CPL Ghosting in Images

[DroneToJoy]

Hi all

So Im trying out my CPL filter from Skyreat on my DJI Mini 2 and looking at my images (I use AEB) I just noticed many top down shots have a ghosted image of the subject near the subject. The CPL was fitted snugly onto the lens (I made sure) but even when images were take from 45 degrees the ghosting appears further along the image.

Can anyone give me possible reasons for this?

Adam

 

[Meta4]

Hi all

So Im trying out my CPL filter from Skyreat on my DJI Mini 2 and looking at my images (I use AEB) I just noticed many top down shots have a ghosted image of the subject near the subject. The CPL was fitted snugly onto the lens (I made sure) but even when images were take from 45 degrees the ghosting appears further along the image.

Examples?

 

[DroneToJoy]

Attached is an example of the ghosting that appears

 

[Dave Maine]

Does it only happen with the filter on? If so the filter itself is the problem. The problem is created by reflections in the optical path someplace. Fingerprints and dirt are the usual problems. Have you removed all plastic sheets or protectors that come with the products? Plastic thin films used to protect lens surfaces during shipment could cause this as well.

 

[Meta4]

Can anyone give me possible reasons for this?

It's obviously a reflection on one of the layers of the filter.
Incidentally polarising filters are of no use if your are shooting downwards.

 

[DroneToJoy]

The filter was super clean and carefully fitted, which makes it odd.

I thought with CPL I could use it at any angle but good to know.

Appreciated.
Adam

 

[Meta4]

The filter was super clean and carefully fitted, which makes it odd.

It's got multiple layers of glass and you're getting a reflection on one of them.

 

[Interficiam Stercore]

I use CPL filters on all me drones. I never noticed this ghosting effect, but I've never tried taking straight down shots with the CPL on or shots that poinnt directly at something, I usually take shots at angles. I guess a horizon shot would be considered straight on kinda, but I never see any ghosting. Maybe you should order another CPL from a different manufacturer. I've used Freewell, PGY TECH, and moment.

 

[vindibona1]

Are you getting the same effect when the camera is pointed less straight down? The only think I can think of is that it is refraction from the angle of the light striking the filter's surface. Have you tried using a lens hood? FWIW, I almost always put a lens hood on my Mini, if nothing else as a gimbal protector to take the brunt of inadvertent forward contact.

 

[Interficiam Stercore]

Are you getting the same effect when the camera is pointed less straight down? The only think I can think of is that it is refraction from the angle of the light striking the filter's surface. Have you tried using a lens hood? FWIW, I almost always put a lens hood on my Mini, if nothing else as a gimbal protector to take the brunt of inadvertent forward contact.

I tried a few straight down shots over water with some bright areas like the boat in you picture. That was with an air 2S. No ghosting. How does your cpl fit on the mini? On the mini 1 it clipped on, over the uv filter. So, on the mini 1, their was the cpl, the uv filter and then the lens. That's 3 layers for the light to go through. Does the mini 2 cpl filter replace the UV filter that comes with the drone or does it clip on over it like the mini 1 cpls do.?

 

[vindibona1]

I tried a few straight down shots over water with some bright areas like the boat in you picture. That was with an air 2S. No ghosting. How does your cpl fit on the mini? On the mini 1 it clipped on, over the uv filter. So, on the mini 1, their was the cpl, the uv filter and then the lens. That's 3 layers for the light to go through. Does the mini 2 cpl filter replace the UV filter that comes with the drone or does it clip on over it like the mini 1 cpls do.?

To be honest I have no filters for my Mini (yet). I have them for my Mavic2pro. ReHowever I have not used the cpl filters yet. Only ND or gradients. The M2 is so much easier to work with as it has a variable aperture.

 

[DroneToJoy]

I tried a few straight down shots over water with some bright areas like the boat in you picture. That was with an air 2S. No ghosting. How does your cpl fit on the mini? On the mini 1 it clipped on, over the uv filter. So, on the mini 1, their was the cpl, the uv filter and then the lens. That's 3 layers for the light to go through. Does the mini 2 cpl filter replace the UV filter that comes with the drone or does it clip on over it like the mini 1 cpls do.?

I have the Skyreat CPL lens. Clips directly over the lens. You can adjust it by rotating the lens but that's about it. Seems the ghosting was on all top downs which I'm aware I can't do now if I use this lens. It unfortunate for me as I'm going to try (hopefully) get some whale shots next weekend nearby and don't want to risk taking photos where this may happen and I have to keep changing angles.

 

[Meta4]

It unfortunate for me as I'm going to try (hopefully) get some whale shots next weekend nearby and don't want to risk taking photos where this may happen and I have to keep changing angles.

You don't need a polariser to shoot whales.
All you need to do is make sure the sun is behind the drone and you'll get great views through the water.
Polarisers are more trouble than they are worth on a drone anyway.

Here's an example of how positioning the drone relative to the sun can eliminate glare.

Just a slight change of position and you get this:

 

[Interficiam Stercore]

I have the Skyreat CPL lens. Clips directly over the lens. You can adjust it by rotating the lens but that's about it. Seems the ghosting was on all top downs which I'm aware I can't do now if I use this lens. It unfortunate for me as I'm going to try (hopefully) get some whale shots next weekend nearby and don't want to risk taking photos where this may happen and I have to keep changing angles.

The ghosting doesn't look too bad. You could use the clone stamp tool and others to remove the artifact in post.