85mm lens for shooting indoor sports?

I've seen several threads that mention using the 85mm f/1.8 for shooting indoor sports but no mention of the 85mm f/1.2L. I was wondering if this was simply due to the fact that the f/1.8 is so much cheaper or if for some reason (i.e. depth of field at f/1.2), the f/1.2 isn't well suited for this application.

The main reason is that the 85mm f/1.8 is blessed with a very fast focus mechanism. The 85mm f/1.2L isn't. High focus speed is important for indoor sports.

For indoors, your best bets are the 50 1.4, 85 1.8 and 135 f/2

The 85/1.2 would be great for sports like weightlifting where the subject does not change position much if at all. For all fast action sports it is not very good at all.

The 85/1.2 has the slowest autofocus speed I have ever encountered to date and reports indicate it is the slowest period. The manual focus is also not well suited to sports action shots.

The 85/1.2 is a portrait lens and an extremely good lens for that purpose. But an action lens it is not. However, if you can get around its focus speed it would be a great sports lens for that range.

Thanks for the explanations. I figured that there must be something along those lines. I had been told that the f/1.2 version was "the" portrait lens. It would be easier to justify buying (to my wife that is) the 85/1.2 if did double-duty for indoor sports and other activities. My daughter dances and the theater is usually dimly lit and flash photography is not normally permitted. But if the focusing is that slow, it wouldn't be well suited to that application either.

It might not be so bad for dance. Indoor sports has an inevitable, and unpredictable amount of back and forth at highish speeds; Action in dance typically 1) is more predictable and 2) displays less linear speed, so the slower focussing may not be as much of a problem for that. Of course when your daughter shoots up to 6'5" and thus is "too tall" for dance so she takes up basketball, it won't do at all.

I would recommend the 85 f/1.8 for dual purposes of portrait and indoor sports. The f/1.8 is still a pretty good portrait lens plus it's much easier for indoor sports.

I don't own a 85mm f1.8, but I'm eager to have one for its super speed and light weight. I took pics in a squash competition with a 50mm f1.4, where the ISO was stepped up to 800 and shutter speed at 1/250s. The f number fluctuated between 2.8 and 2, and occasionally below. If I had used my 100mm f2.8 macro, I'd have known how difficult to take indoor sports pics with a lens slower than f2.8. Therefore I believe the 85mm f1.8 must be a great tool for such dim light environment with demand in shutter speed. The 85mm keeps you a decent distance from the subject, which is also very fine in portraiture.