a.noctilux

this may be posted here this thread

If you use one of manual M or LTM/R (not R8/R9 though), but if you happend to use one of more modern film camera (with AF other brand than Leitz/Leica) batterie is a "problem". One good thing with M240 and family, SCL2 batteries are not dead yet with my many M which use those huge (immortal in my use) batteries. For peace of mind and experiences from other cameras which use batteries, I have some spares (needing some care).

Yes of course. I might add that in my use, before using the M with 75mm framelines. That was my use many years, before acquiring M4-P/M6.

Seen this ...

As side note, The 1.4/75 was first used on M without 75 framelines, as M4/M5. This may have some importance .

As old user of 75mm, I see that the huge 50 framelines coupled with 75 brackets are good things. In my pov, those aid in framing and I rarely "see" those 50 framelines when I use 75mm lens. I use for many decades Summilux-M 75mm and Apo-Summicron-M 75mm on M6/MP/M-A. The first 75mm protrudes a lot in 75mm framelines, while the last one is just fine. While using a while, those quirks became "aids".

Singapore ?

Noname hood. Many years back, I went to Bièvres , Rencontres photos, every year early June, my favorite pastime. I went there with the lens, then took time to find the hood (with many things, of course) with a sheet of paper with a list and measurements of the bit I was after. The hood has no reference or marking, sorry. It mounts from the outside of the lens by friction, 42mm. No vignetting at all.

Just for fun size comparison R/M "same lens" ...

Depending on which one, two ways to accept the 1/4 and 3/8 thread sizes: - on one you need to unscrew the head to screw-in the other thread size, so one in 1/4" and the other is 3/8" - on the other there is collapsed bigger thread which protude when in use and with smaller thread will collapse in the head. Have a look at KGOON and/or 14115: like here in Wiki the last two at right here for example:

@BenMathes You are tricked by the SLR's VF polarized light ? I bet you use this type of lens, Transitions® XTRActive® Polarized™ I had some weard vision when I wear polarised sun glasses ( Rayban P in my case) and the weird vision became normal with non polarized sun glasses. In the viewfinder path of SLR or M some polarized effects are used and with polarized glass, maybe this is what you saw.

Yes, not to overthink. Just use the device and/or use another device (lens/body ?) if available.

In Wiki I see 100 SL made in 1974, in this range of your Leicaflex SL, have a look here ... 1386001~ 1386100~ Leicaflex SL 1974 100~

First question to the OP, on which camera this lens will be used. I ask because this lens is very nice but old style, version I that I never use is different concept than the II. It may not be suitable for digital use, I tried on Sony 36Mpix and that was not a success, wide open. I use happily with film on my R and Leicaflex SL (in this case wide open ...) and the lens is quite good wide open. Anyway, the resolution is enough for most films I use, no complaint. Maybe you can see in Wiki tech data in pdf : again from Wiki

Stretching to 28mm for me with Tri-Elmar-M 28/35/50 nice having choices in one lens, not even zoom style . As side note, lenses are there to be used, so the focal length choice is not a free choice.