Let me start by saying I'm a newbie to drones, but I have almost 50 years experience in photography.  I've viewed some videos on the use of ND filters that "showed" how using more dense filters resulted in darker images. Sorry, but that is not a true representation of why to use ND filters or what happens when you use them. If your exposure settings are "automatic" then the resultant images will be the same, regardless of which ND filter is used. The most informative post (wish I saved the name) was using ND filters to adjust shutter speed or apeture to produce a desired effect. The attached image sequence shows that the same "exposure" is obtained regardless of using an ND filter or not. The post I read suggested that you should use a shutter speed that is at least twice as fast as the FPS you're shooting. That may be a good rule-of-thumb for a starting point, but different situations may require tweaking the settings.

I may be wrong here, but you appear to be relating the use of ND filters to still photos. While there are some situations where they might be beneficial to stills, the main reason for the use of ND filters on the Phantom aircraft is for video, specifically the earlier P3 and P4 aircraft that had fixed focus, fixed aperture lenses.

The idea is to introduce some blur to the frames by getting the shutter speed down to twice the frame rate. This has the effect of hiding the staccato effect of low frame rates by using the resultant blur to soften the transition from frame to frame. Shutter spee3d was the only method available within the camera, other than ISO to reduce the light, so it was necessary to use ND filters to get it down to a manageable level.

But this technique is not as necessary with the P4 Pro, as it has a variable aperture lens allowing you to reduce the light level on the sensor without needing ND filters.

Geebax Posted at 2017-4-28 19:10
I may be wrong here, but you appear to be relating the use of ND filters to still photos. While there are some situations where they might be beneficial to stills, the main reason for the use of ND filters on the Phantom aircraft is for video, specifically the earlier P3 and P4 aircraft that had fixed focus, fixed aperture lenses.

The idea is to introduce some blur to the frames by getting the shutter speed down to twice the frame rate. This has the effect of hiding the staccato effect of low frame rates by using the resultant blur to soften the transition from frame to frame. Shutter spee3d was the only method available within the camera, other than ISO to reduce the light, so it was necessary to use ND filters to get it down to a manageable level.

Geebax, you hit the nail right on the head. I only used stills to show that the camera would adjust exposure accordingly. the P4P is my first drone so I didn't experience the short-comings of previous models. I purchased the set of 3 ND+PL PolarPro filters which, in hindsight, was not necessary. The degree of polarizing is minimal and I'm now looking for just a PL filter that provides a higher degree of polarizing. Any suggestions?

Thanks!

Dennis D Posted at 2017-4-29 04:44
Geebax, you hit the nail right on the head. I only used stills to show that the camera would adjust exposure accordingly. the P4P is my first drone so I didn't experience the short-comings of previous models. I purchased the set of 3 ND+PL PolarPro filters which, in hindsight, was not necessary. The degree of polarizing is minimal and I'm now looking for just a PL filter that provides a higher degree of polarizing. Any suggestions?

Thanks!

Sorry, my aircraft is a P3 Pro, and I have the full set of filters, 8, 16 and 32. But they are quite small, and I have not seen a small enough PL or CPL to go on the front.

Here in Australia, the light is quite bright compared to northern latitudes, so the ND 16 is almost welded to the front of my camera.

Geebax Posted at 2017-4-29 15:27
Sorry, my aircraft is a P3 Pro, and I have the full set of filters, 8, 16 and 32. But they are quite small, and I have not seen a small enough PL or CPL to go on the front.

Here in Australia, the light is quite bright compared to northern latitudes, so the ND 16 is almost welded to the front of my camera.

yep Geebax same here. ND permanent fixture.

How are the ND filters for photography?
Do you use them, or take them off?

I understand they are filming, but don't you want the opposite effect, with fast shutter for photos?