DJI ND filters or is there a better one?

[CanadaDrone]

Awesome...thank you I'll check out the brands you mentioned and see what I can find.
Do you happen to have an opinion about "fixed" vs "variable" ND filters? I like the idea of having just Variable ND filters rather than a whole slew of "fixed" ND filters. Do you feel like ND filters are needed to get smooth cinematic footage in bright sunny conditions. I still need to do my own research but thought I would ask different people's opinnions on the topic.

If you are at all serious about shooting video, you really do need a set of ND filters, especially on a drone like the Air 2S which does not have a variable aperture. You always want to shoot at the lowest ISO possible for maximum image quality, and since the aperture is not variable, that leaves ND filters as pretty well your only option to control wider swings in exposure (you still need ND filters on variable aperture drones like the M2P, just not as many). Getting good quality footage is pretty much impossible without ND filters.

As you may have already read, the general rule of thumb is to keep your shutter speed around double the frame rate, so for example if you were shooting 4K/30p you would want a 1/60 shutter speed. The idea is that ratio gives you the most realistic/cinematic footage similar to what humans see with the naked eye, particularly in terms of motion blur. That is simply a guideline and there is some wiggle room there - for example if I am going to be flying really close to something and at speed, I raise the shutter speed a bit as it can start to get a bit too blurry for my liking. Use that rule as a guide and feel free to play around with it. When your shutter speed gets too high, the footage will look like it's stuttering and will generally just look very unnatural (especially noticeable with something like ocean waves). If the shutter speed is too low, everything will be blurry, and that will be exaggerated the faster you fly and/or the closer you fly to something.

Regarding variable NDs, there is nothing wrong with them (as long as they do not rotate at all by themselves during flight), but they are somewhat pointless because you still have to land the drone to adjust it. I guess it saves you from having to remove/replace a filter, but chances are you aren't going to need to adjust the ND filter for any given ~25 minute flight anyway. Also, variable ND filters have a second piece of glass in them, and any time you introduce extra layers of glass, you technically reduce image quality and increase chance of flare/reflections. It's unlikely you would notice any quality difference in real world shooting though. Just make sure you are not buying a graduated ND filter, which are just as much of a nightmare to use on drones as polarizing filters unless used for a very specific purpose.

You really only need 4 filters for 99% of scenarios (ND 4, 8, 16, 32). If you are going to fly over white sand or snow in bright sunlight, you may need ND64. If you wanted to do some low-shutter-speed photography, for example to blur the movement of a waterfall, you may also need a ND64 or higher.

PolarPro makes a VND covering ND4-32 and that would be all you needed for most scenarios if you wanted to go that route. A ND4 cuts 2 stops of light (25% transmission), and it is halved thereafter every time the ND number doubles - so a ND8 cuts 3 stops (12.5% transmission), ND16 cuts 4 stops of light (6.25% transmission), etc. When I had a drone limited to F2.8, by far my most used ND's were 8 and 16.

 

[pommy]

@JetM I can guarantee the Air 2S doesn’t have a clear lens with it. The bezel is there to cover the mounting points and aesthetics only.

You won’t find a clear lens without a coating from a reputable manufacturer. Nobody would sell a piece of glass without a protective coating on it of some sort.

I own the one below and have no issues at all, but obviously research them (as I did) and make an informed decision

Air 2S Professional Clear UV

 

[JetM]

If you are at all serious about shooting video, you really do need a set of ND filters, especially on a drone like the Air 2S which does not have a variable aperture. You always want to shoot at the lowest ISO possible for maximum image quality, and since the aperture is not variable, that leaves ND filters as pretty well your only option to control wider swings in exposure (you still need ND filters on variable aperture drones like the M2P, just not as many). Getting good quality footage is pretty much impossible without ND filters.

