Windows 11

My friends and colleagues often complain about Windows 11. Personally, however, I much prefer it to Windows 10. In particular, here are some standout features:

Windows Explorer now has tabs! Coming from macOS and Linux, I so missed explorer tabs that I added them to Windows 10 with a plugin. I still feel handicapped whenever I have to interact with an older Windows box that doesn't have them. But Windows 11 does. Next, please fix the inevitable hangs in Explorer, please.

Windows 11 includes a very useful clipboard manager! Just hit ❖-V instead of Ctrl-V, and select any of your previously copied snippets. I use this all the time, to copy items from multiple places into a common list. Or to share that link I copied half an hour ago.

The Windows 11 screenshot tool is hands-down the best screenshot tool of all the operating systems I know. Why? Because it captures the full screen content at the time of capture, including the mouse pointer, hover states, tooltips, and everything else. And it copies the capture immediately to the clipboard, ready to paste into documentation or notes. I hit ❖-⇧-S many times every day. Another useful feature is text recognition that is now part of the screenshot viewer and image viewer.

At work, I spend many hours every day in Microsoft Teams. Teams is not a high point in Microsoft's portfolio. But at least I can mute and unmute my microphone from anywhere in the OS with ❖-Alt-K. This is highly useful whenever I want to present something, without having to manually switch to Teams and back just to unmute myself. Oh, and after a year of waiting, the "new" Teams finally re-learned to spell-check more than one language at a time this year. About time.

Sometimes I have to annotate PDFs, especially for signing forms. Windows now includes a very competent little PDF annotator in Edge, of all places. It's not as good as macOS's Preview.app, or Okular. But hey, at least it's there.

A few weeks ago, my Surface tablet somehow broke its Windows installation and got stuck in a boot loop. System restore didn't work. Safe mode didn't work. Finally it booted me to a defeated screen saying "it seems you're f*cked". But right after that, the very new Quick Machine Recovery kicked in, re-downloaded a new copy of Windows, and recovered the machine and all my data. It took half an hour, but it worked perfectly.

I'll stop here. There are a few more notable features, but most of them are more widely known. For example, there's now a handy search feature in the Task Manager. The On-Screen Touch Keyboard is now almost as good as a mobile keyboard. The new Terminal app doesn't stink any more. the RDP client is faster and better-looking. And of course WSL keeps improving.

Next up, can I please have proper color management in the Windows shell, so app icons don't look all clownish on my wide-gamut monitor? It's 2025, and most new screens now come with decent DP3 support, so it's about time.

Phone Reliability

One of our Pixel 6a phones recently had its battery bricked by a mandatory software update. Conveniently, Google only "found out" about this issue a few months after the warranty period ended for anyone who bought the phone when it was new. Lucky for us, we had bought ours later, when its predecessor broke on vacation and couldn't be repaired. So ours was still covered by its warranty, and we got a full refund.

I noticed that issues such as this have caused all our phone replacements in the last years:

• This Pixel 6a got a mandatory update that bricked its battery, and can't be repaired before we go on vacation. So we now have to buy a new phone.
• A Pixel 5a's screen broke on vacation and local repair shops refused to repair foreign devices. So we had to buy a new phone.
• A Pixel 4a suddenly refused to charge, and I didn't want to wait two weeks to get it repaired. So I bought a new phone.

However, before we used Pixel phones, we had Fairphones, which had quite a different record:

• A screen broke when I dropped it face-first on a radiator. I got a replacement screen fast-shipped within 24h, one day before we left on a trip. The replacement screen with priority shipping cost €98.
• A battery became very weak, and we got a replacement part for €27.
• A charging port became unreliable and we got a replacement part under warranty.
• We replaced a broken headphone socket. The replacement part cost €36.

Whenever we had to replace a phone, it was because the old one could not be repaired in time. With the Fairphone, we could repair the phone easily, and thus didn't have to replace it. Needless to say, the next replacement phone will be a Fairphone.

The Perfect 23mm Lens

What's in a perfect lens? Is it sharpness? Contrast? Microcontrast? Bokeh? Whatever does that even mean?

Today is new lens day. To test my purchase, and get it out of my system, today, I will measure my new lens. It's the Fujifilm XF 23mm f/1.4 R LM WR, a preposterously complex lens for a ridiculously high-resolution camera. Will it prevail against my older Fujifilm XF 23mm f/1.4 R? How will it fare against my travel zoom, the Fujifilm XF 16-80mm f/4 R OIS WR?

First up, resolution: I printed a test chart on A3 paper. First I tried printing the PDF directly with Preview.app, but noticed that the chart itself started blurring lines at 1250 L/PH¹, which implies that Preview.app prints at 1250/8.7in≈150DPI². Not satisfied, I exported the test chart to a high-DPI tiff, and printed with Canon's print application, which appropriately resolved the finest lines on the test chart.

I took pictures of the marked 3:2 area on the chart. Since all my lenses are easily sharp enough to resolve the maximum 20 L/PH on the chart, I aligned the chart to the center quadrant of a 3x3 grid on my camera display, and cropped appropriately in post.

