down stream.

That's just about it.  Very simple.  Very straight-forward.  Nothing fancy.  I don't pay rent on any software.  No Apple tax.  No Microsoft madness.  No Adobe rent until I die silliness.  I own my cameras and lenses outright and at as low a price as the market offers.  I don't get a boatload of noisy advertisements from the apps and OS I use.  My systems are secure, stable, extensible, and portable.

There you have it.  This is how I manage my photography eco-system costs while living on a fixed income.