Originally posted by Wasp Yes, that extra stop makes a big difference. One can really push the envelope at f/1.4, especially on older bodies. Here is one taken by a dim streetlight, wide open at ISO 12800 on my trusty Kx. With an f/2 I would have had to haul out a tripod. A modern body like a KP would do fine with an f/2 but I don't have one (yet).
Edit: The extra brightness in the viewfinder that an extra stop gives you is very useful for framing and focusing, but I have never compered the f/1.4 and f/2.0 in that respect.
---------- Post added 2019-05-19 at 22:16 ----------
Indeed it is, my bad. I also neglected to mention the M 150/3.5. There were certainly some unique focal lengths in the lineup in the Asahi days. AFAIK Canon and Nikon never offered a 120 or a 150.
Alrighty, I'll keep looking for one then! I've got a K-5, so I could probably make due with f2 if I push the ISO up, but I like to keep it low-ish.
The KP would be a great fit for the compact M series lenses I bet!
Yeah, those less common focal lengths have some charm to them. I've been looking at the K55/1.8 for that reason, probably makes a nice portrait lens on APS-C.