This one cool Slider/Dolly Technique...
 

You see those shots that look like the camera is moving from left to right, perhaps looking at a person, and the camera pans as it moves across the dolly or slider to keep the person perfectly in the middle?

How do you do that without the person shifting left to right a little bit?

See this:
(as the camera moves left or right, the operator pans the shot, but how do you get such a good pan?)

-------------------***Camera looks here at person



<-------------- |Camera| ------------->
================================Slider

Re: This one cool Slider/Dolly Technique...
 

My solution for this is a ride-on dolly. If the camera operator is travelling on the dolly, then they are free to pan as smoothly as they would if stationary. This goes vertically as well on my ride-on crane. I can swing my crane all over randomly and the operator riding on it can keep a subject centered in the frame.

Re: This one cool Slider/Dolly Technique...
 

I use that technique with a slider and fluid head. You can see it in action at 2:37 of this video

If you have a center marker on your viewfinder (or some other non-moving visual reference), it's easier to pull off.

Re: This one cool Slider/Dolly Technique...
 

Yes I was putting a mark on my 5D viewfinder and that was helping, also making the panning knob tighter on my tripod head helped too so that the panning was more controlled. Its really dificult to try to slide a slider and pan at the same time though, and walk with the slider. Oh and focus too. (:

Re: This one cool Slider/Dolly Technique...
 

I do this with my motion control rig. I created a feature in my software called auto track, or lock target. Here's how it works.*

Use the controller to position the camera, point it at some and focus the camera. I use either iPad or laptop.*
In my software, check the lock target checkbox.*
Use the iPad, laptop or physical controls to position the camera on the linear track

That's it. The subject will stay perfectly framed. The result of this effect is that the background appears to "rotate around" the subject. Also keep in mind that my motion control rig will not only pan and tilt to keep the object framed, but will also keep the object in focus. This is practically impossible for a human operator to do manually. Perfectly performing pan, tilt, focus and linear moves manually would be very difficult.

My motion control rig will, even while performing ramp up and ramp down of the linear motion. Here's a quick video demonstrating this concept with my rig:

http://db.tt/kn57EdNA

and here's a blurrycam shot of the actual rig while it performs the move.*

http://db.tt/rmbwr5Jd

Keep in mind that this was done with my 4ft track. My 10ft track makes even bigger moves.*