ND Filters

[Koelkop]

Hello fellow pilots.

I need some advice on nd and polarizing filters.

I want to buy a set of filters. But I see that most sets have say a cp filter and the nd 4 to 16. Or you get kits with nd4 to 32 with no cp filter.

I live in South africa, most days very sunny. Do I need a nd32 to get the shutter speed down? How often are cp filters needed. I have no experience with filters so sorry if I ask silly questions

 

[bushie]

I live in Perth. Similar climate to you i imagine
I am fairly new to drones and video.

I initially bought a set of Neewer 4 8 and 16 nd and ND poloirid but found that not enough for our clear blue skies
Have just ordered a 32ND and will see how that goes

 

[msinger]

I live in South africa, most days very sunny. Do I need a nd32 to get the shutter speed down?

You might need an ND32 filter. If the filter set of your choice doesn't include it, you could buy an ND32 filter separately. You could also try what's in your kit and buy darker filters later if needed.

How often are cp filters needed.

Here are some good filter-related resources:

• Why use ND filters? (Frederick Hagan)
• Drone ND Neutral Density Filters || Why & When? (Drone Film Guide)
• How Polarizers and ND Filters work (Ian in London)
• How, When, and Why to Use a Polarizing Filter (Peter West Carey)

As for which filter brand to buy, there are several good brands to consider. You can find a list of commonly used filters here:

• Mavic Air ND Filters
• Mavic Pro ND Filters

 

[Koelkop]

Thanks guys. Think I will first buy a set of 4 to 32.

 

[Arley]

You might need an ND32 filter. If the filter set of your choice doesn't include it, you could buy an ND32 filter separately. You could also try what's in your kit and buy darker filters later if needed.


Here are some good filter-related resources:

• Why use ND filters? (Frederick Hagan)
• Drone ND Neutral Density Filters || Why & When? (Drone Film Guide)
• How Polarizers and ND Filters work (Ian in London)
• How, When, and Why to Use a Polarizing Filter (Peter West Carey)

As for which filter brand to buy, there are several good brands to consider. You can find a list of commonly used filters here:

• Mavic Air ND Filters
• Mavic Pro ND Filters

I too am considering a set of filters. I do not see the point of buying a CPL filter as this has to be adjusted 'on the go' & obviously this cannot be done with a drone. As for others, and using Amazon AU as my source, I always read the reviews. They vary so much that I'm not willing to splash out on gear that may cause gimbal problems, as said in some reviews.

 

[gnirtS]

I use a CPL as 95% of the stuff i do with the drone is still photos based and around water/jungle. I generally know what i want before i take off so set up the CPL, take what i need then return to land.
If i want to do video then i'll swap to a non polarised ND for a 2nd flight.
Most people with drones seem to fail to understand filters in general and CPLs even more so. They fail to realise they need exact, specific adjustment before each flight and only work at a very precise angle in flight even after that.

 

[reefranger]

I live in Perth. Similar climate to you i imagine
I am fairly new to drones and video.

I initially bought a set of Neewer 4 8 and 16 nd and ND poloirid but found that not enough for our clear blue skies
Have just ordered a 32ND and will see how that goes

Hey mate i use 32 nd polar pro takes out most of the sun glare

 

[gnirtS]

Hey mate i use 32 nd polar pro takes out most of the sun glare

..assuming you keep the subject and light source angle to within about 10 degrees and adjust it before flight for the same. Otherwise its not. Placebo effect.

 

[Storyline]

I bought a set of 4/8/16 NDPL from Polar Pro only to realise that I was getting blown out clouds on sunny days so I had to get a single 32NDPL.

Before I mount them I hold them up and look through them at an angle of 90° to the sun to find the active position and see what that is relative to the position of the writing around the filter. Then I mount them keeping the active position 'mark' at the top. Then for the flight, at least I know where to position the aircraft relative to the target to get the 'pop' from the filter. It is a compromise because it does not take into account any deviation from the horizontal ie looking down. It certainly makes you realise how easy it is to use a dSLR on a tripod !

I also plan to use them when flying from our boat. We keep her on the west coast of Scotland where the water is crystal clear so hope to get some shots looking down through the surface. Lots of trial and error there I guess

 

[gnirtS]

I bought a set of 4/8/16 NDPL from Polar Pro only to realise that I was getting blown out clouds on sunny days so I had to get a single 32NDPL.

Well an NDL isnt going to stop blown out highlights...

I also plan to use them when flying from our boat. We keep her on the west coast of Scotland where the water is crystal clear so hope to get some shots looking down through the surface. Lots of trial and error there I guess

90 degrees just won't work at all especially when dealing with reflected light (ie in particular water with various angles involve). The *only* way is look through it, rotate and fit at exactly the angle you saw visually reduced glare. It's not trial and error but you can only do it by eye looking through prior to the flight.

 

[Storyline]

Well an NDL isnt going to stop blown out highlights...



90 degrees just won't work at all especially when dealing with reflected light (ie in particular water with various angles involve). The *only* way is look through it, rotate and fit at exactly the angle you saw visually reduced glare. It's not trial and error but you can only do it by eye looking through prior to the flight.

I obviously did not explain myself clearly enough. The only reason for the 90° to the sun is that is the position where the polarising effect is at its strongest so it is easier to see the correct orientation which I find very difficult as the filter is so small. It also happens to be usually a good angle to photograph something relative to the sun with just about acceptable levels of glare and useful shadows to help with definition and structure.

