Generic/Leica Shades and filters
I've standardized my filters at 46mm because that is the largest diameter filter that I'd consider purchasing. I currently only have 50mm lenses (40mm, 43mm diameter Canons/Nikkors) and I just adapt to 46mm and use a generic shade because finding 40mm/43mm filters/correct shades can be tricky and pricey.
I'm thinking of purchasing some Leica lenses that are 39mm in diameter. The filters/shades are a bit more common so it is more practical for me to purchase the shades/filters. I do not use that many filters so it won't break the bank, but shades are expensive, and I'd rather consolidate accessories.
Is there any practical disadvantage for stepping up? I figured that the worse case is vignetting from the shade and viewfinder blockage.
I also figured that any deviation from the appropriate shade is a case-by-case so these are the lenses I'm interested in:
-35mm Summicron V1
-50mm DR Summicron
Any experience with the generic heavystar shade and any advice on a not-too expensive Leica shade to cover these (incase heavystar isn't the best choice).
Generic 39mm screw-in shades are cheap on eBay.
As long as a cheap shade screws in (not a particularly common problem, but I guess it's possible for any manufacturer to have an off day), it will be fine. You don't have to pay extra for the Leica optical air inside it . If the venting isn't super-nice, grab a needle file and a can of flat black model paint for touchups when you are done.
I pretty much did the same thing; standardized on 46mm filters. Thankfully, most all of my lenses are 46mm.
eBay is your friend - no shortage of cheap adapter rings, hoods and caps.
Though for the 39mm lenses, it might be worth it to get those filters you used most in the native (39mm) size. Filters this small are pretty cheap and you'll be able to maintain one of their biggest draws - small size.