As you may have already read, the general rule of thumb is to keep your shutter speed around double the frame rate, so for example if you were shooting 4K/30p you would want a 1/60 shutter speed. The idea is that ratio gives you the most realistic/cinematic footage similar to what humans see with the naked eye, particularly in terms of motion blur. That is simply a guideline and there is some wiggle room there - for example if I am going to be flying really close to something and at speed, I raise the shutter speed a bit as it can start to get a bit too blurry for my liking. Use that rule as a guide and feel free to play around with it. When your shutter speed gets too high, the footage will look like it's stuttering and will generally just look very unnatural (especially noticeable with something like ocean waves). If the shutter speed is too low, everything will be blurry, and that will be exaggerated the faster you fly and/or the closer you fly to something.

Regarding variable NDs, there is nothing wrong with them (as long as they do not rotate at all by themselves during flight), but they are somewhat pointless because you still have to land the drone to adjust it. I guess it saves you from having to remove/replace a filter, but chances are you aren't going to need to adjust the ND filter for any given ~25 minute flight anyway. Also, variable ND filters have a second piece of glass in them, and any time you introduce extra layers of glass, you technically reduce image quality and increase chance of flare/reflections. It's unlikely you would notice any quality difference in real world shooting though. Just make sure you are not buying a graduated ND filter, which are just as much of a nightmare to use on drones as polarizing filters unless used for a very specific purpose.

You really only need 4 filters for 99% of scenarios (ND 4, 8, 16, 32). If you are going to fly over white sand or snow in bright sunlight, you may need ND64. If you wanted to do some low-shutter-speed photography, for example to blur the movement of a waterfall, you may also need a ND64 or higher.

PolarPro makes a VND covering ND4-32 and that would be all you needed for most scenarios if you wanted to go that route. A ND4 cuts 2 stops of light (25% transmission), and it is halved thereafter every time the ND number doubles - so a ND8 cuts 3 stops (12.5% transmission), ND16 cuts 4 stops of light (6.25% transmission), etc.

Thanks for sharing that info and recommendations. Fantastic information!!! And super helpful. FYI, I live in Sunny San Diego so I'm typically flying in very sunny bright conditions and sometimes over the ocean. But those conditions can change quickly if the fog comes in. I was leaning towards getting variable ND filters just to eliminate the hassle and "wear and tear" (to the Gimbal/camera) of putting on and taking off different ND filters. I've heard that removing them can be a bit of a task and may put pressure on the gimbal/camera. I do realize that I'd have to adjust the variable ND filters as conditions change but having them would save me some time having to change the filter. You make a good point about the extra glass in the vND filters.
Given that I tend to fly over the Ocean quite a bit would you recommend buying a separate set of polarized filter for those situations. If I'm not mistaken it seems like you can get them as nVD filters as well. Some seem to be described as "circular"..not sure what that means. Maybe means the are variable?

 

[JetM]

@JetM I can guarantee the Air 2S doesn’t have a clear lens with it. The bezel is there to cover the mounting points and aesthetics only.

You won’t find a clear lens without a coating from a reputable manufacturer. Nobody would sell a piece of glass without a protective coating on it of some sort.

I own the one below and have no issues at all, but obviously research them (as I did) and make an informed decision

Air 2S Professional Clear UV

Thanks. I believe you. Interesting that the MP2 has one but the Air2S doesn't...maybe a cost cutting move by DJI. What brand did you end up purchasing?

 

[CanadaDrone]

Thanks for sharing that info and recommendations. Fantastic information!!! And super helpful. FYI, I live in Sunny San Diego so I'm typically flying in very sunny bright conditions and sometimes over the ocean. But those conditions can change quickly if the fog comes in. I was leaning towards getting variable ND filters just to eliminate the hassle and "wear and tear" (to the Gimbal/camera) of putting on and taking off different ND filters. I've heard that removing them can be a bit of a task and may put pressure on the gimbal/camera. I do realize that I'd have to adjust the variable ND filters as conditions change but having them would save me some time having to change the filter. You make a good point about the extra glass in the vND filters.
Given that I tend to fly over the Ocean quite a bit would you recommend buying a separate set of polarized filter for those situations. If I'm not mistaken it seems like you can get them as nVD filters as well. Some seem to be described as "circular"..not sure what that means. Maybe means the are variable?