Edit: I have not checked how it works yet but it may be that the Mavic 2 zoom lens will rotate when zooming which would make using a PL filter a lot easier (or useless, depending on what you want to do )

 

[gnirtS]

I obviously did not explain myself clearly enough. The only reason for the 90° to the sun is that is the position where the polarising effect is at its strongest so it is easier to see the correct orientation which I find very difficult as the filter is so small. It also happens to be usually a good angle to photograph something relative to the sun with just about acceptable levels of glare and useful shadows to help with definition and structure.

Except when dealing with reflections its 45 degrees and so on. The only way to line up a CPL is to look through it at the same angle, rotate then fit at the exact same angle.

Edit: I have not checked how it works yet but it may be that the Mavic 2 zoom lens will rotate when zooming which would make using a PL filter a lot easier (or useless, depending on what you want to do )

It would appear the outer part of that is just a cover, the rotation goes inside so it shouldn't mess it up. That said, they wont sell many zooms for people wanting an upgrade. Zoom is going to be for mainly new mavic owners. Other than zoom, its the same sensor and so on as used on the mavic 1....and the camera was its weakest part!

 

[Storyline]

Well an NDL isnt going to stop blown out highlights...



90 degrees just won't work at all especially when dealing with reflected light (ie in particular water with various angles involve). The *only* way is look through it, rotate and fit at exactly the angle you saw visually reduced glare. It's not trial and error but you can only do it by eye looking through prior to the flight.

Apols to the o/p for drifting from ND to NDPL
I have just spent some time reading a long technical article about how polarising filters work. Most of this I can understand including finally discovering what Kaesemann means that is printed on a nice Heliopan filter I have for my Lee filter system. Anyway, if I go slowly enough I can get my head around even the more technical bits but am still struggling with the absolute basics !

In particular, I want to know how best to get the most polarising effect when looking down on water. As far as I understand it, the (rotational) position of the filter on the lens is irrelevant if you keep the MP lens perpendicular (90°) to your target bit of water whilst at the same time keeping the sun also perpendicular to that same bit of water. The effect (irrespective of filter position) should be at its maximum. As you bring your drone round (still perpendicular to the water) to line up with the sun ie you, the water and the sun are all lined up then the effect is at its least.

So, the big question (for those with younger/better brains than me ) is, am I right ?!

 

[gnirtS]

Not quite in real world. The problem with looking down and water in particular are reflections. Although its "easy" to work out how to polarise a single direction light source that rapidly becomes a nightmare when its reflected off about 23 different waves and bounced back etc.

Also theres an important difference between linear and circular polarisers. Drones ones are circular and need to be adjusted.

Whilst what you say is true that polarisation effect is highest at 90 degrees to the light source and none directly into and away from the light source that assume the filter is adjusted correctly in the first place. By rotating you're actually changing the polarisation angles blocked so it needs to be correct to do anything at all regardless of angles.

Ultimately the way to use them in real life is set yourself up with the sun at the same angle you plan your shot, rotate it whilst looking through it, when you see the effect (glare goes, sky darkens or whatever), look at the markers on the side and fit it to the drone at that exact angle.
Then provided you maintain that angle on the drone you'll have polarisation (provided you arent directly into or away from the light source as said above).

Obviously, rotate the drone, find a new subject and so on and that effect is going to be minimal or zero.

You see lots of people saying "i took this awesome sunset shot with a PL" whilst looking straight into the sun. Those people havent understood it and the PL had no effect.

From that CPLs are only really useful if you know in advance what shot you want and set it up before hand so obviously more useful for stills. I do use it a bit for video as i do a lot of coral reef video so want to remove glare. But the setup is the same and i know once i change angles ive lost the effect.

Where you really DONT want one is a panorama or 360. As those cover a range of angles from the light source you get light/dark patches in sky where there is and isn't polarising effect and it looks quite ugly so take it off if you're planning on those on a flight.
For example a 180 degree panorama is going to go all angles from directly into, 90 degrees from and directly away from a light source so there'll be areas of no and areas of maximum polarisation.


https://hoyafilterusa.com/how-circular-polarizer-filters-work/ isnt particularly well written but gives an idea.

 

[Top Hat]

When using ND filters, do you unscrew the MP lens cover or you install the filter on top of it?
Sorry,not really a photo/video enthusiast, I just fly most of the time and shoot vids/pics sometimes.
My main use of drone w/ cam is to see where I'm flying around but now getting intrigue w/ filters.

 

[Appalachian Aerials]

Just be warned: the motion blur the filters will cause will ruin still images. Can't fly with them if you're going to take pictures of people/animals.

 

[Storyline]

When using ND filters, do you unscrew the MP lens cover or you install the filter on top of it?
Sorry,not really a photo/video enthusiast, I just fly most of the time and shoot vids/pics sometimes.
My main use of drone w/ cam is to see where I'm flying around but now getting intrigue w/ filters.

I was not even aware you could unscrew the lens cover on the MP but the filters I use (Polar Pro) are just a push fit over the complete lens assembly. The instructions make them sound quite difficult to fit but in reality they go on and come off very easily. If you use the commonly recommended shutter speeds and frame rates I find that I almost always have to use one.

 

[yetimeistar]

Hi everyone!

Just recently purchased my first drone second hand! Having a blast learning it's capabilities. I have a Mavic Air.

I like to make videos in general and that is what my drone will be used mainly for (there will be the occasional sports mode fun). I've been trying to get some idea on the use of the ND filters. I know that depending on the direction the shot will be set up will determine the settings overall. Eg shooting away from the sun vs going into the sun. Does this mean when you set up your shot with a ND filter you should generally stick to facing that direction? Or do ppl just fly around freestyle and just shoot whatever. I imagine it is the latter, but I haven't been able to find other ppl experience.