The best way I can explain this is:
Frame Rate is how many frames per second.
If you want to shoot 60 frames per second, which means taking 60 pictures every second, every 1/60th of a second your shutter opens & closes
Shutter speed is how fast you take each picture or how long the shutter is open
if you do this at 1/8000 of a second each time, you leave huge gaps between pictures (7860th's sec) and the playback looks choppy or jello'd
180 shutter is when your shutter speed is twice your frame rate (or close to 2x),
this leaves much smaller gaps between pictures, which is what we refer to as motion blur
This is the preferred way to shoot for cinematic look.
If you want to show your footage in slo mo, having the proper shutter speed will help tremendously.
You can play around with the settings and see what you like, but there's very little room to argue against proper ND's
Using the proper ND for the conditions, allows for much better protection of exposure (highlights & shadows, or whites & blacks)
ND's can best be explained as sunglasses for your camera
just like us, when it's bright out and you slip on sunglasses, you can see more detail, if they're strong enough ND
Put the proper ND on your camera, and the detail comes to life
Picking proper ND, I use the sunglass technique and look thru the filters until one shows most detail to my eye, might be right, I'm not sure, but my footage is much better that way
Check out my youtube channel, Primo _NYC (there's a space between the o & _ )
I shot some high speed cruisng on a Lake with a Malibu Wakesetter with Rennat's ND'S (
)
and some slower speed wakesurfing with stock ND (
) and the detail is much better with the ND32 on a bright day, very evident on the back pad of the boat, can't see the grey detail with the stock filter at all
Good luck, have fun!!