To ND or to not ND?

[landmark orbiter]

I have been reading about ND filters a lot, but still did not grasp the practical use of it.
In other words: what are the best settings of the camera and which ND filter to make the video looking better?
The more YT videos I look at, the more confused it gets. One says this, and the other says the opposite...

@SmilingOgre: "When possible, I like to match the shutter angle of 180° as well." what do you mean by that? How can one change the shutter angle?

The practical use is NDs:

- Keep motion blur looking as natural as possible with the right amount of ND. As an example I wanted to take a picture of my drone hovering with a bit of a blurred background with my DSLR. Without an ND, the propellers would not look right at all, so I would need to use the right NDs to be able to use a shutter speed of 1/50th and an F2.8 aperture with minimum ISO.
- Lens have an optimum aperture, and generally speaking, you don't want to be using the aperture at F22 or similar in bright sunlight.

To get natural-looking motion blur, you need your shutter to be 1/50th if in the UK. This mirrors how our eyes see the world. However, as it has already been said in this thread, if you are just shooting scenery and everything is generally wide, you don't need to worry about this. But if you had a Mavic and it's 7x telephoto and you're following anything moving like a bike, a car, even a stream, then ideally you want some motion blur in that.

 

[SmilingOgre]

I have been reading about ND filters a lot, but still did not grasp the practical use of it.
In other words: what are the best settings of the camera and which ND filter to make the video looking better?
The more YT videos I look at, the more confused it gets. One says this, and the other says the opposite...

@SmilingOgre: "When possible, I like to match the shutter angle of 180° as well." what do you mean by that? How can one change the shutter angle?

I had no idea it was "relic", lol. In the world of cinematography they look at the opening and closing of a shutter as a 360° motion. 180° would be having the shutter open for half of the frame. Another way to state that would be shutter speed double the frame rate. If I set my cinema camera at 180° then no matter what frame rate I choose the shutter will always only be open half of the frame. A 90° shutter angle would have the shutter open 1/4 of the frame and so on.

 

[marcosvc]

Reasons why the ND filter is necessary, or useful

For pictures. Movement effect. Longer exposure time. After setting the ISO to minimum, the diaphragm closed and the exposure was not long enough. In other words, if you want longer exposure times, whatever your reason, the ND filter is useful for that.
For pictures. Use a larger opening aperture than you can achieve. If the environment is too bright, at the smallest aperture you may not get the effect of a blurred image background. With the ND filter you block excess light and achieve the effect.
For Video. You cannot reduce the exposure to achieve the 180 degree shutter rule (shutter speed half the frame rate) to keep the video fluid. Need ND filter

Summary

• Picture - longer exposure time
• Picture - aperture more open than it is achieving
• Video - Use the shutter speed half the frame rate

 

[NightFlightAlright]

Just wondering what are the reasons for needing ND filters on drones for video?
Unless you’re recording something that needs motion blur?

Because you always need mo-blur.

Unless you want that “Saving Private Ryan” stroboscopic look from a very fast shutter.

Motion blur is critical part of how the human vision system detects motion, and is therefore ultra critical for film/video which is just a series of still images flashed at a fast enough rate to “begin to” integrate into fluid motion—so long as there is motion blur.

It is particularly important at the cinema rate of 24FPS. But still needed at 30fps.

At very high frame rates (greater than 72fps) it becomes less needed or not needed. But no one is projecting faster than 60fps.

At 60fps, slower moving objects may not need mo-blur, but faster objects still do to help demonstrate speed.

Therefore, ND filters are nearly mandatory for day work. I happen to like the K&F variable, which is adjustable for 1 to 5 stops.

 

[jephoto]

Your ND4 filter doesn't "change the sun's rays a little bit".
It uniformly reduces the light level across the frame by 75%.
The only thing it changes is the light level, which forces a slower shutter speed.

Yep. Many people don’t understand what an “N.D.“ filter is.
They’re not thinking about the actual name which is neutral density filter
NEUTRAL, as in it doesn’t change anything in the way of your contrast or color or the suns rays or anything.
And DENSITY as in it just makes it darker. That’s all it does. Allows you to use a slower shutter speed- or wide open aperture if you camera/lens has that capability.

It’s just gray glass.

 

[jephoto]

Because you always need mo-blur.

Unless you want that “Saving Private Ryan” stroboscopic look from a very fast shutter.

Motion blur is critical part of how the human vision system detects motion, and is therefore ultra critical for film/video which is just a series of still images flashed at a fast enough rate to “begin to” integrate into fluid motion—so long as there is motion blur.

It is particularly important at the cinema rate of 24FPS. But still needed at 30fps.

At very high frame rates (greater than 72fps) it becomes less needed or not needed. But no one is projecting faster than 60fps.

At 60fps, slower moving objects may not need mo-blur, but faster objects still do to help demonstrate speed.

Therefore, ND filters are nearly mandatory for day work. I happen to like the K&H variable, which is adjustable for 1 to 5 stops.

