I know that some people here attach their camera directly to a tripod, either to a plate on top of the legs that is flat or to a plate, from the film/video world, that provides about 15 degrees of leveling function. As I understand it, at least one person - Christopher Broadbent - uses a Novoflex Panorama Plate on top of a leveling plate to get a panning function.
I happen to use the Arca-Swiss system for 8x10 and 4x5. A few weeks ago, I decided to attach a 50cm rail that telescopes to 75cm, and front and rear function carriers that fit both the 8x10 and 4x5 standards, directly to the flat plate of my tripod (a carbon fiber tripod made by Gitzo, model 1325, that supports 26.5 lbs). The effect of this is that the tripod, rail and function carriers are now one piece, and when I set up for a shot, I use a level to level them as one piece. Then I slide either the 8x10 or 4x5 standards/bellows on to the carriers depending on which format I want to use.
I have come to the following conclusions:
1. The cameras feel much more stable and I have gotten rid of a few pounds - I am not inclined to go back to a traditional pan and tilt head;
2. I need to be able to level the tripod and camera, either by shortening/lengthening the legs in conjunction with a level, or with a leveling base;
3. I need to be able to pan the camera after the 8x10 or 4x5 standards/bellows have been mounted (panning using the tripod legs at that point is problematic, and the Novoflex looks attractive);
4. I do not, for the photography that I do, need to tilt the camera forwards or backwards.
On the few occasions that this subject has come up on this forum in the past, there has been a tendency for people to say that they can't imagine anyone taking photographs without the tilt function of a pan and tilt head. On that issue, and for the purpose of this thread, please see #4 above.
I would appreciate comments from people who are not using tripod heads on how they are dealing with leveling and panning, including any gear recommendations they may want to make. I'd also appreciate a recommendation for a good level (e.g. Starrett 98 6", something else?). In a thread a couple of years ago, Drew Wiley talked about a "self-leveling angle finder". A Google search has left me none the wiser about what this is. So, what is it?