Why, oh, Why an ND filter?

[Shaun Roster]

I'm a Pro Photographer too, but get a lot of aerial video requests for clients too. The primary reason you see lots of people discussing ND filters is simply due to the fact they want to achieve cinematic smooth video by using the 2:1 ratio rule. Shutter speed is 2 times Frame Rate, most folk record cinematic at 30fps so they look for a 1/60th shutter speed. 60fps = 1/120th shutter speed. I have an 4 set ND filters (ND4,8,16,32) and choose which one to put on based on the average light of the day such that, by keeping ISO 100 and a reasonable FStop it gives me my 1/60th shutter speed. I also capture still imagery at the same time, with the ND filter on, which unless you're shooting stills whilst fast manoeuvring, keeps everything looking sharp, but you can always take down your FStop or up the ISO a little if you want to bring the shutter speed up for a few still shots. Hope that helps a little. If i'm flying for stills photography only hen I don't use an ND filter, unless i'm looking for special smoothing effects of course.

 

[GadgetGuy]

My two cents.. I use a ND filter so my videos aren't over exposed. Both video and pictures turn out great with the filter! I would not fly without one.

The intended use of ND filters has nothing to do with controlling exposure. Their sole purpose is to control shutterspeed. If you are using them to prevent over exposure, you completely misunderstand their use.

 

[Shaun Roster]

The intended use of ND filters has nothing to do with controlling exposure. Their sole purpose is to control shutterspeed. If you are using them to prevent over exposure, you completely misunderstand their use.

Although correct in principle there are likely OPs who set a shutter speed for cinematic which results in perceived ‘over exposure’ hence they use an ND in their minds to correct for over exposure. Just a different way to look at it I guess!!

 

[GadgetGuy]

Although correct in principle there are likely OPs who set a shutter speed for cinematic which results in perceived ‘over exposure’ hence they use an ND in their minds to correct for over exposure. Just a different way to look at it I guess!!

Good point! Thank you for offering that perspective.

 

[WV. Rootman]

Nd filters also very useful when video waterfalls. I’ve done a few videos of falls and wanted a slower shutter.

 

[GadgetGuy]

Nd filters also very useful when video waterfalls. I’ve done a few videos of falls and wanted a slower shutter.

Indeed. That's the primary purpose of ND's, which is to control and lower shutter speed under bright light to create motion blur, whether for video or stills. In some still applications, this can also even enable using the camera flash sync speed for more flash power, if desired.

 

[JeffreyS]

My two cents.. I use a ND filter so my videos aren't over exposed. Both video and pictures turn out great with the filter! I would not fly without one.

That's not what ND's are for. If your overexposing, simply dial back your exposure comp.

 

[GadgetGuy]

That's not what ND's are for. If your overexposing, simply dial back your exposure comp.

Indeed. The filter manufacturers have created a gross misunderstanding, implying that filters are an absolute necessity for every drone owner. They are not! 99% of the filter purchasers do not need ND filters, nor understand their real purpose, and they do not understand how to use the filters they buy for their intended purpose. Unless you shoot video, you have absolutely no need for any ND filters, except to create deliberate motion blur in photographs, which is the opposite of what most desire. Most photographers want a sharp photograph. Lowering shutter speeds with ND filters only introduces motion blur.

 

[With The Birds]

I wish it was possible to change a filter and rotate a polarizer while the AC was up.

I usually test at which angle and direction (usually 90° from the sun) the polarizer yields the best effect and try to screw it like that to the AC. Or point the AC camera to that direction up in the blue sky and rotate the polarizer while trying to decide the best angle on the tablet's screen.

I usually add a ND or polarizer for video and thus make a compromise for image sharpness.

BTW an old rule for hand-held photography was to use a shutter speed no longer than the inverse of the focal length (50mm lens can usually be held steady for 1/50 s shots, for example). If that roughly applies also for the P3P, then the shutter speed could go as long as 1/20 s (focal length 3.61mm or 20mm @ 35mm format equivalent), right?

p.s. great photos!

There is a new rule for phantom drones with image stabilisation that tells us you can go out to two seconds exposure fairly consistently in still conditions hovering.