ARCA SWISS Monoball p0 with Panning System and 1/4" thread,

This is, in essence, an upside-down ball head, which is what pistol grip heads are. This is great when you need to get a level shot (landscape photo) but you're in a precarious place and you're tripod legs cannot be moved (think rocks in the middle of streams, uneven terrain, etc.). I don't have to move my tripod legs an inch to get level -- these types of heads have that built into 'em without having to fiddle with multiple knobs!But while the pistol heads are heavy, this thing is incredibly light! I've used it backpacking, and it's nice to have something that's 9.9oz (on my scale) that can handle a full-frame dSLR with 1.6lbs lens without a problem!The "knurled" ring around the mid-section that replaces knobs is genius, but does it work in the field? Yes! Took it on a backpacking trip, had no problems at all. Arca Swiss is reputable company, I expected this level of craftsmanship.PROS- Lightweight!- no knobs- slender profile (hang it off a pack on sticks, it doesn't snag)- easy to adjust- panning feature stay level without having to level tripod- solid materials- locking stress distributed evenly (not a screw holding the ball in place)- ball underneath, less dust getting into mechanismCONS- pan lock lever not strong in appearance; will it break?- sorry, can't think of many

I used this for the first time going to Banff in the winter. Temperatures dropped to -14 below Farenheit.at around 0 this ball head starts to freeze up and get almost impossible to move. If you are looking at really cold locations, find a different product. On the plus side, when it worked, it worked great. I love it and will continue to use it for a very long time.

While you can adjust ball tension via the single large ring, you can't do it with much precision. And since there's no tension limiter you have to find your ideal tension setting every time you make an adjustment instead of being able to dial in a repeatable setting.The panning tension adjustment isn't as controllable or smooth as with my other ball heads. The ball is small compared to competing ball head designs. That means that it's more difficult to adjust tension for smooth operation with heavier equipment. The main ring's operation isn't very smooth and there's play in the ring assembly.The Arca quick release clamp for this head lacks a bubble level. The lever action is fussy with two separate interlocks that you need to operate to open the lever part way and to fully open it. And the mounting screw that came with my lever action clamp was too long. It scratched the ball's surface and I had to remove it, grind it down, and reinstall it.What this head does well: Panning action is right under the camera so you don't need a separate leveling action and can set up fast for panoramic stitch series shooting. The sleeker design makes this head easier carry without snagging and the head is compact. The panning lever doesn't reflect the clean design, however. Its design makes it into a small hook.I wouldn't recommend this head for heavy camera and lens combinations. It's better suited for a lighter carbon fiber tripod setup where you favor a light, sleek, setup and don't need rock solid, precision control.

If you set enough tension on the head to hold your camera in place when you let go, it's still very smooth. locking the head down (turn the big ring further) does not disturb camera position.It gets stiffer as you move from center, which would be the ellipsoidal ball in action. I'm not convinced this matters to anyone not using a lens heavy enough to need a gimbal. I've nothing longer than 300mm/variable.If you are not looking to commit 100% to A/S's new plate system, this is the one you want. The stud comes out, is actually an M6 x 10 countersunk screw with a 1/4-20 stud milled onto the top of it. You want an 11mm thin wall socket to remove it. Be careful you do not use a screw that's long enough to touch the ball. They used something like vibra-tite to hold that double ended screw, which means it'll be hard to tell if your screw touches. Measure the screw in place on the clamp you plan to mount (measure the length that's going to go into the head). You are probably safe if that's 15mm or less. Different clamps are different thicknesses. Be aware of this if you switch clamps.I've also read that that plastic washer can be removed when mounting a clamp with a screw. I have done this. Details in a comment to this review.

This is the best ball head I have used.I can't believe how light it is and how strong the grip is. No droop when tighten it, it stays right where you put it.I am using a SunwayFoto DDY-60p0 Discal Clamp on it and it works great.