Soooo, honestly I totally feel you on the anxiety!! Spending that much on glass is terrifying, right? I mean, Leica glass is basically like jewelry lol. Since you're worried about the budget but still want top protection, I would suggest looking at the B+W 39mm Master 010 UV-Haze MRC Nano. It's seriously the best balance of price and quality out there. I'm kinda new to this too, but I've been super cautious and did a lot of research. Basically, the Master series is their thinnest mount, which is highkey important for your 35mm Summicron because it wont interfere with that rectangular hood or cause any wierd vignetting. The MRC nano coating is the real hero here—it actually makes the glass repellant to water and dust. If you're out doing street photography in the rain, you can literally just wipe it off with a cloth and not worry about smearing. Wait, I should mention that while Heliopan 39mm Digital UV SH-PMC filters are great (someone mentioned them earlier!), they can be harder to find and sometimes pricier. The B+W is a safer bet for your wallet. Honestly, unless you really want the Leica logo on the rim, the Leica 39mm UVa II Filter (Black) is hard to justify when the B+W performs just as well for half the cost. Just be realy careful when screwing it on... I always get so nervous about cross-threading those tiny 39mm threads!! TL;DR: Grab the B+W 39mm Master 010 UV-Haze MRC Nano. It fits the hood perfectly, has amazing coatings for rain/dust, and is way cheaper than the Leica brand version. Good luck with the new lens, it sounds amazing!!

hey man, congrats on picking up the Leica 35mm f/2 Summicron-M ASPH Lens!! that thing is a total masterpiece, but I honestly totally get why ur nervous about the front element... those repair bills are no joke lol. I have been shooting M lenses for over a decade now and Ive tried basically everything to protect my glass without ruining that famous rendering and contrast. In my experience, I would suggest sticking with the Leica E39 UVa II Filter. I know they are pricey, but honestly, the mechanical fit is where they really win. Since you mentioned the rectangular clip-on hood, the Leica filter is literally designed to have the exact same outer diameter as the lens barrel so the hood snaps on perfectly without any wiggle or weird gaps. Plus, the glass quality is top-tier so you wont see any drop in micro-contrast or sharpness in your street shots. If you dont want to pay the Leica tax, the B+W 39mm MRC Nano 010M UV Filter is probably my second choice. Their MRC nano coating is actually amazing at shedding water and dust, which is great for street photography when you are caught in the rain. But... I have noticed that sometimes the B+W frames are just a tiny bit thicker or have different knurling, which can make the hood fit a bit tight or feel weird when you are mounting it. I have also used the Heliopan 39mm SH-PMC UV Filter which is great glass, but they can be harder to find in stock sometimes. I havent noticed any ghosting with the Leica or B+W ones, but definitely avoid the cheap stuff cuz it will definately flare like crazy in backlit shots. Anyway, hope that helps u out... let us know what you end up going with!

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