Each of these crops is at 1:1 resolution of the original capture, at the center of the frame, with no sharpening, straight from the raw file. Exposure was adjusted to a consistent 95% L in HSL. The red line indicates the level of resolution where the lines are just resolvable³. The resolution scale is in 300x L/PH. For instance, a resolution of 14 corresponds to 4200 L/PH, which is slightly short of the 5150 pixels in the 40 MP image. Since the color filter demosaicing is not entirely lossless, this is an excellent result.

On average, the new lens resolves a good 10% more lines than the old 23 prime, and perhaps 20% more than the zoom. In the real world, these numbers mean nothing. All three of these lenses are easily sharp enough for everything I might throw at them.

Next to the resolution is the contrast level in ΔL⁴ (HSL), measured at the right side of this pack of lines, which is a good proxy for contrast of high frequency detail, or microcontrast. A lower black level means more microcontrast. Indeed, this is where the new lens shows a clear improvement over the other two lenses, with visibly more contrast in fine details.

Also notable is a visible magenta color cast on the old 23mm prime wide open, and a minor blue color cast on the new 23mm. In normal images, color fringe suppression will mostly get rid of these, so these are not usually worrisome.

And then I repeated the procedure in the image corners. I took the same pictures, but this time the resolution chart covered the top-right quadrant of my 3x3 grid:

As expected, resolution and contrast fall off towards the image corners. For the new lens, the falloff is about 20% resolution, and 40% microcontrast at open apertures, lowering it roughly to the level of the old lens' center. For the old 23mm prime, it's about 40% resolution, and 40% contrast at open apertures, which is visibly soft. The effect diminishes rapidly for smaller apertures, however, and is mostly gone at f/4. Consequently, the 16-80 f/4 merely loses a small bit of contrast.

In summary of these objective measurements, the new lens is ridiculously good. In the real world, I would expect to see a minor difference in microcontrast, mostly visible in the image corners. But stop down, and all three lenses will perform very similarly.

As a sanity check, here's the central resolution target, shot a bit closer, to get a feeling for how the above measurements look like on larger structures:

As you can see, the differences in resolution are not a big deal in the real world, and even the contrast levels for larger subjects are not as different as the measurements might suggest. The color fringing wide open is still visible, however.

Next, let's look at the lenses' bokeh. For an objective measure, I took a picture of various film boxes along a measuring stick. Focus was at 50cm distance, with the close box at 25cm, and the far one at 75cm. This should give a good indication of the out-of-focus rendering on both sides of the focus plane.

You can see a slightly harsher bokeh and very minor color fringes in the old lens at f/1.4. But from these images, I don't see a compelling reason to choose one over the other. Curiously, at f/4, the 16-80 seems to show slightly less blur than the two primes.

For an assessment in more realistic conditions, I took a few photos of flowers and point lights. The flowers give a good indication of the focus transition from in-focus to out-of-focus, while the point lights show how specular highlights are rendered.

The transition pictures once more show a tendency for colored seams on the old prime, which is absent on the new one. This makes the new lens' bokeh seem a little smoother. Apart from that, the differences are very minor. As expected, there is no significant difference in detail between these shots. The point lights essentially confirm this, with a bit more color fringing on the old lens.

In conclusion, I found the new Fujifilm XF 23mm R LM WR slightly sharper than the old Fujifilm XF 23mm R, with noticeably less color fringing, and slightly better microcontrast. Once stopped down to f/4, these differences become insignificant. At that point, both prime lenses retain a very minor resolution advantage over the Fujifilm XF 16-80 R OIS WR.

Thus my curiosity in the technical quality of these lenses is satisfied, I verified that my lens is functioning properly, and I can now go out and shoot pictures.

The Leica Experience

In the world of photography, there is one brand that stands apart from the rest: Leica. It exudes an air of quality, refinement, and heritage. These cameras signal wealth and sophistication, and serve equally as cameras and as fashion pieces. Many of the greatest photographers in history shot their work on Leica. They are very expensive, too.

That cachet is strongest with their rangefinder series of cameras, which use an anachronistic manual focusing method that relies on optomechanical clockworks instead of digital trickery. Where you frame your shots through a plain window with overlayed framelines, but no digital display or distracting iconography of modern cameras. A reduction to the necessary, pure distilled photography, according to the myth.

It was thus with much anticipation that I took delivery of a Leica M240 with a Leica 35mm ƒ∕2 “Summicron” lens, loaned graciously by a friend from my local camera club. I have learned enough times to optimize for joy, not utility, so this could be a costly prospect if the experience should appeal to me.

The camera is indeed a beautiful object, exquisitely machined from solid metals. In an unexpected inversion of modern camera design, it sports a chunky body, but a small lens. A pleasant thing to hold, if a bit more heavy than I had expected. Operation of the camera is indeed pure simplicity. There's a shutter speed dial with an automatic setting, an aperture ring on the lens, and a focus tab. The latter two parameters offer no automation, contrary to modern cameras.

