ND Filter for Tropical Area (Hawaii)

[Grakken]

Hello All,

So I have the skyreat ND-4, 8, 16 (and PL lenses in same#'s). I suppose I like them but I have nothing to compare them too. I usually just fly with the 16 or the 16PL (Near a lake) all the time during the day. My question is, do you think I will need to get the 32 or 64 (and PL) for Hawaii? I am no photog expert but even flying around my house (socal) i *think* that the 16's may not be enough on some days but what do i know. I try to stick to the 1/50 speed but I notice ive been shooting in AF (never does 1/50 lol)more often as to not deal with all the settings but will (try)do more manual when I am there. Thank you for any input.

 

[ff22]

I will bump your question as I'm interested in what some of our more knowledgeable video folks think.

 

[CanadaDrone]

I go to Hawaii quite a bit and I use a ND16 most often (F2.8 / ISO 100 / 1/60 - 1/100 shutter). You sometimes need a ND32 for bright midday sun around the water if you want to keep the shutter speed at 1/60 (depends on the day). ND8 was perfect for overcast/waterfalls. You won't need the ND4 at all unless you fly at dusk/dawn. I've never needed a ND64.

If you are OK raising your shutter from 1/60 to 1/120 then that is the same as going from a ND16 --> ND32, all else equal.

Be careful with the PL filters because of the way polarization works - strongest 90 degrees to the sun and completely eliminated 180 degrees from the sun. You need a carefully planned flight path with zero deviation if you don't want uneven footage, which is easy to get in Hawaii with such strong sunlight and water everywhere. They have their place for sure, but you really need to understand how they work to avoid uneven footage.

 

[Grakken]

Thank you CD, so what I am hearing is that the PL is ineffective with the sun at the AC's back and that the light (sun) should be 90 deg. That is good to know. What about getting a shot while pointing at the sun...for instance a horizon shot towards the sun either directly facing, or slightly off center? Hope that makes sense....and why wouldn't the PL just be coating the whole lense? I think i read that you have to "adjust" the PL lens on the camera to get it "right". Doesn't make sense.

 

[CanadaDrone]

Thank you CD, so what I am hearing is that the PL is ineffective with the sun at the AC's back and that the light (sun) should be 90 deg. That is good to know. What about getting a shot while pointing at the sun...for instance a horizon shot towards the sun either directly facing, or slightly off center? Hope that makes sense....and why wouldn't the PL just be coating the whole lense? I think i read that you have to "adjust" the PL lens on the camera to get it "right". Doesn't make sense.

Any time the sun is 180 degrees from the polarizer, the polarization will be zero (there is no polarization shooting straight into the sun either). The level of polarization steadily increases from 180 degrees (zero polarization) until it reaches 90 degrees to the sun (maximum polarization). What you generally don't want is a noticeable change in exposure in the middle of your footage, and you will get that if you alter your course with a PL filter installed - that's why the flight path needs to be well planned for optimal use of the PL.

A quick and dirty method is to point your finger at the sun in a right-angle "gun" or "L" shape along with your thumb. Keeping your pointer finger at the sun, where ever your thumb is pointing while rotating around the axis created by your pointer finger, you will have maximum polarization. For example if the sun is directly overhead, it will be relatively easy to get good polarization in multiple directions if you are shooting toward the horizon. If the sun is barely above the horizon, it's completely different as the maximum polarization angles will be straight up and straight down.

For polarizers that allow you to rotate and adjust them, it's kind of pointless on a drone because you can't change it in the air anyway, but that changes the strength of the polarization. The point of maximum possible polarization does not change, which remains 90 degrees to the sun, but you can use it to reduce the level of polarization. Sometimes you may not want to remove reflections, for example if you have some nice orange clouds reflecting off calm water during a sunset.

The PL coating is on the entire lens and affects the entire frame, the only thing that really matters is your orientation to the sun. If you have a pair of polarized sungalsses, go outside while the sun is up and tilt your head 90 degrees - aside from looking strange to anyone watching, you will see a very noticeable difference.

 

[Grakken]

Good info thank you! So do you find yourself flying (or filming) in straight lines when you have a PL installed? Then taking a bunch of separate "straight line" clips and stitching them in post? Seems to me unless you are getting very specific scenes or shots, it may be best just to leave the PL off.

