Off the top of my head (this is not a definitive list), the only Canon first-party lenses which do it are the 85mm f/1.2 and f/1.4, 200mm f/1.8, and the FD 50mm f/1.0. The 400mm f/2.8 does technically do it, too, but you'll never see it with that lens because of how strongly everything it flattened out. Rumour was back in the day a 135mm f/1.4 was prototyped and never moved forward specifically because the image circle was so cut up and shaped by the lens mount. (Remember, usually these things are caused by the lens mount, not the mirror box, so calling it "mirror box clipping" is, in most cases, inaccurate.)
I've never seen or been aware of any Sigma, Zeiss, Tamron, or Tokina lens doing it, though given how many third-party lenses there are out there, I wouldn't just assume that every third-party lens is in the clear.
Nearly all anamorphic lenses will do it.
2) How does one get round/soft/large bokeh balls from a large aperture lens? Just stop it down and forego the size/softness of the large aperture to eliminate the clipping? (Wouldn't that defeat the point of buying the fast lens?)
Same way you always do:
- Stop the lens down, reducing the image circle to within the limits of the mount (or other obstructions), and trust the aperture blades are numerous and rounded enough to stay looking circular. Two stops is usually enough.
- Spend a lot of money and reduce light transmission greatly by installing an apodization filter on the rear element of the lens. (Look up the Fujifilm 56mm f/1.2 APD and Sony 100mm f/2.8 STF.)
- Frame your shots wider than you otherwise would so highlights stay closer to the middle of the image circle, and crop off the edges.
- Reduce contrast enough that there is no shape at all to anything out of focus.
- Use diffusion/bleed/mist filters so every highlight spreads out and hope it covers it.
- Use old (pre-1982, as a general rule) lenses which usually have lower contrast and soft diffusion as inherent characteristics, covering problems like this.
- Photoshop it.
Or, finally,
- Ignore it and stop thinking about it, because nobody who looks at your images will care. The person taking a photo—you—is the only person who cares about 'bokeh'. Your subjects don't care: if they're a person they're only looking at themselves; if they're not a person, they're not looking at all. The people looking at your images don't care; they're looking at whatever is in focus. The vast majority of large-production movies ever made use anamorphic lenses which always clip the lens mount, and nobody is missing out on winning an Oscar because some inane, blurry blobs in the background of a shot had their top edges clipped off. (This is also why 'catseye' background shaping doesn't matter, no matter how many SLR lens reviews waste time on it; anamorphic lenses shape
all out of focus highlights in that way, and you can guarantee that nearly all of your favourite films were shot with anamorphic lenses.)
If it really bothers you, and you really want to get a completely circular look with a lens fully open, pick up a Sony or Fuji camera, as they're the only brands producing apodization lenses for public purchase. Otherwise, don't worry about it. Bokeh—let alone bokeh
shape—is one of the last things any viewer looks at or spends a single second considering. The 85mm f/1.2 has had clipped highlights for decades now across both versions, and it's not very sharp, has horrific aberration, some unflattering barrel distortion and terrible focus (both auto and manual), yet it's still 'the' Canon portrait prime lens because none of that stuff, even all added together, matters anywhere near as much as the overall rendering.
(And I say this as someone who does have and use the two aforementioned Fuji and Sony lenses. The amount of times they've actually been useful and the effect has actually matter can be counted on one hand.)
