Filmic pro is available for Android too but not my phone. (Vernee Thor). Access to flat colour profiles via Filmic sounds impressive. There are Android phones coming through now that use more than one lens to create a shallow depth of field. The next few years will see great changes (as they always do, I suppose)
One thing to be aware of. Many of the Takumars and Super Takumars around that focal length (50, 55 etc) are radioactive due to the thorium put in the glass nearest to the camera. It's not really a problem. Just don't eat it or store it down your boxers.
Excellent lenses. I have 3. They don't get the use they ought as my preference in my own collection are the Helios, the Contax Yashica and CZJ. On bang for buck, the Olympus is still the star, available at pocket money prices.
How about taking the glass out?
I watched old episodes of The Avengers recently (no not those, the ones with Steed and Emma Peel). In scenes where there was a large glass pane in a door, they removed the pane. Whilst that worked for 1960's TVs, it was entirely obvious that there was nothing there on my rather more modern flat screen.
Lenswise, in the Happy Shopper end of the budget, you also have the Helios 44 58mm f/2.0 with counterparts Mir-1B 35mm f/2.8, Jupiter 9 85mm f/2.0 and Jupiter 11A or 37 135mm f/4.0. A dark horse in this is Carl Zeiss Jena with the black 50mm f/2.8 standing out. All of these are M42. Also a lot of low budget commercial stuff uses old Canon FD.
For M42 and FD on crop sensors like those on E-mount and EF-M cameras there are now focal reducers. (About time too for Canon EF-M, my EF-M to M42 focal reducer is now in the post from China)
How many people really notice the difference between 3K and 6K?
"The best zoom lens is your legs." - Ernst Haas