Sony doesnt make DSLR cameras, there is no 'reflex mirror'. These are mirrorless cameras, or Interchangeable Lens Cameras E-Mount (ICLE) as sony calls them
You don't know what you don't know. I'd assume any significant timeline involves broadening our understanding of thermodynamics and material science. I don't think its far fetched to presume that another species is further along on the Kardashev scale.