Using ND filters

[dxer]

I am using this Polar Pro filter on my Typhoon H with stock lens.
The thing is that toward edges(in a circle) image/video is more darker.

Is this normal or I am doing something wrong ?

 

[Rayray]

Which ND filter number did you use and what were the brightness conditions. Got a pic?

 

[dxer]

YUN00049

Filter ND8. Look how corners are darker. It was full sunny day. Shutter speed 1/100.
I think on videos this is more pronounced, but it is visible on the image too.

 

[ricmitch]

I notic that with mine as well

 

[Rayray]

Thanks. Yep, it is perceptible. Seems to be to the left and right, but not top or bottom.
Did you compare it without the filter?

 

[dxer]

I will do the comparing in same conditions one day and see if it is different.

 

[Wingshooter]

It sounds like Vignetting and is often an unintended and undesired effect caused by lens limitations. I use the ND Polar Pro on my CGO3 4k camera and it does have some similar effects. These cameras we have are not known for their high quailty lens and coupled with a fixed aperture of f/2.8 makes their depth of field real shallow.

 

[Eagle's Eye Video]

The fixed 2.8 does have a relatively shallow depth of field, but these cameras are also fixed
focused on "infinity"... which gives a relative focus range at that f-stop of about 4-5 feet to "infinity".

The vignetting is an aberration in the lens itself... and more apparent in the wide angle lenses
used on the CGO cameras... the filter will not increase that unless the filter is poorly designed
(which I do not believe is the case with the PolarPro filters).

BTW, as mentioned on another thread, the Polar Pro's are on sale right now at Best Buy for $14.99
for the 3 pack of 4x, 8x and 16x.

 

[PatR]

Perhaps because the filters are so much larger than the lens itself they are creating a shadow? I've experienced this frequently with my Polar Pros as well, along with light "blooming" at the upper middle of still photos when using Polar Pro ND4 filters. The blooming may be light leaking around the top of the filter mount when mounted on the camera but that doesn't make much sense when considering the vignetting. For the most part I've stopped using ND filters and now shoot stills in both DNG and JPG formats to take advantage of the massive increase in data contained in the DNG's for more post processing latitude. If the JPG looks great I'll use them as is but if not I fall back on the DNG and work with it.

 

[Ty Pilot]

When speaking of cameras like the CG03+ or GoPro or similar, these cameras have a very deep depth of field, not a shallow depth of field. A shallow depth of field would be when a cameras' focus is just a few inches or feet at a given distance, and all else is out of focus, whereas our cameras basically have all items in focus from a few feet to infinity. I also agree if you are shooting stills, do not use an ND filter and work with the DNG's for maximum image quality.

 

[Eagle's Eye Video]

Depth or shallowness of depth of field is tied directly to the f-stop of the lens used, but that range of focus is also
tied to where the focus of the lens is placed. By being a fixed focus distance of "infinity", you get the maximum
range of focus, for that specific aperture setting. If the H used a fixed f-stop of 4.0, that would effectively create
a "deeper" depth of field... and a closer near distance focus. But as correctly pointed out, the ND filters should
only be used to correct video artifacts...

 

[Michael Brown]

I've never used ND filters on my H. I do not want to alter my depth of field.

 

[Eagle's Eye Video]

I've never used ND filters on my H. I do not want to alter my depth of field.

Using ND filters on a fixed aperture camera like the CGO series will not alter your depth of field.
It is the shutter speed that is changed to compensate for the exposure difference. This is primarily
used to slow the effective shutter speed to eliminate "prop flicker" in video footage.

 

[Rubik]

I use the ND filters to eliminate the staccato effect of high shutter speeds when there is motion in the video on a bright day. With the ND16 filter, I can shoot at 1/60th of a second, which is supposed to be "ideal" for 30 fps video. I shoot 4k video almost exclusively. If I need a still, a pretty descent frame can be extracted from the video. For me, it doesn't make sense to land and remove the ND filter and take off again for a still shot. But that's just me.

I've also seen a bit of darkening around the edges of images with the PolarPro filters. To tell the truth, though, it didn't bother me until you mentioned it. Since I have not compared images with and without the filter, I can't say if the filter is at fault or not.

I've never been happy with my DNG stills. Too much color granulation when zoomed in. Would someone please post a good raw DNG image here so I can compare with mine? Thanks.

 

[Eagle's Eye Video]

I know what you are talking about Rubik... particularly in the shadows... unfortunately that is not
an artifact of the lens. In my opinion, that is caused by the fact that the CGO series of cameras
do not have a particularly good dynamic range. Going to the 1 inch sensor in the Pro will really
reduce that. The fact is, you are seeing more of it since installing the PixAero, because the lens
is sharper.

 

[Rubik]

View attachment 6219

I know what you are talking about Rubik... particularly in the shadows... unfortunately that is not
an artifact of the lens. In my opinion, that is caused by the fact that the CGO series of cameras
do not have a particularly good dynamic range. Going to the 1 inch sensor in the Pro will really
reduce that. The fact is, you are seeing more of it since installing the PixAero, because the lens
is sharper.

I don't have the PixAero lens. I'm not unhappy with the sharpness of my stock lens.
If Yuneec provides an upgraded camera with 1" sensor, we should see improved dynamic range.

 

[PatR]

Considering they've been running with Sony sensors, if they continue that path we should end up pretty happy. That pic almost looks like a mountain of amethyst.