03 December 2023

Different premises, different conclusions

As will be apparent to anyone reading this blog, bird photography is a Thing for me. This is an activity ordinarily pursued with a long lens; my usual setup totals about 5 pounds, or another half pound if I add a teleconverter. I'm used to toting it, but it does get heavy after a while, and I might not want to pack it if I were going on a trip that wasn't targeted at birding. So, I was interested in finding a possible alternate optic that might be usable even if not quite as good. I was intrigued to find that I could buy a used Canon 70-300 DO lens in excellent condition for less than $350 USD. This lens is notably shorter than others in its focal length range, thanks to its use of Diffractive Optics (DO) technology. It was expensive when it was introduced in 2004, and opinions about its sharpness and contrast for an expensive lens have been mixed

In 2004, digital camera technology wasn't nearly as advanced as it was today. A 6 or 8 megapixel sensor was competitive in consumer-grade DSLRs, which limited the number of pixels that could be cropped away to frame a small subject without visibly diminishing resolution. Sensors were also less capable of operating at high ISOs without becoming excessively noisy. Since bird photography often requires fast shutter speeds, high ISO usage is often necessary.

Today's sensors are much larger and can reach into higher ISO territory before becoming intolerably noisy. Digital post-processing technology provides impressive denoising capability, and AI software products like Topaz Photo AI can often extract or reconstruct image detail that's otherwise lost to the naked eye. One relies on the AI to derive and reflect detail that's actually present in the scene being photographed rather than hallucinating artifacts that aren't, but that's a larger question that I won't attempt to reconcile here. Rather than considering the output from a camera as necessarily comprising an end result in itself, it can now be provided as the input to constructive post-processing. The test of a camera and lens combination, therefore, need not be the appearance of the photos that it outputs directly, but rather whether the information contained in them (most likely, in their RAW files) is sufficient and suitable as a basis to create even better results digitally.

When I looked at a trial image taken with the DO lens (significantly cropped, as most of my bird photos are), it seemed rather noisy as it came from the camera, but exposure at ISO 3200 on a dim day could explain at least some of that.

More broadly, I wasn't seeing as much detail in the bird and its surroundings as I'd like for my collection.

Sharpening and denoising in Darktable provided some improvement in another version.

I still hoped for better, though, and thought that the Topaz software provided an impressive result.

I think the DO lens will be a useful complement to my current setup, but would probably have been disappointed if I weren't able to apply post-processing technology to the images it collects.

24 September 2023

Chromebook and Linux for Travel and Photography

I enjoy making the most of lower-end devices and appreciate economy, portability, and ruggedness. For a travel computer, I want something that I can throw into a bag without much worry about cushioning, that I wouldn’t have spent so much on that I’d feel far out of pocket if it were lost, and that I might even be able to unfold on an airplane seat. Long battery life is another desirable attribute. So, I bought a new 11” Chromebook, of the sort designed to be handled roughly by school kids, a Dell Chrome 3110 2-in-1. It has 64GB of storage and 8GB of RAM, with a Celeron N4500 processor. (Note: there’s also a 32GB/4GB version of the same model, which seems to have better availability. I didn’t want or select that one.) The keyboard has a good feel and a comfortable amount of travel. As a significant extra bonus for me, it includes native Linux support, which fits many of my preferences and application needs.

I attempted some photography and photo processing through it before traveling:

  1. Take RAW photos in rather dim weather.
  2. Extract memory card, plug into Chromebook via USB card reader.
  3. Select-all of RAW files on memory card, copy to folder on Google Drive. I was interested to see that it copies many files in parallel with individual completion indicators, maximizing use of available bandwidth. I subsequently found that it’s not necessary to do the manual select-all, and can instead just copy a folder. Nonetheless, it still takes a while to push many RAW files through the 12Mb upload speed of a cable Internet connection.
  4. Find that Google Photos doesn't support Canon CR3 RAW format.
  5. Enable the Chromebook’s Linux development environment, which I believe is included on at least most fairly recent Chromebooks, obtaining a shell in a Debian instance.
  6. In a spirit of "why not?", install Darktable as a Linux app on the Chromebook, via Flatpak to get a more current version than the older one in the Debian repository. Icons for Linux GUI apps appear alongside other Chrome apps in a folder named "Linux apps" so you can launch them alongside anything else you run in a Chromebook like the native apps or Android apps. Clever.
  7. Launch Darktable and import photos from Google Drive. This creates references only, not retaining the raw files themselves within limited Chromebook storage. From the ChromeOS environment, it’s necessary to use a menu option to grant folder access to Linux. Darktable’s sidecar files appear alongside in the Google Drive folder and can be accessed later to preserve edits made when mobile. Some patience is required as new photos are imported and thumbnails are generated.
  8. Raw-develop and edit with Darktable, as if on a more powerful computer though slower and obviously with a tiny screen; raw development takes a few seconds on a 32 MP RAW file, but works.
  9. Export generated jpg back into Google Drive.

