There’s a long history of lens-less photography. Sad how quickly the bristles come up when the word “computer” is applied… does it remind me of the nonsense of 20 years ago, when the old guard against digital cameras were frothing that (commercially manufactured) film had “soul,” unlike those evil digital Nikons and their fickle lenses? Were these declarations being made on the internet, while sharing digital copies of these supposed intrinsically-soulful images? Well, of course.

This post isn’t an invitation for argument, simply an observation that a picture is a picture. It carries possible connotations about its origins, but as we should know by now the true provenance of any picture is never the brow of mighty Zeus. More on this topic to come.

A holiday sketchbook from 2005.

I made a small tool to generate this little pair of charts comparing print and aspect ratios because I simply couldn’t find one laid out this way: all centered to show the letterboxing for one axis or the other. The charts I could find invariably radiated out from the corner, which is less useful (to me) when preparing prints from existing images where the aspects don’t match.

While these charts include only the frame shapes I typically use, it’s easy to regenerate any variant you like – other sizes such as 16:9 or A4 paper are already defined in the tool: this Colab notebook. Alter as you see fit, run the notebook, and a new chart will appear in roughly a second or two.

In 1907 Ernest Rutherford realized that certain materials in rocks slowly decayed into other materials. Specifically, the newly-discovered radium degenerated into the stable isotope lead-206. He realized the decay’s speed was exponential, faster at first and slower as it progressed – in his equations he labeled the time it would take for half of the radium in a sample to decay into lead as its half-life.

From this realization he and others could compare the amounts of a specific isotope of decaying radium or (better) uranium to the stable lead in a mineral sample and use this proportion to estimate the minerals’ ages. By the end of the 1920’s they’d managed to show reliably that the age of the earth was at least 3.4 billion years old.

Works great for rocks. Also, for software & development.