Are ND Filters Worthwhile Considering the Limitations ?

Alpha Fox · Sep 12, 2016

I understand the need to have a better cinematic image quality by going manual exposure and adding a ND filter , but it seems to me that the only adjustable parameters are ISO and shutter speeds.

If I want to shoot at 1/60 for 30fps, if I have figured the correct ND filter, then my only adjustable is the ISO, is that correct?

Can someone enlighten me how they work the ND filters in the shooting? Exposure changes in relation to the sun's position, so it's a constant variable.

I can see the value of using ND filters, but wondering how much control we can really have over the factors that determine proper exposure and video quality, since lens aperture is not adjustable.

Thanks.

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Richard R · Sep 12, 2016

ISO, Shutter speed and EV are all adjustable although there is some interdependence between them. For video, the 'recommended' value is ISO=100, shutter = 1/60 (assuming 30 fps) and the EV at 0. for me, an ND of 8 on a bright sunny day here in west central Ohio works. The 1/60 shutter gives you just enough blur in the video for the eye to see smooth motion. For still, of course, you don't want blur so crank the shutter up and, usually, take the ND off. check what the image looks like in auto mode and if you don't like it, switch to manual and play with the shutter sped. Try to keep the ISO low to reduce graininess.

Alpha Fox said:
Exposure changes in relation to the sun's position, so it's a constant variable.

Sun position is going to be a bear to control. you often don't have control of where you are shooting from or the time of day. Ideal position will depend on the shot and the effect that you want. shadow positions, etc. are all factors that you have to be aware of just like when shooting with a handheld camera. Do like the pros do and bracket you shots.

Alpha Fox · Sep 12, 2016

Thanks Richard. I often have to shoot still and motion on same flight, so that kinda eliminates the ND unless wanna do separate flights.
From the tests flights I've run, the video quality without the ND adequate for web uses with some further image processing, but still would like to test the NDs.
You mentioned that you use the ND8, the set I'm thinking of ordering comes in 16, 32,64, do see any issue not having the 8?

Thanks

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GMack · Sep 12, 2016

I made a chart that I carry in the bag to figure out which filter based on what the DJI Go exposure is telling me (I shoot manual mode.). Here is the post: 32 ND filter for Phantom 4? It's made for the 1/24-1/25 shutter speed and you can bump up the speeds on the right by a third and should be good for 1/60 sec. I'm using the free DaVinci Resolve 12.5 for editing and the better 4K 1/60 speed version is locked (?) to their $$$ premium one so I shoot slower frame speeds of 24-25 for their free version.

Also, the P4 lens is fairly wide angle so you can get away with a slower shutter speed even with the ND filter installed. Used to be some old rule of 24mm would be no slower than 1/25, a 50mm no slower than 1/50, 300mm no lower than 1/300, etc. so even a 1/50 sec. shutter is good enough for still or video. Plus, the active gimbal is a lot smoother than you holding it. Some report doing of shots at 8 seconds that looked pretty good, albeit 2 seconds might be better. You can try it and see, or do a burst exposure if uncertain and weed through them or perhaps stack them as doing an HDR, etc. which also can sharpens them up a bit.

Teo Morabito · Sep 12, 2016

Don't be scared of getting an nd32 filter,
You will find its the most useful one in day time.

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Suhail78 · Sep 13, 2016

GMack said:
I made a chart that I carry in the bag to figure out which filter based on what the DJI Go exposure is telling me (I shoot manual mode.). Here is the post: 32 ND filter for Phantom 4? It's made for the 1/24-1/25 shutter speed and you can bump up the speeds on the right by a third and should be good for 1/60 sec. I'm using the free DaVinci Resolve 12.5 for editing and the better 4K 1/60 speed version is locked (?) to their $$$ premium one so I shoot slower frame speeds of 24-25 for their free version.

Also, the P4 lens is fairly wide angle so you can get away with a slower shutter speed even with the ND filter installed. Used to be some old rule of 24mm would be no slower than 1/25, a 50mm no slower than 1/50, 300mm no lower than 1/300, etc. so even a 1/50 sec. shutter is good enough for still or video. Plus, the active gimbal is a lot smoother than you holding it. Some report doing of shots at 8 seconds that looked pretty good, albeit 2 seconds might be better. You can try it and see, or do a burst exposure if uncertain and weed through them or perhaps stack them as doing an HDR, etc. which also can sharpens them up a bit.

