::I agree with .  He is not saying that one can convert to a hybrid AF system if the needed hardware is not there.  In his examples, one requires the AF-assist lamp (projecting a pattern usually, so it will allow focusing even on untextured surfaces in some cases), and other requires the special phase-sensitivity pixels that are built into some sensors to support hybrid AF.  Hybrid AF systems predate digital cameras (see e.g. ELPH 370Z), so restricting the definition to the latest generation of phase + contrast hybrids is too narrowing.