This is how you can match blender's virtual camera to the characteristics of the (real) Helios 44-2. A trick that can be quite useful when you are rendering out photorealisic visual effects that are supposed to look like they were shot with your specific camera.
Gleb Alexandrov's fantastic tutorial:
https://youtu.be/kfyn6Sp-jSk
Jojo's gem of a tutorial:
https://youtu.be/xxkUNG-bpxs
Get the smoke asset pack for free: https://calzaath.gumroad.com/l/smoke (USE CODE "SMOKE")