Frame Rate and Max Frame Rate in Record setting page

[chaosui]

When we do not use the common resolution but use other values, let's say 384x136, I find the FPS=40.86 while there is a max FPS =50.I get confused about why there are two FPS? Does that mean with a specific resolution, there are two different FPS for us to choose? The default FPS is the one 40 and we can get FPS=50 with a smoother video by choosing the max value? How do I know which FPS is the one for current setting?

[Nikon1]

can you post an Image of that?
 could that be record Time in Seconds you are talking about?

[chaosui]

I figure out the solution. When we change the resolution, always pressure the Max button such that it is clear to see that we are using the max FPS for the current resolution setting.