Looking at the answer on How do I take pictures of planes flying at an airshow? I see that many of the shots have blurry rotors. I'm currently shooting at (210mm (1.5x crop), ISO 100, 1/800, f8). A sample shot is listed below.
From the related post below, an ND is suggested to create motion blur. I'm curious if a CPL (I don't have a ND yet) will do the job or must I use an ND? Assuming I do buy an ND filter, is there a "recommended" n-stop to get, if you don't have a particular goal in mind?
How to create motion blur in daylight?
Use ISO 100 and about f/8, maybe f/8-f/11 if you're ok with the results. Polarization has a large impact if you're switching from landscape to portrait or vice versa. A polarizing filter does remove 2-3 stops and helps quite a lot in that regard. If you can live with the odd background/water changes then it will work fine. Otherwise get a neutral density filter. One side note, did not get any glare form the nearby bay, since polarizes seem to take care of that so not have a hood isn't a big problem. (I was using a step-up filter
Hope this helps everyone.