You're welcome.

If you're flying over the ocean with sun reflecting off, you may find use for a ND64. It's hard to say for sure. Most kits cover ND4-32, and then you could buy a ND64 separately if you wanted. I find most of the 'complete' bundles to be a bit too extreme, and you end up paying for filters up to ND256 which you will probably never use.

Fair point about wear & tear, and sometimes the filters can be a bit tricky to remove. PolarPro includes a handy little tool for this to make it easier, I am not aware of anyone else that includes that tool. Certainly you want to be holding the gimbal nice and secure before you torque it for filter install or removal. I think you will be just fine with a variable ND, and as I mentioned earlier I think the ND4-32 will probably have you covered for most scenarios. ND4 is usually for dawn/dusk, ND8 overcast/evening, ND16/32 for sunny conditions, just as a very rough guide.

Polarization is one effect that no post-processing software can reproduce, not even close in fact, so if you want that look the only way to get it is to use a physical polarizer. Polarizers can both enhance or remove reflections, so depending on the scenario you might want one or the other. For example if you were shooting a landscape with lots of foliage, you may want to take the reflections off the leaves - or the most common example, making water less reflective and more see-through. Sometimes though you want the reflection enhanced - for example a rainbow or if there is a nice sunset reflecting off some calm water - polarizers can do that too.

Now, the hard part - If the filter is going on a drone, there is little value in an adjustable/rotating one because chances are you want maximum polarization if you are bothering to use a polarizing filter in the first place. Basically rotating it toggles the angle relative to the sun that receives maximum polarization, but it cannot magically produce a polarized effect at any angle - think of it more as changing the strength of polarization at any given orientation to the sun. It would also allow you to reduce the amount of polarization while flying in the direction of maximum polarization (90 degrees to the sun), but that would be something you would have to set on the ground anyway and there are far fewer scenarios where you only want a partial polarization. Whether you have a filter capable of rotating or not, you are bound to a single direction of flight if you don't want your footage to change mid-flight. At 180 degrees and 0 degrees to the sun there is no polarization. Maximum polarization is always at 90 degrees to the sun. If the sun is directly above you at high noon in an area near equator, you can get pretty broad polarization because most horizontal orientations will be roughly 90 degrees to the sun. If the sun is lower in the sky, there is a much tighter and less useful range that you will be able to achieve good polarization (basically straight up or straight down).

So let's say you were in Hawaii and wanted to get a nice shot over a coal reef, a polarizer would potentially be great for that, but you would just have to carefully plan the flight. If you wanted to fly in a different direction, you would need to bring the drone back home to adjust or remove the polarizer to avoid uneven footage.

It's a good tool to have in the tool box, it just requires careful planning to get the most out of it and it's not something you want to just leave on and forget about like you can do with a standard ND filter. Most filter companies do a very poor job of explaining this to people and simply choose to market their PL filters as "vivid" or whatever, giving the customer the impression that they can just use them for any scenario and get better colors, which is far too simple and not the case.

RE: Linear vs Circular polarizers - A linear polarizer will only let light through that is polarized in the same direction as the filter is currently turned. Modern autofocus systems have problems with this, so you will basically never see anything other than a circular polarizer and there is no reason to ever use a liner polarizer in the context of taking photos/video. Circular polarizers have a layer behind the linear polarizing layer that "re-polarizes" the light in a different way so that the autofocus can function as intended.

Any polarizer you buy will likely have a rotating ring on the front, allowing you to adjust the strength of polarization, but that is totally useless when the drone is 400ft in the air haha. If you are using a polarizer on a DSLR or something, you simply reach forward and make the necessary adjustments, no big deal.