 

[CanadaDrone]

Good info thank you! So do you find yourself flying (or filming) in straight lines when you have a PL installed? Then taking a bunch of separate "straight line" clips and stitching them in post? Seems to me unless you are getting very specific scenes or shots, it may be best just to leave the PL off.

You're welcome. Honestly I don't use PL's much, I am extremely picky about my video quality and using a PL means I can only fly one very specific flight path before returning 'home' to change filters. If the sun is directly overhead you have a little more leeway, but while you change directions you can't be filming or it will still look uneven. The catch is that there is no way to replicate a PL effect in software, not even close, so if you want that effect there is only one way to get it. In tropical areas like Hawaii, everything still looks pretty great from the air even without a PL, you can usually still see the reefs through the water, etc. and reflections are generally a lot less distracting from 100-200ft up. If I am on my own and I have the time I will try out the PL but usually I am with other (far less patient) people haha, so I like the flexibility of a standard ND filter.

Generally I don't recommend you use a PL unless you want a very specific shot, and yes you would be doing straight-line runs and then stitching them after into one clip or whatever you like - basically you would be editing out any time spent turning or changing direction, and even then, the new direction will look completely different if the sun isn't directly overhead or if your filter isn't oriented properly.

 

[W2EJ]

You're welcome. Honestly I don't use PL's much, I am extremely picky about my video quality and using a PL means I can only fly one very specific flight path before returning 'home' to change filters. If the sun is directly overhead you have a little more leeway, but while you change directions you can't be filming or it will still look uneven. The catch is that there is no way to replicate a PL effect in software, not even close, so if you want that effect there is only one way to get it. In tropical areas like Hawaii, everything still looks pretty great from the air even without a PL, you can usually still see the reefs through the water, etc. and reflections are generally a lot less distracting from 100-200ft up. If I am on my own and I have the time I will try out the PL but usually I am with other (far less patient) people haha, so I like the flexibility of a standard ND filter.

Generally I don't recommend you use a PL unless you want a very specific shot, and yes you would be doing straight-line runs and then stitching them after into one clip or whatever you like - basically you would be editing out any time spent turning or changing direction, and even then, the new direction will look completely different if the sun isn't directly overhead or if your filter isn't oriented properly.

Thank you @CanadaDrone, Yours is the kind of response for information that makes these forums a value. Well written, clear and accurate.

 

[DanMan32]

Usually rule of thumb is to target shutter speed 2x fps. For stills, you probably don't need ND filters, unless you're looking for some motion blur in your photos.

 

[CanadaDrone]

Thank you @CanadaDrone, Yours is the kind of response for information that makes these forums a value. Well written, clear and accurate.

Your'e very welcome - if there is anything else you think I can help with feel free to drop me a line.

 

[RyanSweeney]

Your'e very welcome - if there is anything else you think I can help with feel free to drop me a line.

What brand ND filters do you use? I know PolarPro are the go-to filters, but are they THAT much better than brands such as Freewell?

 

[CanadaDrone]

What brand ND filters do you use? I know PolarPro are the go-to filters, but are they THAT much better than brands such as Freewell?

I use Polar Pro Cinema series and was very happy with them. My personal outlook is that their premium to the cheap/knockoff filters is not enough to take the risk while on vacation, where I may not be able to easily find a replacement. Lifetime warranty is nice, and their cost relative to the drone was small enough that I went with the "safe" choice. They are also guaranteed not to interfere with gimbal calibration/operation, which has been an issue in the past. That is not to say other filters won't do the job, I just can't vouch for them personally. Whatever you buy make sure they are using quality borosilicate glass, are multi-coating both sides of the glass, have a quality aluminium frame, and are guaranteed to not interfere with gimbal calibration.

Freewill in particular is a low-cost/low quality accessory maker for camera stuff, so based on that I probably wouldn't buy their filters but I also can't say for sure they aren't as good as anything else. It likely depends how picky you are (I am extremely picky). I would want to know exactly how they are made before using them, but if you just buy from Amazon or something you can return them if you aren't happy so there is no real risk there.

 

[RyanSweeney]

Thank you. I did quite a lot of research and pulled the trigger on the Freewell this morning. They too have double-sided, multi-coated premium glass, a lifetime warranty, and are guaranteed to not interfere with the gimbal.