iPhone 5 & Panoramic picture taking. Am doing this right

I'm new to apple so, Hello all!

I've been messing around with the panoramic feature of iPhone 5. 

When I start the picture I see the arrow and the line and I understand that you have to keep the arrow on the line as best you can.  I can take a picture and I do get a result.  However what I don't understand is how long the picture can be.  So far I have only been able to take a picture that is as long as the phone screen is wide.  In other words I go outside, start the process facing left, then pan 180 degrees to my right and stop the process.  All I end up with is the start picture stretched (not distorted) to fit the screen's width (a normal 16:9 picture).  I can take a normal picture (normal dimensions, normal camera settings ect.) showing the same image.  It is as though the phone is ignoring all but the first picture or cutting everything after the first picture.

I've tried slowing way down when panning.  I tried incruments of speeding up to the point where the picture was all distorted.  All the attempts result in just the initial start point picture.

How long can the picture be (time/length/MB or bits/dimensions)?  If it can be a lot longer than the result I'm getting what am I doing wrong?  Should this be just as simple as starting the process - ending the process and then viewing the result regardless of the length/width of the picture?