Do you mean this?
K&F Concept 2-Pack VND/CPL Filter Kit for DJI Mavic 3/Mavic 3 Cine, 28 Multi-Layer Coatings Variable ND2-ND32 (1-5 Stops) & Circular Polarizer Filter Set
Amazon.com

 

[jephoto]

Since I got the M3 I got kind of lazy and wasn't bothering with the NDs or trying to get my shutter speed down. But yesterday I had to shoot a few more clips at a job I'd done last Friday and put the ND16 on (DJI's filter set). The light was similar to Friday - perfect for video as it was wispy clouds and sort of hazy sun. Some blue sky but the contrast in shadows was real soft.
Anyway I was shooting 30FPS, so got my shutter to 1/60th anywhe3re from ƒ4.0 - ƒ7.1 a couple times.. Mostly ƒ 4.5-5.6 and have to say, it does look way smoother. Anytime cars went down the street or people walked by it was noticeably smoother.
I'll make more effort to do that in the future when doing a lot of video.

 

[dajomu]

For 60 years I've been using at least the lowest ND or other filters on all my equipment just to protect the camera lens. The change in DOF or shutter speed was of no consequence to me

Using an ND filter just for lens protection is a dubious practice, even if you've been doing it for 60 years. Just sayin'. (70 year old commercial photographer here).

 

[NightFlightAlright]

Do you mean this?
K&F Concept 2-Pack VND/CPL Filter Kit for DJI Mavic 3/Mavic 3 Cine, 28 Multi-Layer Coatings Variable ND2-ND32 (1-5 Stops) & Circular Polarizer Filter Set
Amazon.com

Yes, except for the mini 3 pro… and yea K&F … I keep getting confused for K&H, which makes drafting equipment (like old school pen/ink LOL… obvious senior moment)…

 

[NightFlightAlright]

Since I got the M3 I got kind of lazy and wasn't bothering with the NDs or trying to get my shutter speed down. But yesterday I had to shoot a few more clips at a job I'd done last Friday and put the ND16 on (DJI's filter set). The light was similar to Friday - perfect for video as it was wispy clouds and sort of hazy sun. Some blue sky but the contrast in shadows was real soft.
Anyway I was shooting 30FPS, so got my shutter to 1/60th anywhe3re from ƒ4.0 - ƒ7.1 a couple times.. Mostly ƒ 4.5-5.6 and have to say, it does look way smoother. Anytime cars went down the street or people walked by it was noticeably smoother.
I'll make more effort to do that in the future when doing a lot of video.

This…

For the “feature film look” set to 24FPS and 1/48 (1/50) shutter… mo-blur is slightly enhanced using 1/40, but opening it up more than that has an unusual effect that makes it look “even more video-ish”… the sweet spot is 24 at 1/50.

 

[jephoto]

Thx. For the jobs I’m doing- school websites it doesn’t need to be cinematic, just look good.
The guy doing the editing (I’m still not doing much video edits) he just wants 1080p and 30fps.
They get LOTS of content from photogs all over the country. I’ll bet all that adds up to a bunch of terabytes a year. And slowing down the edits if we give him 4k.
This won’t be seen at a theater near you soon…

 

[Ronny St.]

Thanks everyone for explaining the need and use of ND filters, I learned a lot in this topic!

 

[Ronny St.]

I had no idea it was "relic", lol. In the world of cinematography they look at the opening and closing of a shutter as a 360° motion. 180° would be having the shutter open for half of the frame. Another way to state that would be shutter speed double the frame rate. If I set my cinema camera at 180° then no matter what frame rate I choose the shutter will always only be open half of the frame. A 90° shutter angle would have the shutter open 1/4 of the frame and so on.

Thank you, SmilingOgre, that is great (new) info for me, and very clearly explained

Btw: Does anyone know this set also exists for M2P? Seems very handy not having to carry a lot of filters with you.
K&F Concept 2-Pack VND/CPL Filter Kit for DJI Mavic 3/Mavic 3 Cine, 28 Multi-Layer Coatings Variable ND2-ND32 (1-5 Stops) & Circular Polarizer Filter Set

 

[NightFlightAlright]

Thx. For the jobs I’m doing- school websites it doesn’t need to be cinematic, just look good.
The guy doing the editing (I’m still not doing much video edits) he just wants 1080p and 30fps.
They get LOTS of content from photogs all over the country. I’ll bet all that adds up to a bunch of terabytes a year. And slowing down the edits if we give him 4k.
This won’t be seen at a theater near you soon…

Yes certainly if you need to match other materials or otherwise are specified at 30… just saying since we’re on the subject, that “cinema” feel starts with 24fps and 1/50…

 

[NightFlightAlright]

Thank you, SmilingOgre, that is great (new) info for me, and very clearly explained

Btw: Does anyone know this set also exists for M2P? Seems very handy not having to carry a lot of filters with you.
K&F Concept 2-Pack VND/CPL Filter Kit for DJI Mavic 3/Mavic 3 Cine, 28 Multi-Layer Coatings Variable ND2-ND32 (1-5 Stops) & Circular Polarizer Filter Set

I have the K&F for my mini3p, I have another brand for my mini2, and I never found a variable ND that fit the mini 2, though it would be possible as I have rotatable polarizers for the mini 2.

The variable ND is just two polarizers back to back, with one of them able to rotate. When you rotate one polarized filter against another polarized filter, you adjust the total light transmission.

 

[landmark orbiter]

You’re welcome