Polar Pro ND Filters - Easy way to select right one to use.

[RedSoxFan42]

I just received my Polar Pro Filters. I ordered the custom set giving me the ND4, ND8, ND16 and ND32. Concerned about figuring out which one to mount on my M2P I decided to try this method. On my iPhone 8 I downloaded the app named Light Meter. (see image). Holding my phone towards the outside where I will be flying, I see that if I want to shoot at an aperture of 4 and ISO at 200 , I would need to set my shutter to 1/1000. If I am shooting at 30 FPS, I should use a shutter speed of 1/60. By placing the ND 16 filter in front of my iPhone camera lens, the app now reads aperture of 2.8, ISO 200 and shutter speed of 1/60. How accurate will this be, well I need to do some test runs, but don't see why it wouldn't be fairly accurate.

 

[brett8883]

I just received my Polar Pro Filters. I ordered the custom set giving me the ND4, ND8, ND16 and ND32. Concerned about figuring out which one to mount on my M2P I decided to try this method. On my iPhone 8 I downloaded the app named Light Meter. (see image). Holding my phone towards the outside where I will be flying, I see that if I want to shoot at an aperture of 4 and ISO at 200 , I would need to set my shutter to 1/1000. If I am shooting at 30 FPS, I should use a shutter speed of 1/60. By placing the ND 16 filter in front of my iPhone camera lens, the app now reads aperture of 2.8, ISO 200 and shutter speed of 1/60. How accurate will this be, well I need to do some test runs, but don't see why it wouldn't be fairly accurate.

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Yea you have the right idea but the light levels on the ground are usually different from the light levels up above so you usually have to fly up to check the readings and then come back down to put on the filter. Polar Pro actually has a free app designed to do just that and more explicitly is designed for exactly what you are doing but instead of reading the light levels directly you input the automatic settings from the “test flight” up.

There’s also an element of experience. The adjustable aperture on the M2Pro adds an addition element of complication but for my Mavic Pro I know that if the sun is visible during the day it’s gonna need the ND32. During the second half of golden hour (or first in the morning) is the only time on a sunny day I need the other filters.

When my exposure starts dropping enough that I feel I need to adjust ISO above 200 is when I know it’s time to switch to the ND16. The ND16 usually gets me all the way to dusk when I need to remove the filters completely. There’s just such a short window of time for the ND8 or ND4 that it’s usually not worth taking the time to switch them out. This is when you get some of the best light so taking that time can mean missing it. If I’m already in for a pit stop I’ll change to either the ND4 or ND8 but I almost never use both on the same sunny day.

Cloudy days are trickier because even though it looks dull and gloomy the light can just be diffused not diminished so that’s when your light meter will come in most handy. Still an element of guess and test though.

 

[Mossiback]

General guide with ISO at 100:
• ND4 - sunrise/set
• ND8 - cloudy
• ND16 - sunny
• ND32 or 64 - bright sun on sand or snow

You can use this as a starting point then see what works for you. Filters are only needed for video, unless you want a slow shutter to induce motion blur in photos (water, car lights, etc) or are using a polarizing filter to cut reflections.

 

[CirrusNine]

Mossiback - thanks for the ND general guide. Can't wait to try the filters out.