Also note that polarizers cut about a stop of light, so they are equivalent to a ND2, roughly speaking. Since you never would want to leave a polarizer on your lens all the time, you do not want to buy ND/PL combination filters *unless* you also have a non-polarized version of that same ND filter to use as well. If you want a polarizer, it does make sense to get a ND/PL combo if you are in a really bright area and have a fixed aperture drone, but just be aware that you will not want to use this filter very often due to the limitations above. Most of the time you will probably want to fly with regular ND's which have no such orientation limitations, and I think you will find that from high up in the air, polarizing is not as obvious as it is on the ground, but it is certainly still noticeable and YMMV there depending on conditions.

One final thing to note, is that using polarizers on very wide lenses (like 24mm on the Air2S) you can sometimes get an uneven ploarizing effect. This is typically most noticeable with blue skies, where the middle will be much darker than the edges. Polarizers just work better on longer focal length lenses, but most people want them for landscapes, which are typically done on wide angle lenses, so it's a bit of a compromise.

Sorry that was long and I rambled a bit, if you need clarity on anything just ask.

 

[blubyyou]

So I have a few questions about filters for the DJI Air 2S. I got the normal package but do intend to buy a couple of extra batteries (that's all from the fly more package I really feel that I need). However, I'd like to have some filters on hand just in case I need them. So my question is: should I go with DJI's filters and buy one from someone who actually did get the Fly-More-Combo but don't want the filters or should I go with some other vendor like Freewell or PolarPro? Also, what range of filters would it be best to have. I think the DJI filters go from ND 4 to ND 32 so would I need a 64 filter too? Sorry if this has already been discussed. I haven't seen any threads on it so far. Thanks!

I fly with a Moment VND filter on my A2. About $30. I’m quite pleased. Haven’t taken it off since I bought it 3 months ago.

 

[Dan AISCF]

Even with filming straight on or any still photo the polarizer cannot cover the 22mm eqivalent angle of view on the 2S.So if your shooting a blue sky background about half of it will be polarized and the rest after a taper off will not.

This is great to know, I didn't know that. Thanks. Just another reason for me not to use CPL's at all on my 2S.

 

[JetM]

You're welcome.

If you're flying over the ocean with sun reflecting off, you may find use for a ND64. It's hard to say for sure. Most kits cover ND4-32, and then you could buy a ND64 separately if you wanted. I find most of the 'complete' bundles to be a bit too extreme, and you end up paying for filters up to ND256 which you will probably never use.

Fair point about wear & tear, and sometimes the filters can be a bit tricky to remove. PolarPro includes a handy little tool for this to make it easier, I am not aware of anyone else that includes that tool. Certainly you want to be holding the gimbal nice and secure before you torque it for filter install or removal. I think you will be just fine with a variable ND, and as I mentioned earlier I think the ND4-32 will probably have you covered for most scenarios. ND4 is usually for dawn/dusk, ND8 overcast/evening, ND16/32 for sunny conditions, just as a very rough guide.

Polarization is one effect that no post-processing software can reproduce, not even close in fact, so if you want that look the only way to get it is to use a physical polarizer. Polarizers can both enhance or remove reflections, so depending on the scenario you might want one or the other. For example if you were shooting a landscape with lots of foliage, you may want to take the reflections off the leaves - or the most common example, making water less reflective and more see-through. Sometimes though you want the reflection enhanced - for example a rainbow or if there is a nice sunset reflecting off some calm water - polarizers can do that too.

Now, the hard part - If the filter is going on a drone, there is little value in an adjustable/rotating one because chances are you want maximum polarization if you are bothering to use a polarizing filter in the first place. Basically rotating it toggles the angle relative to the sun that receives maximum polarization, but it cannot magically produce a polarized effect at any angle - think of it more as changing the strength of polarization at any given orientation to the sun. It would also allow you to reduce the amount of polarization while flying in the direction of maximum polarization (90 degrees to the sun), but that would be something you would have to set on the ground anyway and there are far fewer scenarios where you only want a partial polarization. Whether you have a filter capable of rotating or not, you are bound to a single direction of flight if you don't want your footage to change mid-flight. At 180 degrees and 0 degrees to the sun there is no polarization. Maximum polarization is always at 90 degrees to the sun. If the sun is directly above you at high noon in an area near equator, you can get pretty broad polarization because most horizontal orientations will be roughly 90 degrees to the sun. If the sun is lower in the sky, there is a much tighter and less useful range that you will be able to achieve good polarization (basically straight up or straight down).

