Things I learned: 2018#18

  • Tailwinds clearfix cannot be applied to pseudo elements as it uses pseude elements itself.

  • In go a type matches an interface if the definitions line up. No matter if the interfaces have anything to do with the type or not.

  • I use (and love) AfterShotPro for editing of RAW photos. One free and OpenSource alternative is Darktable - which in contrast I find to be very cluttered and hard to use. However, clipping highlights are handled much more gracefully in Darktable compared to AfterShot.

  • Neutral density filters (ND) for cameras are rated with relative numbers of darkening. A ND2 Filter will make everything half as bright - a ND4 Filter will make everything one fourth as bright - a ND64 Filter will reduce the brightness to 1/64th. Usually the exposure of a photo is measured in stops - which is a logarithmic (log2) scale: 1 Stops is twice as much light. Therefor the number on a filter and the stops it darkens the image by diverge. This is where being a developer and learning your powers of 2 finally pays of.

  • Expanding on the last point: Photographers are not as familiar with powers of 2 so manufacturers will often simplify the names: A filter that darkens the image by 10 stops should be called ND1024 (2^10 = 1024) but is most often referred to as ND1000. Much more ridiculously 9 Stop filters are called ND400 (Should be ND512). I have not found an explanation why it is not rounded to 500.

  • A single GPG Key can be used for multiple E-Mail adresses.

  • Once a GPG Key is on a keyserver there is no way of getting it off. All you can do is revoke the key and inform the server that the key is no longer valid. This in turn requires that you still have a valid private key. If you accidentally deleted your private key then you are out of luck.

  • I can sign a GPG Key of someone else with my GPG Key to indicate that I trust this person and their Identity. this way it is possible to build what is called a ‘web of trust’ of identities and keys that are trusted by peers.

  • bc is a calculator on the command line.