Mosaic VAF filter worthless?

[Casey Danielson]

You're shooting DSLR video and you have to choose between either:

- Shooting RAW video with no anti-aliasing.

or

- Shooting h.264 with an anti-aliasing filter.

In other words, how helpful is a VAF filter when you're recording h.264 video instead of RAW?
VAF filters attack moire/aliasing, but don't do much to prevent h.264 compression artifacts. If RAW was not an option, and one were limited to recording h.264, how much does an anti-aliasing filter really help?

[Seth Bloombaum]

Originally Posted by Casey Danielson

...VAF filters attack moire/aliasing, but don't do much to prevent h.264 compression artifacts...

OK, I don't own the M2, M3, or Mosaic VAF filter. Though I do use the M2...

However, you're asking a pretty open question.

My question back to you is, at a practical level, have you ever experienced objectionable h.264 compression artifacts from an EOS camera like the 5Dm2 or 3?

Evaluating these kinds of features & functions at a distance is really hard! To me, the real questions revolve around how good is good enough? Because "only the best specs will do" logic doesn't really help make purchase decisions.

I find it remarkable that the Magic Lantern project is moving towards MLV Raw acquisition, and the latest tests from Mr. Ramasola are stunning.

But, I have to take all that with a grain of salt, too, knowing that the workflow will be demanding of time and processing power... and also be honest with myself that I'm not working on any projects currently where I or clients would find typical camera h.264 compression objectionable.

I do a fair amount of greenscreen work, and have had pretty good results even on dSLR native recording, which would be a weak area of h.264 encoding... But set up and lit right it works with modern keyers.

Sorry I don't have the practical experience you're looking for, but when you do get it, it's likely that your experience of the tools and your evaluation of the quality will be different!

[Ted Ramasola]

VAF is necessary, in both raw and h264 IF you don't want aliasing and moire in tight repeating patterns.

Not needed if you shoot crop mode all the time.

Don't think that raw removes aliasing and moire, in fact 14 bit makes the line skipping more obvious. Since crop mode is 1:1 pixel recording, using vaf in this mode in fact softens the image.

VAF is not needed when using 5dmkIII.

[Shayok Mukhopadhyay]

AVF helps avoid moire, doesn't completely eliminate it. I have one for my 5d2, I've tested it against real world problematic targets (like the grill on my air-conditioner). One annoying thing is that it throws off the focus if you zoom in or out.

[Casey Danielson]

Originally Posted by Shayok Mukhopadhyay

...it throws off the focus if you zoom in or out.

1) Do you mean when zooming in or out during a shot? Or are you saying it is always soft at either end of the zoom range?

--- ---

2) Here is how the rep at Mosaic responded to my question about using a VAF when shooting h.264 :

Hi Casey--

Thanks for writing. Yes, definitely: When we initially developed the VAF-6D, h.264 recording was the only available option on the 6D, and so this was actually the filter's intended purpose. It's extremely effective for 6.264 video; our own initial demo video was shot this way -

VAF-6D & Canon 6D - Initial Demo Video on Vimeo

in case you haven't found it.

As a secondary benefit that may not be obvious, the filter actually improves the performance of camera's h.264 encoder also: The removal of the false high-frequency details (aliasing artifacts) means that the encoder doesn't have to compress them, so more bandwidth bits end up being allocated to rendering the actual video image with better fidelity.

Anyway, I hope this helps! Please let us know if you have any further questions;

Thanks in any case for your interest in our filters;

Regards--

Mosaic Optoelectronics, Inc.
210 W. Hamilton Ave. #290
State College, PA, 16801, USA
(+01) 814-359-6290
cubanski@mosaicengineering.com
Mosaic Engineering Home

[Ted Ramasola]

The VAF filter changes the focusing distances on your lenses so you have to confirm focusing by eye. The markings on the lens barrel will no longer be applicable and also the MOD of your lenses will be longer.

You can't change zoom settings and maintain focus, but most stills are like this also.

Just note that if you shoot stills, to remove the filter as it softens it. also when using magic lantern in crop mode.

[Juha Nurminen]

I am using Canon 60D and shooting video solely in 1280x720@50. Would the Mosaic VAF filter help in 720p mode, or is it designed only for 1080p shooting?