ND Filter for a beginner

[Harlov]

Hello

Completely new to this with ND Filter

I have the following DJI ND Filter ND 16, 64, 256 and would like help with how to set the camera settings in the best way, have googled this but will not be really wise anyway. Is there any recommendation on camera settings that I can start from

/ Peter

 

[slup]

The first thing you need to ask yourself is why you want to use a ND filter, this as a ND isn't an absolute necessity.

A ND only do one thing ... it let in less light to the sensor & by that make the shutter slower. This can be used if you have a need for motion blur when filming, or for stills if you want to add a certain artistic smoothness of for instance flowing water in the pic.

The dominating use of a ND when it comes to drones is when you film ... the motion blur that's created by that slower shutter will make the film more pleasing to the eye, it will feel less "sticky" as no frame are pin sharp all the time. This will also help out with the risk of a jittery look if it's a lot of motion in the film, like when you pan the drone, tilt the camera or flying really close to objects.

The guideline regarding a natural motion blur (the "180 degree rule") is a shutter speed of 2 x the used frame rate ... meaning, if you use 25fps you should use a shutter on 1/50sec.

So ... when filming in ordinary daylight you easily will end up with shutter speeds on like 1/1000sec without a ND & with the ISO setting on the lowest (100). So you can't just switch to manual exposure settings & dial in a shutter of 1/50sec as that will severely overexpose the film ... you need to shield out some light, & it's there the ND comes into play, you find the ND strength that allows you to have 1/50sec while at the same time get a properly exposed film.

But bear in mind ... if a ND should be of any valuable use you need to have motion in the film, otherwise a ND only adds a problem ... making it extra fiddly to film.

Photo drones usually doesn't fly that fast, & usually rather far away from objects & ground ... so all motion in the film will be rather slow & the use of a ND to keep the "180 degree rule" isn't important anymore. As a guideline ... if longer than 30m from objects or ground, motion blur doesn't have to be considered any more ... that is if you doesn't wildly pan back & forth in high speed, but that will be ugly no matter if you use a ND or not.

Here below a simple chart about when to use different ND strengths to get in the correct ball park of the correct shutter speed.

 

[Harlov]

Thanks for your info on ND filters it was an interesting read. In any case, I plan to try with the ND filters that I have that came with the drone mostly to learn, but as you say, I have come to the conclusion that the right setting for the camera is best without ND.

My settings are for 4K
30 Fps (60Fps?)
shutter 1/60 (where can I adjust a little if needed?)
Iso 100

 

[GadgetGuy]

Thanks for your info on ND filters it was an interesting read. In any case, I plan to try with the ND filters that I have that came with the drone mostly to learn, but as you say, I have come to the conclusion that the right setting for the camera is best without ND.

My settings are for 4K
30 Fps (60Fps?)
shutter 1/60 (where can I adjust a little if needed?)
Iso 100

You'll want that extra shutter stop at dusk by switching to 1/30 sec

 

[slup]

...I plan to try with the ND filters that I have that came with the drone...

The only filter there that will be to any use for filming this time of the year in Sweden is the ND16. It will require a ambient light coming from a clear sunny sky closer to mid-day ... if duller light, the film will be somewhat underexposed as the ND16 shields out to much light ... maybe you in that case need to rise the ISO setting a bit.

The ND256 perhaps can be used in lower ambient light if you want to test to take still pictures ... ie. get smooth flowing water or red stripes from the rear lights from cars on a road or similar. During daylight conditions an ND up on 1000 or even higher is required in order to slow the shutter enough for purposes like this.

My settings are for 4K
30 Fps (60Fps?)
shutter 1/60 (where can I adjust a little if needed?)
Iso 100

With a shutter on 1/60sec in daylight conditions a ND is definitely needed ... without it, the film will be totally overexposed. With a blue & sunny sky I think ND16 will work.

Regarding adjustments ... when working with ND's you can go in 2 directions.

One direction where you continue to use a auto shutter (but lock the ISO setting on the lowest if possible). When using a ND the auto shutter will be slowed down to around values according to the "180 degree rule" in the brightest conditions, but in shadows the auto shutter will adjust to even slower values (which adds further motion blur just there...) So this method will not be the purists way of working ... but it will be somewhat ok.

The other way is that you go for full manual settings all over ... you set the ISO & dial in a shutter on exactly what you want. This means that the exposure will not change depending on if you film in changing conditions or not & that the amount of motion blur will be the same all the time.

I believe that you switch between auto/manual settings on the bottom right icon in the DJI Fly app ... then click on the shutter and/or ISO to make adjustments.

 

[Harlov]

The only filter there that will be to any use for filming this time of the year in Sweden is the ND16. It will require a ambient light coming from a clear sunny sky closer to mid-day ... if duller light, the film will be somewhat underexposed as the ND16 shields out to much light ... maybe you in that case need to rise the ISO setting a bit.

Thanks for the tips, will try me out with different settings for the camera