If you're new to photography, you might have heard of ND filters, but graduated ND filters might be something foreign to you. This great video will show you what they are and why they're so useful for landscape photography.
Coming to you from Landscape Photography IQ, this helpful video talks about graduated ND filters and their usage in landscape photography. Graduated ND filters are similar to ND filters in that they contain material that limits light transmission, but they differ significantly in their usage. Whereas a normal ND filter is used to prolong the exposure time, a graduated ND filter is used to compress the dynamic range of a scene by lowering the highlights. This is especially useful in landscape photography, where one often encounters scenes with dynamic ranges that exceed the capture capabilities of even the most modern sensors. While you could also bracket such a scene and blend the exposures in Photoshop, using a graduated ND filter allows you to get the entire scene in one shot, thus saving you a fair amount of time in post-processing. If you frequently photograph such landscapes, it's worth considering picking up a set. Check out the video above for the full rundown.
For me, grad ND filters are an absolute go- to option when there might be some heavy movement in the frame (i. e. lots of tree branches, birds, even clouds during long exposure)
Exposure stacking might be a thing, but removing ghosting from a gazillion branches isn't as much fun as it used to be.
Side note: circular ND grad filters are about as useful as an inflatable darts board. Imho. Unless, of course, you always want to run your horizon line smack down the middle of the frame. Just sayin'
An inflatable dart board may not be practical but it'd be a lot of fun... until you hit it! :-)