Hi, I have some filters for my Phantom 3 pro, they are: MC UV, MRC UV, CPL, and ND8. Question is, how do I use them, I know I fit them over the lens but for what purpose ? I am no David Bailey so I dont know what the effects would be. Can anyone tell me ? Cheers.  Colin.

Hello and good day Colin. Thank you for reaching out and for the inquiry. The ND filter reduces the amount of light coming into the sensor. It gives you the freedom to create your own work by allowing more control of the camera's aperture, exposure time and sensor sensitivity settings, it also reduces light by 3 stops to effectively avoid over exposure, so that you can capture great photos in a wider range of environments. I hope this can help. Thank you.

DJI Stephen Posted at 5-18 14:28
Hello and good day Colin. Thank you for reaching out and for the inquiry. The ND filter reduces the amount of light coming into the sensor. It gives you the freedom to create your own work by allowing more control of the camera's aperture, exposure time and sensor sensitivity settings, it also reduces light by 3 stops to effectively avoid over exposure, so that you can capture great photos in a wider range of environments. I hope this can help. Thank you.

Many thanks.

ND or Neutral Density filters are like sunglasses for your camera.  The number denotes how strong they are - -ND4 are pretty mild, ND8 is twice as strong, ND16 is darker still.
CPL is Circular Polarising.  It is a polariser for eliminating glare (e.g. seeing fish under water or passengers inside a car, rather than getting a mirror-like glare off the surface of the water/glass.  In a normal polarising lens you need to rotate one ring to align the "slits" in the filter to line up with the waves of light coming from the object.  They are made up of parallel lines of slits.  A CPL filter is made up of concentric rings of "slits", so it works in any orientation.  It is better for a camera like we use in aerial photography because it doesn't need realigning if it moves off vertical axis or rotates slightly (which will be enough to upset the linear type).  Short answer, it is for eliminating glare, I pretty much fly everywhere using one.
UV is for blocking ultraviolet light.  It can make a difference with capturing colours accurately, often you cannot see much with your eye.  It tends to reduce the blueness of daylight colour temperature, and is more noticeable if you are doing landscape photography.  Photographers tend to use one on the end of their expensive lenses as protection, as cheap sacrificial glass in case of dust, sandblasting and scratches.  Whack one on for protection if you aren't using anything else.
MC means multi-coated, meaning the glass has multiple layers of film which assist in transmitting light cleanly.  MRC is multi resistive coated, same thing but "harder" and more resistant to getting damaged.  Probably more expensive.  Very hard to determine if it is worthwhile at all or just snake oil.

I know the purists will tell me I'm wrong .... but here goes :

I have a set of CPL, ND4 and ND8 ....
The CPL I never use ... maybe one day I will experiment.
The ND4 very rarely. I keep for days that are light but dull.
The ND8 is virtually a permanent fitting as I do a lot of landscape / river stuff and I find it increases the contrast ... makes my blues etc. more vivid, less washed out on those bright summer or snow covered days.

Why they work ... how they work ... I am no David Baliey either ... I know the ND's reduce the light entering ... but that's as far as I know and need.

Pitsmoor Col Posted at 5-18 14:53
Many thanks.

You are very much welcome Colin. Have a safe and happy flying always.