I've posted this thread on another website, but thought I'd have better luck getting a response here on a specialist video website.
I have a Sony NEX-6 and I think it does great video, but it is marred by moire/aliasing artifacts and I'm interested in looking at ways this can be reduced.
As I understand it, moire/aliasing is caused because each high resolution frame of video is not properly downsampled to 1080p as the processing required to do this would be too much at 25/50 fps (PAL) or 30/60 fps (NTSC). Instead, lines are just skipped, so in areas where there are hard lines or fine patterns these artifacts can appear.
Solutions to help reduce moire/aliasing (other than purchasing a dedicated camcorder!) seem to revolve around softening/blurring the image that reaches the sensor - enough to reduce the moirse/aliasing effect but not so much that it effects the sharpness of the final 1080p video significantly.
The first suggestion I saw was to turn sharpness down to -3 in whatever Creative Style you are shooting in. I found though that this didn't seem to be enough to make a noticeable difference for me.
The other thing that a lot of people seem to be trying to reduce moire/aliasing is various filters on the lens of the camera. I am interested in trying this, but I was wondering if anyone had tried anything similar and what results they had.
I was thinking of trying a simple diffusion filter, but here is an interesting video of what can be achieved with a simple eyeglass lens:
www.youtube.com/watch?v=xIVMvCDOt54
Caprock do a set of filters:
http://caprockdev.com/antimoire.htm
This video demonstrates a solution (available for certain DSLR's) that involves a filter going behind the lens. It's not available for NEX, but does show the possibilities:
http://www.youtube.com/watch?v=pUXEm6sD8oM
Make sure you view the videos at their highest resolution to properly see the effect.
Any thoughts/advice on what might be worth trying?
I have a Sony NEX-6 and I think it does great video, but it is marred by moire/aliasing artifacts and I'm interested in looking at ways this can be reduced.
As I understand it, moire/aliasing is caused because each high resolution frame of video is not properly downsampled to 1080p as the processing required to do this would be too much at 25/50 fps (PAL) or 30/60 fps (NTSC). Instead, lines are just skipped, so in areas where there are hard lines or fine patterns these artifacts can appear.
Solutions to help reduce moire/aliasing (other than purchasing a dedicated camcorder!) seem to revolve around softening/blurring the image that reaches the sensor - enough to reduce the moirse/aliasing effect but not so much that it effects the sharpness of the final 1080p video significantly.
The first suggestion I saw was to turn sharpness down to -3 in whatever Creative Style you are shooting in. I found though that this didn't seem to be enough to make a noticeable difference for me.
The other thing that a lot of people seem to be trying to reduce moire/aliasing is various filters on the lens of the camera. I am interested in trying this, but I was wondering if anyone had tried anything similar and what results they had.
I was thinking of trying a simple diffusion filter, but here is an interesting video of what can be achieved with a simple eyeglass lens:
www.youtube.com/watch?v=xIVMvCDOt54
Caprock do a set of filters:
http://caprockdev.com/antimoire.htm
This video demonstrates a solution (available for certain DSLR's) that involves a filter going behind the lens. It's not available for NEX, but does show the possibilities:
http://www.youtube.com/watch?v=pUXEm6sD8oM
Make sure you view the videos at their highest resolution to properly see the effect.
Any thoughts/advice on what might be worth trying?