Apart from a macro lens, I think everybody with an interchangable lens camera (this used to be simply DSLRs but now of course there’s a load of mirrorless out there as well) should have an ultra-wide angle lens (UWA). They’re just so much fun! One of the things I like doing is sticking the lens right up close to geometric architecture and watch the curvature of time and space… well kind-of. But do look at those egg-shaped atoms!
The weather here really helped to put a shine on the Atomium.
Technically the only thing that matters is the focal length – 13 mm on the standard Sigma 10-20mm f/4-5.6 (that’s the “original” version, not the newer f/3.5 and there may even be a yet newer version… I don’t know, I don’t need anything but the version I have). The rest is not particularly interesting. f/9.5 to get deep DOF – although at 13mm that could probably have been 5.6 and looked the same – 1/200 s and ISO 200… oh well.