My Leica-using friends in the camera club predicted that I'd get used to the manual focusing quickly. And indeed I did. But precise focusing with a rangefinder is somewhat slow and only possible in the frame center. So where speed is required, I instead relied on good old zone focusing: pre-setting the expected distance on the lens, and stopping down a bit to get a deep zone of focus. Thus prepared to take a shot, there remains nothing but pressing the shutter button. This perfect simplicity of just being there, and worrying about nothing but the scene and the composition, feels unexpectedly freeing. On the flip side of course, framing with a window finder is imprecise, and getting accurate focus at large apertures is not easy or fast.

Another surprise were the rangefinder lenses. These are very much unlike modern designs, and focus on compactness and rendering over versatility. They are not sharp wide open, exhibit strong field curvature, and need to be stopped down to get sharp off-center. Annoyingly, the combination of field curvature and the centered rangefinder patch makes anything but center compositions impossible wide open. Still, this is actually a fair tradeoff for smaller lenses, and one I wish more modern lenses would offer, especially as it also tends to make for a smoother focus transition and bokeh.

Overall, I enjoyed the rangefinder style of shooting. However, the Leica M240 also annoy me a bit by taking too long to switch on. More than once, I raised it to my face, and it simply wasn't ready to shoot yet. It takes a good second to take the next shot, too. Even for a ten year old camera, that is annoyingly slow. I also very much missed a functional, movable back screen, to shoot from low or high angles without contorting myself into camera-yoga, and modern amenities such as USB charging and easy access to the SD card. I'm sure, however, that more modern models are faster at least, even if the back screen does remain fixed and there remains no sensor stabilization.

After two weeks with the camera, I had to return the Leica M240. This is a piece of camera gear I have long wanted to try. I felt the immediacy of the window finder, the simplicity of the rangefinder focusing, the heritage and cachet of the brand. These things were indeed beautiful. But it is still with some relief that I can conclude that this camera is ultimately not for me. I can respect anyone for whom this experience strengthens the connection with the process and images. But for me, I realized that I prefer a camera that goes out of my way, and the Leica is not that.

Python Inception

At most companies I have worked for, there was some internal Python code base that relied on an old version of Python. But especially for data science, I'd often want to execute that code from an up-to-date Jupyter Notebook, to do some analysis on results.

When this happened last time, I decided to do something about it. Here's a Jupyter cell magic that executes the cell's code in a different Python, pipes out all of STDOUT and STDERR, and imports any newly created variables into the host Python. Use it like this:

%%py_magic /old/version/of/python
import this
truth = 42

When this cell executes, you will see the Zen of Python in your output, just as if you had import this in the host Python, and the variable truth will now be 42 in the host Python.

To get this magic, execute the following code in a preceding cell:

import subprocess
import sys
import pickle
import textwrap
from IPython.core.magic import needs_local_scope, register_cell_magic
 
@register_cell_magic
@needs_local_scope
def py_magic(line, cell, local_ns=None):
    proc = subprocess.Popen([line or 'python'],
                            stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
                            encoding='UTF8')
    # send a preamble to the client python, and remember all pre-existing local variable names:
    proc.stdin.write(textwrap.dedent("""
        import pickle as _pickle
        import types as _types
        _names_before = [k for k, v in locals().items()] + ['_f', '_names_before']
        try:
    """))
    # send the cell's contents, indented to run in the try:
    for line in cell.splitlines():
        proc.stdin.write("    " + line + "\n")  # indent!
    # send a postamble that pickles all new variables or thrown exceptions:
    proc.stdin.write(textwrap.dedent("""
        # save results to result.pickle
        except Exception as exc:
            with open('result.pickle', 'wb') as _f:
                _pickle.dump({'type':'error', 'value': exc}, _f)
        else:
            with open('result.pickle', 'wb') as _f:
                _values = {k:v for k, v in locals().items()
                               if not isinstance(v, _types.ModuleType) 
                                  and not k in _names_before}
                _safe_values = {}  # skip any unpickleable variables
                for k, v in _values.items():
                    try:
                        _pickle.dumps(v)
                    except Exception as _exc:
                        print(f'skipping dumping {k} because {_exc}')
                    else:
                        _safe_values[k] = v
                _pickle.dump({'type':'result', 'value': _safe_values}, _f)
        finally:
            quit()
    """))
    # print any captured stdout or stderr:
    stdout, stderr = proc.communicate()
    if stdout:
        print(stdout, file=sys.stdout)
    if stderr:
        print(stderr, file=sys.stderr)

    # load new local variables or throw error:
    try:
        with open('result.pickle', 'rb') as f:
            result = pickle.load(f)
        if result['type'] == 'error':
            raise result['value']
        elif result['type'] == 'result':
            for key, value in result['value'].items():
                try:
                    local_ns[key] = value
                except Exception as exc:
                    print(f"skipping loading {key} because {exc}")
    finally:
        pathlib.Path('result.pickle').unlink()  # remove temporary file
  
del py_magic  # otherwise the function overwrites the magic

I love how this sort of trickery is relatively easy in Python. Also, this is the first time I've used a try with except, else, and finally.