I'm impressed that this is possible and, after a trip where I shot about 1400 photos, found that it offered a useful travel capability for archiving and for developing, editing, and posting a few shots while on the move like this Sandhill Crane:

I imported daily folders with a few hunderd RAW images into Google Drive and watched them synchronize through hotel WiFi into the cloud in under an hour, but the actual elapsed time depends critically on tha available upload data rate. (Warning about hotel WiFi, BTW: if a Chromebook is freshly started, it may have trouble launching a new Linux container instance until normal Internet access is available; a captive hotel login page may not suffice. This didn’t seem to be a concern if the Chromebook already had a live container and was just being resumed after suspension.) If the Chromebook went idle, the sync paused, but it resumed in place once the machine was awake again. It was notable how Google's integration between the Drive file system and the Linux container "just worked", and that the Darktable instance was able to find a folder there via its chooser.

A few things I’d like to improve for a next round:

  • Automate extraction of images from a camera memory card into folders organized by days, keeping accumulated images on the card but also copying each into Google Drive once and only once. It may also be useful to explore camera options for folder placement and photo numbering to better facilitate this.
  • Figure out how to keep Google Drive’s cloud sync uploading actively even when the Chromebook is otherwise idle. (There may be an obvious configuration option somewhere that does this, but I haven’t yet stumbled on it.)

17 February 2023

Perceptual adjustment

I had what I thought was an interesting experience when editing one of my photos. Look at the first view before proceeding to the second one, and get a sense of the image as you parse it. I thought it looked (strangely but convincingly) like some sort of a mountain scene with a glacier or river draining into a pool, with some very large bird overhead. 


Modest recropping with added information in the second view changed that assessment for me, putting the view into its actual context of a small scene, with seafoam streaming around moss-covered rocks. 

Did the two other Purple Sandpipers in the lower left have the same effect for you, or did you interpret the scene accurately in the first place?

09 February 2023

Overlooking the ocean

 I visited Halibut Point State Park in Rockport, MA the other day, where the quarry was partly frozen over:

There was much Nice Ice to see:

I saw this sign:

I didn't think the Atlantic was an ocean that should be overlooked, so I went to the overlook to overlook the ocean. I quickly discovered that there were more Harlequin Ducks than I think I've ever seen in one place at a time, counting at least 18 in this view:
I came home with over 100 images of them, such as this lineup of interested males:

And a closer approach:
 Followed by dispersal:
And a flyer: 
And also some Long-tailed Ducks, including one whose expression seemed quite imperious:

It was a fine day out. I'm glad I went.

13 September 2022

Update day! Whee!

Ubuntu's 22.04.1 LTS release came out fairly recently, and I had it on my to-do list to get around to updating some components of my personal digital empire once it did. I'd already been using 22.04 on my desktop for several months, to general satisfaction and particular appreciation of its having included a new enough version of Darktable to handle the CR3 raw format that one of my cameras produces.

So, to the updating. I have a DigitalOcean droplet that runs the Nextcloud snap. I like having a small bit of cloud that I can manage myself, primarily to share files among devices and sometimes with others. I use memory cards with higher storage capacity than the minimal droplet's 25GB, but it serves its purpose. sudo do-release-upgrade worked fine. One system checked off.

I also have a home server, which also hosts a Nextcloud alongside other services, for larger-capacity sharing within my LAN. Here, the Nextcloud instance hadn't auto-updated like the droplet's snap, and I (bad me!) hadn't been attentive to updating its versions while the service continued to "just work". After the OS upgrade, I found that the Nextcloud-in-place required a PHP version earlier than the 8.1 included with Ubuntu 22.04, so couldn't generate display pages. There's a third-party repository that has older PHP releases, but I wasn't quickly able to line up the right set of configuration for the old Nextcloud to make use of it, and it was Update Day anyway! After three successive updates to Nextcloud to successive versions, I got it current and able to find and use PHP 8.1. My screen sync icon winked with approval. 

Lesson: be aware of dependencies, and do upgrades when you have time to deal with surprises.  

02 January 2022