TELE mode airplanes and more 14-140mm + Hoya High Density polarizer
- Thread starter hazna
- Start date
Jonathan12uiz
Well-known member
isn't what you are calling 'onion layers' an example of aliasing? correct me if i'm wrong, but the polorizer might not be causing it, it is just amplifying the aliasing in the sky.
someone correct me if I'm totally off.
someone correct me if I'm totally off.
Matthew P
Well-known member
You're a bit off.
These 'onion layers', are the result of codec posterization, and nothing do do with aliasing.Hazna, the poleriser also has nothing to do with this effect, it is merely a compression method. Are the 'onion layers' present on the original MTS files? If not, then you need to render to a better codec.
Barry_Green
Moderator
Yeah, the "onion layers" (great name, btw) is actually posterization, which has also been called "banding" on gradients. The polarizer isn't causing them, but may be causing the system to exaggerate the appearance of them. Polarizers can darken a blue sky, depending on what angle they are from the sun. That first clip of the plane is a great demonstration, because it starts out with a pale blue sky, then as he tracks with the plane it gets darker and darker, then when he passes the mark of most polarization the sky gets lighter and lighter until it's that pale blue again.
If the sky was completely pale the whole time, there would be less of a gradient and therefore less posterization happening. But because the polarizer darkens the sky, you see a more noticeable gradient.
This shouldn't be visible in the source footage (or be barely visible) unless you're using an unhacked GH1; an unhacked GH1 would probably show it. Issues like this normally come about from exporting to a too-highly-compressed codec on output, or added by vimeo's recompression.
If the sky was completely pale the whole time, there would be less of a gradient and therefore less posterization happening. But because the polarizer darkens the sky, you see a more noticeable gradient.
This shouldn't be visible in the source footage (or be barely visible) unless you're using an unhacked GH1; an unhacked GH1 would probably show it. Issues like this normally come about from exporting to a too-highly-compressed codec on output, or added by vimeo's recompression.
Yes it is the codec but the circular polarizer is to blame.
Especially when going wider. It is a known "defect/affect" to darken certain part a lot more.
I ordered a linear Tiffen polarizer. I hope it will work better then the circular in that aspect.
If not... will just use ND filters.
Especially when going wider. It is a known "defect/affect" to darken certain part a lot more.
I ordered a linear Tiffen polarizer. I hope it will work better then the circular in that aspect.
If not... will just use ND filters.