Hi,

i got the Frewell Bright Day ND-Filter package today. However I have some weird glare in a lot of pictures when using them. It doesn't really matter which filter of the 4 I use, except if I don't use any of them, the problem goes away.

It looks like this (check the left and right corner):
https://imgur.com/a/psMFYoe

Does anyone have an idea what causes this issue? Is this normal and maybe I'm doing something wrong?

1.  The bright spots i the corners of your photo aren't what's usually called flare.

2.  I don't use any of them, the problem goes away.
Simple .. If you don't like bright corners, don't use those filters.

3.  Why are you using ND filters for still photography with your drone?
The only reason to use ND filters for drone still photography is to force a slower shutter speed.
Unless that's what you want to do, leave the ND filters off as they don't do anything to make your images better.

If your using Sunnylife ND filters they produce vignettes in the corner of the picture, ok in video as the image is cropped.  

Labroides Posted at 5-8 16:44
1.  The bright spots i the corners of your photo aren't what's usually called flare.

2.  I don't use any of them, the problem goes away.

Hi,

I know this isn't flare but it kinda looks like it. Obviously I don't use the filters to just take photos, but very often I take a few in between videos.

I also have these bright spots in videos. It is significantly less due to 16:9, but it's still there if you take a closer look.
As TDZHDTV pointed out the effect gets worse when a 4:3 photo is taken, makes total sense.

I just reached out to Freewell what I can do about this ... and additionally ordered PGYTECH filters which seem to have a different approach.

TDZHDTV Posted at 5-9 00:15
If your using Sunnylife ND filters they produce vignettes in the corner of the picture, ok in video as the image is cropped.

This is why I use Sunnylife more often.

I had this white flare in the right bottom corner only once, while taking a picture having the bright sun left in front of me. As I crop all my photos in post to 16:9, I got rid
of the flare. All other photos were perfect.
Next time, I will test my cheap Sunnylife sun-cover/gimbal protector.

You can often put this down to using filters and they all have some quirks.

Hi,

thanks for the replies. As stated before, I will now try these filters:
https://www.pgytech.com/collections/for-mavic-mini/products/pgytech-mavic-mini-filter-professional?variant=31073460322397

These are not polarised and in a different shape which will hopefully fix the reflections which seem to be in a radial shape.
However I already read that the gimbal might have issues due to the weight of these filters ...

UweE Posted at 5-9 03:19
I had this white flare in the right bottom corner only once, while taking a picture having the bright sun left in front of me. As I crop all my photos in post to 16:9, I got rid
of the flare. All other photos were perfect.
Next time, I will test my cheap Sunnylife sun-cover/gimbal protector.

Yes I can confirm the effect seems to get worse, the more light the drone is exposed to. This makes me believe that it is some sort of reflection thing going on.

I made a little test and can confirm!

with a simple gimbal-hood, the flare is gone, but that's not the solution

Did you use PL Filter for testing?
I have the theory That the non PL just work fine since they dont have the circular Shape.

yes the PL filter!

Just a quick update: I received the PGYTECH filters today and I can say they do not have this issue. This proves me right, that it in fact the underlying issue might be the circular shape of the Frewell FIlters. In fact I don't have any issues with the PGYTECH filters. The gimbal works fine.
However the build quality seems inferior to the Frewell filters. The mounting bracket seems a little fragile, while the Frewell is rock solid. But maybe this has been done to reduce the weight of the filters.

As soon as the weather gets better I will extensively test the new filters and post another update.

I have the same problem with these filters...also when filming away from the light...the it gets pretty dark in the bottom left and right...gives it a distorted look to it...

Flaring (with a reddish hue) also happens without filters.

El Diabolico Posted at 7-17 22:01
Flaring (with a reddish hue) also happens without filters.

That (at least for me) is not true.

djiuser_ZutghNDTLB2U Posted at 7-18 03:39
That (at least for me) is not true.

At a specific angle, the lens flares. This has already being discussed here previously.

By the way, I can’t open your link but from your description it seems that what you’re seeing isn’t flare but a reflection from the polarized filter ring... those aren’t the same.

Labroides Posted at 2020-5-8 16:44
1.  The bright spots i the corners of your photo aren't what's usually called flare.

2.  I don't use any of them, the problem goes away.

That's not so much right what you say:

ND filters should not give "bright" corners. Absolutely not. They are not invented for this purpose, so it's not normal having those veils in the corners

ND filters are usefull not only for a slower shutter speed, but they slightly increase the sharpness of pictures / videos. Also the colors are a little bit corrected.
I know that these differences are minimal, but a trained eye can notice them, trust me.

MicheleFerrante Posted at 8-26 08:57
That's not so much right what you say:

ND filters should not give "bright" corners. Absolutely not. They are not invented for this purpose, so it's not normal having those veils in the corners

That's not so much right what you say:
What I said is correct.

ND filters should not give "bright" corners. Absolutely not. They are not invented for this purpose, so it's not normal having those veils in the corners
It's not normal, but it's not flare.
Flare is internal reflection inside the lens.

ND filters are usefull not only for a slower shutter speed, but they slightly increase the sharpness of pictures / videos. Also the colors are a little bit corrected.
I know that these differences are minimal, but a trained eye can notice them, trust me.
No ... I won't trust you on that, because it's just not true.
Increasing sharpness ?? !!!
Correcting colours ??  !!!
ND filters don't do either of those things.

Labroides Posted at 8-26 13:30
That's not so much right what you say:
What I said is correct.

In some cases they do it. Even if "imperceptibly". You must just have a trained eye a little bit to notice that. Obviously I don't mean so much corrected colours that you don't need post production. Of course not. But as I said, in some cases they do it even if almost imperceptibly

"ND filters are usefull not only for a slower shutter speed, but they slightly increase the sharpness of pictures / videos. Also the colors are a little bit corrected."
No, this is not true. ND-filters (or any other filter) can of course not increase sharpness. They actually will reduce sharpness slightly unless they are made of very high quality glass.
As for colours, ND-filters  can add a colour tint because they rarely are "neutral", and the denser the filter, the more colour shift may appear, often magenta.  ND-filters do not correct any colour, of course.

"I know that these differences are minimal, but a trained eye can notice them, trust me.""
As a pro photographer for several years, I have what you call a "trained eye", and I know you are wrong.