Would you be willing to share that chart with us?

GMack · Sep 13, 2016

Suhail78 said:
Would you be willing to share that chart with us?

It's here: 32 ND filter for Phantom 4?

See the attached JPG in the above link.

Loz · Sep 13, 2016

The chart was linked to a few posts above [emoji6]

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BigAl07 · Sep 13, 2016

Alpha Fox said:
Thanks Richard. I often have to shoot still and motion on same flight, so that kinda eliminates the ND unless wanna do separate flights.
From the tests flights I've run, the video quality without the ND adequate for web uses with some further image processing, but still would like to test the NDs.

Adequate won't set you apart from the rest. Once you start trying to make $$ from your video your clients may reject some of your work if you're not shooting correctly. I've had one client call me to the carpet for shooting with no filter but once I explained what they were looking at is exactly what the OTHER client had requested they were good to go.

I often shoot video and stills from the same flight you just have to make the needed adjustments. It's not ideal but for many cases it comes out very nice. Ideally you land, remove the ND, then go grab your stills. I've actually thought about grabbing another UAS to have one set up for stills and one for video.

Nickster · Sep 13, 2016

Good discussion. I like Allen's idea. Maybe the extra bird should be my excuse for an inspire!

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Trinimon · Sep 13, 2016

If you're shooting 1/60", 30fps @ISO100, just up the ISO to 200 and shoot at 1/120" which is fast enough esp for a wide angle lens, to get good pics from a camera that's not pin-sharp to begin with. There's not a whole lot of noise at ISO200. I'm iffy on ISO400 but would use it in a pinch if it meant missing a shot to having one.

Well, other than landing the bird and removing the filter.

Alpha Fox · Sep 14, 2016

Thanks everyone for the great info on the filters. Been debating wether I needed them or not, but now I can see it is a must for better quality video.

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Suhail78 · Sep 14, 2016

I bought these today, they gave me 10% off for signing up for their newsletter, and they threw in a free 6 lens case, and a gimbal lock that works with the new lenses. Cant wait to get them and try the new lenses!!

DJI Phantom 4 / Phantom 3 Professional Filter 6-Pack

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aaronrivera · Sep 16, 2016

How come no one here has used a variable nd filter?... i have!! Its 2-400.. i dnt need to swap it out i just turn the dial to adjust.

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Trinimon · Sep 16, 2016

Who makes a variable ND filter for the Phantom?

GMack · Sep 16, 2016

Trinimon said:
Who makes a variable ND filter for the Phantom?

Neewer and Drone-World sell them. They are quiet heavy though and can overload the gimbal. Amazon has some reviews on them where people get uneven density in moving sky scenes (Typical with polarizers.), color casts, and also a bad dark smuggy X that can occur with doubling of polarizing glass at darker settings like this guy shows:

Variable Neutral Density Filter Issue - Photo.net Accessories - Filters, Bags, Tripods Forum

Best to avoid, imho, and go with a straight ND filter.

WetDog · Sep 16, 2016

aaronrivera said:
How come no one here has used a variable nd filter?... i have!! Its 2-400.. i dnt need to swap it out i just turn the dial to adjust.

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Have one (Freewell), I'm playing around with it. Optically it's fine. It is a bit easier to use than swapping out single value filters. You can point the drone towards a representative lighting situation and dial in the shutter speed and ISO. But this points out the major issue with ND filters - you either work your scene so the lighting stays pretty constant or you accept shutter speeds that are 'non optimal'.

I like to fly around mountain peaks - the lighting is changing rapidly. It takes significant battery to get to the spot so even with stable lighting I can't run back, stick on the right filter and shoot. So I guess.

If you are shooting a more controlled scene, say a real estate video without wisps of fog floating through the property, you can really adjust the shooting parameters closely. YMMV.

aaronrivera · Sep 16, 2016

I too have the freewell and no problem so far. But must say i had one other brand that was too heavy n it didnt work out. So wasted that one. Freewell brand is good and light been using 3 months now!

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WetDog · Sep 16, 2016

aaronrivera said:
I too have the freewell and no problem so far. But must say i had one other brand that was too heavy n it didnt work out. So wasted that one. Freewell brand is good and light been using 3 months now!

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The only problem I've had with the Freewell is that it is somewhat bigger than the Polar Pro filters so I had to fashion another gimbal clamp.