So let's say you were in Hawaii and wanted to get a nice shot over a coal reef, a polarizer would potentially be great for that, but you would just have to carefully plan the flight. If you wanted to fly in a different direction, you would need to bring the drone back home to adjust or remove the polarizer to avoid uneven footage.

It's a good tool to have in the tool box, it just requires careful planning to get the most out of it and it's not something you want to just leave on and forget about like you can do with a standard ND filter. Most filter companies do a very poor job of explaining this to people and simply choose to market their PL filters as "vivid" or whatever, giving the customer the impression that they can just use them for any scenario and get better colors, which is far too simple and not the case.

RE: Linear vs Circular polarizers - A linear polarizer will only let light through that is polarized in the same direction as the filter is currently turned. Modern autofocus systems have problems with this, so you will basically never see anything other than a circular polarizer and there is no reason to ever use a liner polarizer in the context of taking photos/video. Circular polarizers have a layer behind the linear polarizing layer that "re-polarizes" the light in a different way so that the autofocus can function as intended.

Any polarizer you buy will likely have a rotating ring on the front, allowing you to adjust the strength of polarization, but that is totally useless when the drone is 400ft in the air haha. If you are using a polarizer on a DSLR or something, you simply reach forward and make the necessary adjustments, no big deal.

Also note that polarizers cut about a stop of light, so they are equivalent to a ND2, roughly speaking. Since you never would want to leave a polarizer on your lens all the time, you do not want to buy ND/PL combination filters *unless* you also have a non-polarized version of that same ND filter to use as well. If you want a polarizer, it does make sense to get a ND/PL combo if you are in a really bright area and have a fixed aperture drone, but just be aware that you will not want to use this filter very often due to the limitations above. Most of the time you will probably want to fly with regular ND's which have no such orientation limitations, and I think you will find that from high up in the air, polarizing is not as obvious as it is on the ground, but it is certainly still noticeable and YMMV there depending on conditions.

One final thing to note, is that using polarizers on very wide lenses (like 24mm on the Air2S) you can sometimes get an uneven ploarizing effect. This is typically most noticeable with blue skies, where the middle will be much darker than the edges. Polarizers just work better on longer focal length lenses, but most people want them for landscapes, which are typically done on wide angle lenses, so it's a bit of a compromise.

Sorry that was long and I rambled a bit, if you need clarity on anything just ask.

CanadaDrone, thank you so much for all the info!!! I feel like I've just gone to ND University with this thread. Great stuff. You have saved me a LOT of time. I actually feel like semi-knowledgeable now about ND filters and Polarizing filters and can make an informed purchase. Love the simple guidelines you provided.

Thanks!!!

 

[pommy]

What brand did you end up purchasing?

It's linked at the bottom of that post

 

[JetM]

It's linked at the bottom of that post

In this thread? Hmm....Maybe I missed it but didn't see it after reviewing all your post/responses in this thread.

 

[CanadaDrone]

CanadaDrone, thank you so much for all the info!!! I feel like I've just gone to ND University with this thread. Great stuff. You have saved me a LOT of time. I actually feel like semi-knowledgeable now about ND filters and Polarizing filters and can make an informed purchase. Love the simple guidelines you provided.

Thanks!!!

Happy to help. Best of luck and be sure to post if you run into any other questions.

 

[JetM]

Happy


Happy to help. Best of luck and be sure to post if you run into any other questions.

Will do. Thanks again for all your help!

 

[pommy]

In this thread? Hmm....Maybe I missed it but didn't see it after reviewing all your post/responses in this thread.

 

[JetM]

View attachment 136606

Thanks I missed that because I didn't recognize the brand. I'll check it out. Seems like at minimum you would want some protection over the drones lens/glass to protect from scratches if the lens is not something that could be easily replaced.
Cheers