ND filters with polarizing?

[SHRED]

OP: What is your goal? Stills only? Video Only? or Both?

Both

 

[kilomikebravo]

Shred: OK, cool. The stills question is a no brainer, using either Auto or Manual exposure and you'll get the best images if you shoot in RAW vice JPG. Simple and no ND filters required unless you decide to try shooting long exposure photography. Then you'll need some REALLY dark filters with big numbers. The biggest issue with stills is often focus so I use the option to have red lines on edges that are sharp. Be sure and turn Auto Focus off and only use Manual for your videos. At least that's what I do.

Video is different and the opinions on whether "cinematic motion blur" is preferred are mixed. If you're in the camp of the supporters of CMB, then you will need ND filters, (8, 16, & 32) will get used more than any other so I would start with those three. They are necessary because you would like to be able to select the sharpest aperture (f4-f5.6 is generally accepted as the best range,) but in bright daylight, selecting that aperture range will cause the video to be way overexposed and the only option other than ND filters is to raise the shutter speed until you get near 0ev. This typically results in shutter speeds around 1/200 and often a lot higher. This combination again is generally accepted to produce very sharp video, to some almost unnaturally sharp. I think the same situation exists for soap operas and we all know how fake they look. Hence Cinematic Motion Blur and thus the need to maintain a shutter speed where the denominator is double your frame rate. NOW, you select the proper ND filter that will give you near 0ev exposure at f4-f5.6. All this before you takeoff. Many filter manufacturers use the generic rule of thumb...

Cloudy: ND8
Partly Sunny: ND16
Bright Sun or Snow: ND32

With the aircraft camera pointed in the direction you plan to fly with the aircraft sitting on a table or some other flat surface, dial these settings in and figure out which ND filter you will need. PolarPro has a great app that lets you input the data you have for 0ev without a filter and it will tell you the filter to use based on the numbers in your "Golden Triangle," i.e., ISO, Aperture, and Shutter Speed. it works great and saves time but the truth is, after some time using them, you'll get a very solid feel for which one you need just by instinct. Much like the gimbal cover and ND filters, they all get easier to install after some use. Sometimes though, you guess wrong and either have to step up or down with the next filter.

I don't know if any of that will be helpful but I hope so.