ND filters numbers

[Greg Peter]

Hey guys,
I have a Mavic 3

I fly to Greece every summer between July - August. During the day the sun is very bright .

This past summer I decided to use an nd filter 16 as an around during the day. It seems the quality wasn’t good. Looked very burned.

Does anyone have a rule of thumb of what nd filter numbers to use during each part of the day? Is 32 too much for the day? And how about golden hour?

The second question is that when I press zoom x2 or 7, and when I move the Mavic towards the sun as it sets, the aircraft doesn’t go straight. It wobbles left and right and up and down . Even if I go very very slow. If I have it on the normal camera It flies straight, what can this be?

Best
Greg

 

[Meta4]

Does anyone have a rule of thumb of what nd filter numbers to use during each part of the day? Is 32 too much for the day? And how about golden hour?

You need to explain what you want the ND filters for.
If it's for stills, you don't need ND filters at all.

The second question is that when I press zoom x2 or 7, and when I move the Mavic towards the sun as it sets, the aircraft doesn’t go straight. It wobbles left and right and up and down . Even if I go very very slow. If I have it on the normal camera It flies straight, what can this be?

That sounds like obstacle avoidance.
It would be easy to test this by flying away from the sun or disabling OA and seeing if the issue is still there.

 

[Greg Peter]

You need to explain what you want the ND filters for.
If it's for stills, you don't need ND filters at all.

That sounds like obstacle avoidance.
It would be easy to test this by flying away from the sun or disabling OA and seeing if the issue is still there.

Thanks for the quick reply. The ND filters are for video

 

[SethB]

…I fly to Greece every summer between July - August. During the day the sun is very bright .

This past summer I decided to use an nd filter 16 as an around during the day. It seems the quality wasn’t good. Looked very burned.

Does anyone have a rule of thumb of what nd filter numbers to use during each part of the day? Is 32 too much for the day? And how about golden hour?…

It would really help to see an example of your “very burned” clips. Can you upload to youtube and share a link?

Were you using automatic exposure settings? What EV adjustment?
Were you using manual exposure settings? What aperture, ISO and shutter speed?

For southern Europe in August you might need 32 or even 64, depending on what you’re filming. If you’re not sure what you’re doing with manual exposure settings it may be best to use auto.

 

[Octavio]

Hey guys,
I have a Mavic 3

I fly to Greece every summer between July - August. During the day the sun is very bright .

This past summer I decided to use an nd filter 16 as an around during the day. It seems the quality wasn’t good. Looked very burned.

Does anyone have a rule of thumb of what nd filter numbers to use during each part of the day? Is 32 too much for the day? And how about golden hour?

The second question is that when I press zoom x2 or 7, and when I move the Mavic towards the sun as it sets, the aircraft doesn’t go straight. It wobbles left and right and up and down . Even if I go very very slow. If I have it on the normal camera It flies straight, what can this be?

Best
Greg

Hello #Greg Peter, regarding the ND Filters, you only need them for Video because of the rule of thumb you need to set your Shutter speed to double the framerate because we have the Aperture fixed at f2.8.
There are many ways you can calculate your Aperture in other to choose the correct ND filter.
You can use your Drone, or a Camera or Light Meter, to measure the correct settings. I like to use my Light Meter. I save on my Drone battery this way.
You need to put in Auto and your ISO at 100 for the best pictures. You know that your Aperture is fixed, mine at f2.8.
So, if it shows me a Shutter Speed of 2000/s and I want to use a framerate of 30fps I need my Aperture to be at 60/s so I need a ND32 = to 5 Stops VND filter.
Personally, I like to use Variable VND filter 2 to 5 and 6 to 9 stops. It gives me a nice margin and I don't often need to change my filters.
On my Mobile, I have an Exposure Calculator which makes life a lot easier for me. You can also print out a Chart for shutter speed values when using ND filters.
Remember that if you use the Auto setting without ND filter you will get a jerky Video when turning.

As to flying towards the sun! I suggest that you keep your sensor's lens clean.

 

[DARKSeifer]

It depends on the fixed aperture of your drone, and the intended shutter speed you want to use. You fix the shutter speed to whatever value you want (to get the amount of motion blur you desire) and leave the ISO on Auto (or fixed if you want to have more control).

You have to choose a filter that the brightest parts of the scene don't blow out at 100 ISO. If they blow out, you need to use a darker filter.

