Using EXIF data to pick my next lens

A neat feature of almost every modern digital camera is that every single photo you take includes detailed metadata, including all of the photo’s settings including shutter speed, aperture, sensitivity, and focal length.

The focal length, or simply the “zoomness” of your photo is of particular interest. All of the other settings are very easy to change by adjusting a dial (or using some annoying menus), but this one can only really be adjusted in a large way by changing lenses. Since most cameras come with a “kit” zoom such as the 18-55, 12-32, 20-60, or some variation of that, most people choose to purchase other lenses to get different “zoomability” out of their body.

Over the years, I’ve accumulated several of these, ranging from a 9mm ultra-wide all the way to a 150mm super-telephoto.

However, when deciding which glass to shove in a backpack before going on a trip or a walk in the park, I’ve always wondered which combination gives me the highest likelihood of getting an image I will like, without having to pack a huge bag with all kinds of heavy lenses I most likely won’t use.

To answer that, I threw together this python script to read the EXIF data from my favourites of the past several years of photos, aggregate it by focal length ranges, and display a basic histogram in my terminal.

Based on this, I can quickly see that the range with by far the most photos is 15-20mm (35mm ish on full frame). This is very interesting to me, since I’ve previously purchased and used a 25mm fixed zoom lens, but it still hasn’t eclipsed my use of the wider 15-20mm range.

Another interesting observation from this data is that I rarely use the mid-range of my telephoto zoom, with several in the 50-55mm bucket and even more right at the end of its 150mm zoom limit.

And so, I can now say with confidence which gear to take on my next vacation, with the data to back it up!