Understanding filter-thread size

[YuengLinger]

Filter-thread size seems to have increased on a few Canon lenses over the years. I'd appreciate if members with enough understanding of lens design could explain why there is such a variety of sizes.

A little speculation on the filter-thread size of the rumored 50mm 1.2L II would be fun too!

 

[Loswr]

Bigger front elements on fast aperture wide/standard zooms to reduce aberrations. (vignetting, distortion). Telephoto lens designs already have the largest front element feasible, since the entrance pupil is effectively at the front element rather than being within the lens. Prime lens design is simpler - I can stack three F-Pro filters on my 35/1.4L with no increase in vignetting.

I bet the 50L II has the same filter diameter as the current lens.

 

[privatebydesign]

For a long time the L primes were 72mm and the 2.8 zooms 77mm. This wasn't wide enough for the newer designs so it migrated to 82mm for the two shorter 2.8 zooms.

Now we have a choice of 52mm, 58mm, 67mm, 72mm, 77mm, and 82mm which are all used by Canon, with 72 and 77 being the obvious front runners.

I'd still think 72mm would be the best bet.

 

[Loswr]

Now we have a choice of 52mm, 58mm, 67mm, 72mm, 77mm, and 82mm which are all used by Canon, with 72 and 77 being the obvious front runners.

Also 43mm for the EF-M 22/2 (I already had a 43mm CPL for my Vixia HF M41) and 55mm for the EF-M 11-22mm.

 

[YuengLinger]

Thanks. I had a perception a bigger front element was better, because L primes tend to be bigger than their standard counterparts.