If the filter you choose is too dark, the exposure will never reach 100 ISO, so quality will be lower.

A good filter choice will use 100-200 ISO on the bright areas and increase to whatever it needs on the shadow (for example in FPV when you enter a building).

A bad filter choice will use 200+ ISO all the time and never go under 200 ISO.

On the Mavic 3 you can also play with the diaphragm, but going any closer than f/3.2 will reduce the quality because of the diffraction, so bear that in mind. The highest quality for the Mavic 3 is at f/3.2.

Finally, you only want to use an ND on photo for long exposures, which on drone are up to 3 seconds or so, past there trepidation will be quite visible, specially on windy days.

The second question is that when I press zoom x2 or 7, and when I move the Mavic towards the sun as it sets, the aircraft doesn’t go straight. It wobbles left and right and up and down . Even if I go very very slow. If I have it on the normal camera It flies straight, what can this be?

Maybe you have the obstacle avoidance set to Bypass instead of Brake, and it detects the sun as an obstacle.

 

[Meta4]

On the Mavic 3 you can also play with the diaphragm, but going any closer than f/3.2 will reduce the quality because of the diffraction, so bear that in mind. The highest quality for the Mavic 3 is at f/3.2.

This is nonsense.
The visible difference in quality at smaller apertures is negligible.
Use whatever aperture suits and you'll still get good images with the Mavic 3.

 

[Greg Peter]

It depends on the fixed aperture of your drone, and the intended shutter speed you want to use. You fix the shutter speed to whatever value you want (to get the amount of motion blur you desire) and leave the ISO on Auto (or fixed if you want to have more control).

You have to choose a filter that the brightest parts of the scene don't blow out at 100 ISO. If they blow out, you need to use a darker filter.

If the filter you choose is too dark, the exposure will never reach 100 ISO, so quality will be lower.

A good filter choice will use 100-200 ISO on the bright areas and increase to whatever it needs on the shadow (for example in FPV when you enter a building).

A bad filter choice will use 200+ ISO all the time and never go under 200 ISO.

On the Mavic 3 you can also play with the diaphragm, but going any closer than f/3.2 will reduce the quality because of the diffraction, so bear that in mind. The highest quality for the Mavic 3 is at f/3.2.

Finally, you only want to use an ND on photo for long exposures, which on drone are up to 3 seconds or so, past there trepidation will be quite visible, specially on windy days.



Maybe you have the obstacle avoidance set to Bypass instead of Brake, and it detects the sun as an obstacle.

YouTube link hey guys, thanks for all of your replies. I have uploaded a video on YouTube so you can see. This video was done on nd filter 16 in bright day light , 60 fps and shutter 120, white balance is auto and iso is auto as well. Just look how burned it it. Very bad quality . I don’t get it

 

[Greg Peter]

hey guys, thanks for all of your replies. I have uploaded a video on YouTube so you can see. This video was done on nd filter 16 in bright day light , 60 fps and shutter 120, white balance is auto and iso is auto as well. Just look how burned it it. Very bad quality . I don’t get it

You tube link

 

[MS Coast]

hey guys, thanks for all of your replies. I have uploaded a video on YouTube so you can see. This video was done on nd filter 16 in bright day light , 60 fps and shutter 120, white balance is auto and iso is auto as well. Just look how burned it it. Very bad quality . I don’t get it

You tube link

What do you mean by burned? Overexposed? The exposure in that clip looks quite good to me. What quality issues do you see?

If you're trying to take full control of the exposure, you need to set the ISO.

Are you using the exposure bias control?

 

[SethB]

hey guys, thanks for all of your replies. I have uploaded a video on YouTube so you can see. This video was done on nd filter 16 in bright day light , 60 fps and shutter 120, white balance is auto and iso is auto as well. Just look how burned it it. Very bad quality . I don’t get it

You tube link

The clip on Youtube is very helpful.

I downloaded it and brought it into Premiere Pro 2022 to analyze it and make adjustments.

My sense is that @Greg Peter does not like the appearance of the clip, feeling that it is overexposed ("burnt").

The scopes in Premiere's Lumetri Color filter show just very slight overexposure that is completely correctable in processing.

The OP may not wish to do any processing; my advice would be to reduce exposure by 1 stop - choose any of these methods:
(choose one!)
* Use an ND32 filter instead of ND16, keep all other settings as they are, or,
* If using automatic exposure, reduce the EV slider to -1, or,
* If using manual exposure set iso to 100 and shutter speed to 240, keeping other settings.

