How to interpret blue lines that show motion in Program Manager

[JonMack]

I have always been puzzled by the blue lines (straight or curved) that appear when I'm editting video.  I cannot find documentation on what information these lines show me and what they are guiding me to do.  I'm do a lot of zooming and focusing on particular moments in a long video (in this case an hour and a quarter long play).  What makes them appear? Why do they seem cumulative in a give editing session? What about them tells me what I need to consider in order to make cleaner and smoother (or sharper and more abrupt in cases where that is appropriate..) This is likely to be too complicated at topic to consider here, but I would appreciate direction toward a good explanation of the purpose and use of what are sometimes called "motion guides," 

[R Neil Haugen]

I have no idea what blue lines you are talking about.

The "safe" lines if you have Overlays on are always a rectangle of the 'safe' inner area of the screen for graphics.

Reference lines are something you can add to the program monitor, but again, they are straight lines across the screen.

I've never seen any curved or movable blue lines in the program monitor. So a screengrab would be most helpful.

[Ann Bens · Accepted solution]

A blue curved line usually refers to a motion path

https://helpx.adobe.com/premiere-pro/using/motion-position-scale-rotate-clip.html

[JonMack]

Thank you Ann.  You've pointed me in the right direction.  The documentation, however, does not give any practical guidance on making use of the guides.  I know they are there to provide guidance to jolting changes when they are not desired, as in moving from one portion of zoomed in clip to another, but it gives no clue on how this might be used practically.  E.g. what is aspect of the line that alerts an editor to a problem?  The example in the link doesn't really spell out how to make effective use of the information.  This is the information I'm hoping someone who's worked with the motion path guides might provide or might direct me to a source that goes into their use in more detail than the user guide page. 

[Ann Bens]

Might want to read the whole chapter.

It explains how to move an image along a curve.

[JonMack]

I had read the article.   In the clip I'm editing, I want to go from a distant shot to a two-shot.  What are the motion path guides telling me? What tells me I'm make the change smoother or more jarring? 

Here's an example of one such guide.

 

[Ann Bens]

I have no idea what kind of motion it represents in this particular shot.

All it shows you are going down and up again.

To make things smooth you use bezier keyframes.

the guide is for one clip only: it does not overlap from one clip to the next.

Practice on a static color matte first and get the idea behind the guides.