Dear all,
For a research project, I need to track floating objects on the coast, and I want to cancel (or reduce) the reflection from the water surface in order for my computer vision software not to confuse the floating objects with reflections. I have the camera pointing down vertically and I will take still pictures of water only (and floating objects of course).   I was thingking to buy this: https://www.amazon.com/gp/produc ... ABSER5PUBOKRD&psc=1 but some people say that it is too heavy for the gimbal (not sure what they meant). I  want to achieve what it is done here (see at sec 34 how floaters are nicely visible, with polarizer, but not visible without): . I read polarizers only works at some specific angles. Would they work in my case? Which is your suggestion?
Thank you very much

A.

I read polarizers only works at some specific angles. Would they work in my case? Which is your suggestion?
To get the effect you are looking for, you need to correctly orient the polariser with respect to the sun.
With a handheld camera, thats no problem because if you move the camera it's easy to realign the polariser.
But when it's on a drone it would mean that to keep the effect for all photos the drone would have to be facing exactly the same way and that could be a problem.

How is it if you try always shooting obliques with the sun behind the drone and the camera facing the same direction as the light from the sun.
Does that cut reflections enough for your purposes?

I find it very hard to work with PL's.
The effect can really only be judged when you see the preview from 'up there'.
And that means getting down, adjusting, get up again, try again, fail, retry, etc. etc.

Looking straight down, there will be very little effect from the polariser, not worth bothering with, you need to be looking at reflections reflected by around 45 degrees at the water surface for it to be blocked by the filter.

Look up "Brewsters Angle" for more details, remembering that waves can produce all angles so unless it is mirror calm there will always be some effect and never a perfect effect.

For removing reflections from water, you will always want your filter orientated vertically, there is no need to adjust the filter angle depending on conditions.