Any one of these methods will reduce exposure by one stop. Probably the 2nd choice is easiest.

***Feel free to ignore the rest of this post***
Note that choosing #3 above violates the "180 shutter rule", but that with this content there would be no perceivable change in motion blur.

Generally, beginners who want results now without processing should keep everything (except perhaps white balance) on auto, and consider adjusting the EV slider slightly if their images/clips are looking overexposed.

Here are some files. Not sure what order these will appear in.

unprocessed.grab.png
The 2-panel grab from Premiere shows the uncorrected footage on the right, and the slight overexposure on the scopes on the left which is indicated by the flat tops of the waveforms.

processed.grab.png
The 3-panel grab shows slight correction of white balance, saturation, exposure, shadows, highlights, and blacks with corresponding changes to the image and waveform. Note that the tops of the waveform are no longer flat, indicating that the overexposure in camera was slight and fully correctable. Whites are not "blown" or "clipped".

26 October 2023.png
The single image is an export from Premiere of the corrected version.

Note also that what I've done are slight corrections. This clip could be further graded by quite a bit if desired.

 

[Greg Peter]

The clip on Youtube is very helpful.

I downloaded it and brought it into Premiere Pro 2022 to analyze it and make adjustments.

My sense is that @Greg Peter does not like the appearance of the clip, feeling that it is overexposed ("burnt").

The scopes in Premiere's Lumetri Color filter show just very slight overexposure that is completely correctable in processing.

The OP may not wish to do any processing; my advice would be to reduce exposure by 1 stop - choose any of these methods:
(choose one!)
* Use an ND32 filter instead of ND16, keep all other settings as they are, or,
* If using automatic exposure, reduce the EV slider to -1, or,
* If using manual exposure set iso to 100 and shutter speed to 240, keeping other settings.

Any one of these methods will reduce exposure by one stop. Probably the 2nd choice is easiest.

***Feel free to ignore the rest of this post***
Note that choosing #3 above violates the "180 shutter rule", but that with this content there would be no perceivable change in motion blur.

Generally, beginners who want results now without processing should keep everything (except perhaps white balance) on auto, and consider adjusting the EV slider slightly if their images/clips are looking overexposed.

Here are some files. Not sure what order these will appear in.

unprocessed.grab.png
The 2-panel grab from Premiere shows the uncorrected footage on the right, and the slight overexposure on the scopes on the left which is indicated by the flat tops of the waveforms.

processed.grab.png
The 3-panel grab shows slight correction of white balance, saturation, exposure, shadows, highlights, and blacks with corresponding changes to the image and waveform. Note that the tops of the waveform are no longer flat, indicating that the overexposure in camera was slight and fully correctable. Whites are not "blown" or "clipped".

26 October 2023.png
The single image is an export from Premiere of the corrected version.

Note also that what I've done are slight corrections. This clip could be further graded by quite a bit if desired.

God bless you, thank you for your time. You are very kind
Best regards from Denmark
Greg

 

[jephoto]

hey guys, thanks for all of your replies. I have uploaded a video on YouTube so you can see. This video was done on nd filter 16 in bright day light , 60 fps and shutter 120, white balance is auto and iso is auto as well. Just look how burned it it. Very bad quality . I don’t get it

You tube link

You are just over exposed. Just setting your exposure to “Auto” doesn’t mean it’s going to be perfect. Your camera or sensor takes in the whole scene and tries to give you an average exposure equivalent to 18% gray.
You have blue sky and dark blue water in this scene so your camera is giving an average exposure that is a bit too hot - or over exposed for the scene.
Bring up the Histogram- always keep it on and before you start filming, adjust the exposure so the graph doesn’t hit the right hand side.
Which is white with no detail.
If on auto that means adjusting the compensation to a minus number.

Using auto will cause your exposure to go up and down depending on where you point it.
Sometimes that’s good if the light is changing a lot / like with fast moving clouds that go in and out of the sun, but in a scene like you’re showing here, you should put the drone up, perhaps put it on auto to get a base exposure, then switch to manual and adjust it to where you want it. Then start filming. That way you will have a consistent exposure for the scene, and you were in control, not the camera.

