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Author Topic: Anyone using the VAF Anti Aliasing filter?  (Read 1770 times)

syrcular

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Anyone using the VAF Anti Aliasing filter?
« on: November 17, 2013, 12:02:30 AM »
Hi all,

Is anyone out there using the VAF Antlaliasing filter for any of the canon bodies and can tell me how their experiences have been?  I'm in the middle of a purchase decision, and thinking about buying a 70D as my second stills and video body to my Canon 5D Mark II.  I really like the 70D's speed of focus and the video autofocus system, but when I shot with it the other day for video I was so disappointed by the amount of moire and aliasing I experienced.
Just curious..if anyone's used the filter and had good or bad experiences?

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Anyone using the VAF Anti Aliasing filter?
« on: November 17, 2013, 12:02:30 AM »

Mt Spokane Photography

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Re: Anyone using the VAF Anti Aliasing filter?
« Reply #1 on: November 17, 2013, 01:18:01 PM »
You do realize that they work by reducing resolution.  You get a much reduced resolution due to smeared details.  That's why AA filters are weak, its a fine line to walk between high resolution and Moire.  The theory is that it doesn't matter for video.
 
Also note that the 70D is able to autofocus during video.  I don't believe that is going to work with one of these.
 
They don't list one for the 70D in any event.
 
 

syrcular

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Re: Anyone using the VAF Anti Aliasing filter?
« Reply #2 on: November 17, 2013, 02:47:13 PM »
Well...that's not entirely accurate.  And yes...this filter would not be in the camera during photography.  It's meant for use only in video mode.
You should check out this review:  http://www.eoshd.com/content/7120/canon-5d-mark-ii-mosaic-engineering-vaf-5d2-anti-aliasing-filter-review

Also...there is one for the 70D:  https://vimeo.com/76922520 and it also indicated that it does not effect the 70D autofocus system in the description.

Thanks for your 2 cents though.  :)


Mt Spokane Photography

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Re: Anyone using the VAF Anti Aliasing filter?
« Reply #3 on: November 17, 2013, 08:11:22 PM »
Well...that's not entirely accurate.  And yes...this filter would not be in the camera during photography.  It's meant for use only in video mode.
You should check out this review:  http://www.eoshd.com/content/7120/canon-5d-mark-ii-mosaic-engineering-vaf-5d2-anti-aliasing-filter-review

Also...there is one for the 70D:  https://vimeo.com/76922520 and it also indicated that it does not effect the 70D autofocus system in the description.

Thanks for your 2 cents though.  :)

I got the impression on the VAF site that there are things that cause focus issues
http://www.mosaicengineering.com/products/vaf/faq.html
 
They have added the 70D since I looked at the site earlier.  I looks less klutzy than some of their models.  They claim it does not affect resolution, but the basic premise of a AA filter is to reduce or Blur the resolution.  They are also referred to as lowpass filters or Blur Filters.  They filter out the high frequencies and fine detail with it.
 
The premise is that you won't miss the fine detail in a video.  As I said, its a fine line, if you go beyond the Nyquist limit, you are not gaining anything but if you cut too much, you lose detail.  The Camera makers usually err on the side of cutting too much detail for stills, and letting too much thru for video.
 
There is no such thing as a perfect filter.  It is often a combination of a optical AA filter plus a bandpass filter in the signal processing. 
 
Here is some more info.
http://en.wikipedia.org/wiki/Anti-aliasing_filter
 

paul13walnut5

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Re: Anyone using the VAF Anti Aliasing filter?
« Reply #4 on: November 18, 2013, 12:15:13 PM »
Not using.  Seemed an expensive fix for something that I can largely deal with in post.

My feeling was that you can to some degree remove moire, you can't put back in what an aggressive AA filter has taken out, without sharpening, which in itself can be horrific.

I shoot with sharpness 1 notch below middle.
I put a .5px gaussian blur over video layers as a matter of course.
I ensure the field order is set to progressive from my APR transcodes, to my timeline to my output format or disc encoding settings.

I can recall two occassions where moire was very intrustive, and on those occassions I used a second layer with heavy Marvels filter on it and unaffected areas revealed using garbage mattes

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Re: Anyone using the VAF Anti Aliasing filter?
« Reply #4 on: November 18, 2013, 12:15:13 PM »