I’m a big fan of the Arca Swiss C1 Cube. I don’t particularly like their D4 geared head, though. After using the C1 for a while, I find ball heads imprecise and unpleasant to use. However, the C1 can take a while to set up. I tried a combination ball and geared head a few years ago, the KPS R&D T5, and just hated it. So I was a little worried when I ordered the P0 Hybrid. Here it is in all its glory:
At the bottom is an inverted ball head. twisting the big knurled ring that circumnavigates the base tightens and loosens the ball. On top of that is a geared section that controls pitch and roll. On top of that is a ungeared platform for adjusting yaw. In the above picture, you can see the yaw and roll control knobs, one coming out of the head towards you, and one pointing to the right. You can also see the knob for locking the camera to the head. Note that the knobs all look similar. I can tell you that they feel similar, too, even though the knob that tightens the camera plate is slightly larger and the knurled section is longer than the roll and pitch knobs.
You don’t want to get those three knobs confused. You especially don’t want to twist the knob that holds the camera in place while thinking that you’re adjusting roll or pitch, especially if you don’t have fast reflexes so you can catch the camera before it hits the ground. More on that in a minute.
Here’s another view of the head:
Now you can see the rounded triangle that unlocks the yaw platform. You’ll see that in both images above, the head is set up so that all four controls stick out in different directions, each having its own compass point as you look straight down on the head. I suggest that you set up your head the same way, and keep the knobs pointing in the same direction with respect to you every time you use the head, so as to minimize the possibility of confusion as to which knob is which. I set mine up with the knob that tightens the camera plate down pointing towards me. That way it’s the hardest knob to reach, and I can see the roll adjust calibrations from the back of the camera.
Now look at the picture above, and note that the pitch axis (assuming you’re not using a lens with a tripod collar) is raised (or lowered, depending on which way the camera is mounted. I can tell you that it is raised as far as it will go, which is nowhere near as far as the extent of the geared movements in the C1.
The practical implications of the limited amount of geared movement are twofold. First, you’ll want to center the geared axes every time you finish using the head so that you don’t run out of geared range the next time you go to use it. In this respect, you treat the head the same way you’d treat a view camera: always return the device to a known state when you’re done with a shot so you will know where it is when you’re setting the next one up (I don’t do this with the Cube, which has a much greater range). The P0 head provides indices to show you when the movements are centered; you can see the one for pitch in the top image above. Put the two dots on the two furthest ticks and you’re there.
Why not center the movements just before you set up a shot? Because you’re much more likely to be in a hurry then.
My biggest problem with the head is the lack of a yaw axis underneath the ball. The C1 has yaw both under an on top of the other two axes, and that is very handy. I’ve added a RRS panning base underneath my P0 Hybrid to get the same function that the C1 comes with, but that negates one of the great advantages of the P0 Hybrid: its small size and light weight.
I’d give it a B, or maybe a B+. It’s certainly better than a ball head for what I do, and it is faster and — I expect — more rugged than my C1, even if it’s not lighter with the panning base added.