The big advantage you have with the Mavic three is the variable aperture. If it’s a little too hot, even with the ND filter on, usually you can stop down a bit on your aperture to give you a good exposure without having to return home and put on another ND filter.
But the optimum aperture for that lens is around F4.0. For the maximum sharpness, but truthfully, you’ll be hard-pressed to see the difference if you have to go up f8.0 for a while.
You have the controls, use them…

I recently was filming a School, and it was cloudy when I started out, but then the sun came out and it got very bright and I had to go to F8 and f11 for a few clips because I had a ND 16 filter on.
The clips looked fine.

 

[Greg Peter]

You are just over exposed. Just setting your exposure to “Auto” doesn’t mean it’s going to be perfect. Your camera or sensor takes in the whole scene and tries to give you an average exposure equivalent to 18% gray.
You have blue sky and dark blue water in this scene so your camera is giving an average exposure that is a bit too hot - or over exposed for the scene.
Bring up the Histogram- always keep it on and before you start filming, adjust the exposure so the graph doesn’t hit the right hand side.
Which is white with no detail.
If on auto that means adjusting the compensation to a minus number.

Using auto will cause your exposure to go up and down depending on where you point it.
Sometimes that’s good if the light is changing a lot / like with fast moving clouds that go in and out of the sun, but in a scene like you’re showing here, you should put the drone up, perhaps put it on auto to get a base exposure, then switch to manual and adjust it to where you want it. Then start filming. That way you will have a consistent exposure for the scene, and you were in control, not the camera.

The big advantage you have with the Mavic three is the variable aperture. If it’s a little too hot, even with her in the filter on, usually you can stop down a bit on your aperture to give you a good exposure without having to return home and put on another ND filter.
But the optimum aperture for that lens is around F4.0. For the maximum sharpness, but truthfully, you’ll be hard-pressed to see the difference if you have to go up f8.0 for a while.
You have the controls, use them…

I recently was filming a School, and it was cloudy when I started out, but then the sun came out and it got very bright and I had to go to F8 and f11 for a few clips because I had a ND 16 filter on.
The clips looked fine.

Thanks a lot for this extensive reply I truly appreciate it. I need to clarify that I was on manual this summer. I did exactly that, I put everything on auto, then switch to manual. But don’t you think an ND 32 would be better here than the 16? As it is very bright in Greece in July August with temperatures at 40oC or 120F.

So should I put the exposure even down? Instead of 120 should I go to 240 since I’m on 60fps? Or should I raise my aperture ? I mean I can’t bring my iso less than 100. What do you suggest ?
Best
Greg

 

[Ty Pilot]

So should I put the exposure even down? Instead of 120 should I go to 240 since I’m on 60fps? Or should I raise my aperture ? I mean I can’t bring my iso less than 100. What do you suggest ?
Best
Greg

@jephoto gave you the correct answer: You have a Mavic3 with adjustable aperture, use it. You can adjust the exposure down with the aperture, keep ISO at 100 and run shutter at double your frame rate, then if you are over exposed with an ND 16 you can stop down the aperture to as much as f8 to get the exposure. It was also mentioned to use the histogram, that is also advised.

I don't have a Mavic3 but I do shoot with an M2Pro and it also has a sweet spot of around an f4 aperture but can be down to an f8 and still give great results. Shooting video on bright days; run shutter priority, set ISO as low as possible and use an ND/aperture combo as close to what you desire, then make adjustments with the aperture for correct exposure.

Also, please understand the term "Exposure" is the yield from three separate settings, so when you say "should I set the exposure down" - that is an open ended question - in your case: yes, but use the aperture to do it.

 

[Greg Peter]

@jephoto gave you the correct answer: You have a Mavic3 with adjustable aperture, use it. You can adjust the exposure down with the aperture, keep ISO at 100 and run shutter at double your frame rate, then if you are over exposed with an ND 16 you can stop down the aperture to as much as f8 to get the exposure. It was also mentioned to use the histogram, that is also advised.

I don't have a Mavic3 but I do shoot with an M2Pro and it also has a sweet spot of around an f4 aperture but can be down to an f8 and still give great results. Shooting video on bright days; run shutter priority, set ISO as low as possible and use an ND/aperture combo as close to what you desire, then make adjustments with the aperture for correct exposure.

Also, please understand the term "Exposure" is the yield from three separate settings, so when you say "should I set the exposure down" - that is an open ended question - in your case: yes, but use the aperture to do it.

Thanks a lot

 

[jephoto]

Thanks a lot for this extensive reply I truly appreciate it. I need to clarify that I was on manual this summer. I did exactly that, I put everything on auto, then switch to manual. But don’t you think an ND 32 would be better here than the 16? As it is very bright in Greece in July August with temperatures at 40oC or 120F.

So should I put the exposure even down? Instead of 120 should I go to 240 since I’m on 60fps? Or should I raise my aperture ? I mean I can’t bring my iso less than 100. What do you suggest ?
Best
Greg

Absolutely in your case the 32 would be better.
The situation I was talking about. It was cloudy when I started out, and then the sun came out. But I didn’t have to land and change filters because I could stop down my aperture.

But for optimum optical quality, the best aperture is between F4 and F5.6.
Your goal, if it all possible, if you’re trying to do the “correct“ shutter speed is 2x your frame rate, and aperture of F4.0-5.6

Whatever ND strength you need to get there.

There’s lots of controversy on whether it’s necessary to get a correct frame rate to shutter speed. If you’re high up and there aren’t a lot of fast moving objects in your frame, it’s not as critical. If you’re closer to objects that are moving then if your shutter speed is too high, will appear a bit jittery. The formula for shutter/frame rate is to give a slight (very slight) motion blur to each frame that makes the video appear more natural and smooth.

Also getting back to using the Histogram, you always want to preserve your Highlights. If a clip is a bit dark/underexposed, you can brighten it up in post- but if you blow out your highlights, it’s just gone. No detail to work with.

 

[Greg Peter]

Absolutely in your case the 32 would be better.
The situation I was talking about. It was cloudy when I started out, and then the sun came out. But I didn’t have to land and change filters because I could stop down my aperture.

But for optimum optical quality, the best aperture is between F4 and F5.6.
Your goal, if it all possible, if you’re trying to do the “correct“ shutter speed is 2x your frame rate, and aperture of F4.0-5.6

Whatever ND strength you need to get there.

There’s lots of controversy on whether it’s necessary to get a correct frame rate to shutter speed. If you’re high up and there aren’t a lot of fast moving objects in your frame, it’s not as critical. If you’re closer to objects that are moving then if your shutter speed is too high, will appear a bit jittery. The formula for shutter/frame rate is to give a slight (very slight) motion blur to each frame that makes the video appear more natural and smooth.

Also getting back to using the Histogram, you always want to preserve your Highlights. If a clip is a bit dark/underexposed, you can brighten it up in post- but if you blow out your highlights, it’s just gone. No detail to work with.

Hi again, thanks a lot, when you mean too high shutter speed, if my fps is 60 and shutter speed is 120, if I boost it higher to 240 will that make it more jittery , or if I bring it lower to under 120?

 

[Greg Peter]

Hi again, thanks a lot, when you mean too high shutter speed, if my fps is 60 and shutter speed is 120, if I boost it higher to 240 will that make it more jittery , or if I bring it lower to under 120?

Also, how would we know if the aperture is correct, with the correct shutter speed contra to fps and nd filters. Is it trial and error, meaning o shoot, then check in post if it’s correct? Or do we put auto time if the correct setting fit? You get my point? You’re saying to play with the nd filters to get the correct and ideal setting of x2 shutter from the fps, and using nd filters to get there. But to get there is that simply trial and error ?

I always thought that the lower the shutter speed like 1/60 will give more blur than 120, or is gitter and blue are the same right ?

 

[jephoto]

Hi again, thanks a lot, when you mean too high shutter speed, if my fps is 60 and shutter speed is 120, if I boost it higher to 240 will that make it more jittery , or if I bring it lower to under 120?

More jittery. For each of those 60 frames every second, you’ll have a sharper motion frozen image than if you were at 1/120 sec.

Shutter speed is the time the shutter opens & closes FOR EACH FRAME.

So , yes, if you set a 60FPS rate, 1/120 sec shutter speed is correct.
For 120FPS, 1/250 sec shutter. (For real slow motion effect)

And that’s another way to deal with real bright days or scenes like your Greece footage. Set a 60FPS, 1/120sec, 100iso, and ND32 and you’ll have no problem keeping your shutter and aperture where you want them.

There’s some excellent youtube vids about Time lapse shooting where he sets his shutter speed to like 1/8 or 1/4 sec so each frame has a definite motion blur and when strung together into a video looks creamy smooth with cars and other moving objects just look dreamy and flow like a River.

If he’d done every frame at 1/60 sec it wouldn’t blend as well.
Same principle.
Here’s an excellent video about this