Mosaic Engineering, Inc.

The VAF-5D2 is an easy-to-use and effective solution to most of the aliasing and moiré problems typically encountered in 1080p video shot with the Canon 5D Mark II.  Nevertheless, it has some peculiarities and limitations of which you should be aware before deciding to purchase or use it.

Optical focus and indicated focus differ (but infinity focus is always insured).  The VAF-5D2 works well with most Canon EF lenses; lenses from 24mm to 300mm have been internally tested thus far.  However, when any optical filter (such as the VAF-5D2) is inserted between a camera's lens and its focal plane, the camera's effective optical flange focus distance is altered, and this has certain effects on the way lenses will focus with the camera.

One result of this is that when the VAF-5D2 is being used, the lens' actual optical focus distance will differ from the focus distance indicated by the lens barrel's focus adjustment ring.  The effect is most pronounced on wide angle lenses.  For example, the popular Canon 35mm f/1.4L lens, when adjusted to its minimum indicated focus distance of 12 inches, will focus at around 14.5 inches when used with the VAF-5D2.  Nevertheless, and critically, the ability to achieve focus at infinity is always assured with any lens.  (Note that with its critical focus and very shallow depth-of-field, when shooting video, filmmakers usually do not rely on the lens barrel focus indications, but instead focus the 5D Mark II with the internal or an external LCD video monitor.)

Zoom lenses can be used, but do not track focus while zooming.  Another result is that, while zoom lenses can be used with the filter, they must be considered “variable prime lenses”, since focus tracking while zooming is not possible when the VAF-5D2 filter is installed.

Cinematographer Glenn Przyborski has produced a video (http://vimeo.com/28039311) specifically demonstrating the performance of two popular Canon zoom lenses with the VAF-5D2; further details are available on our Video Resources Page.

Off-axis resolution loss for some lenses 24mm and wider.  With some lenses having a focal length of 24mm or less, The VAF-5D2 can cause a loss of resolution near the left and right edges of the image area.  The degree of this softening is aperture dependent, and varies even among differently-designed lenses of the same focal length.

For example, photographers using the VAF-5D2 have reported that the popular Canon 24-70mm f/2.8L zoom produces 1080p video that is sharply in focus over the entire field of view when used at its widest (24mm) zoom setting.  With the Canon 24mm f/1.4L prime, however, and especially at wide apertures, there can be significant softening at the left and right edges of this same field of view (though the resulting video remains quite usable in many circumstances, and the edge softening can perhaps even somewhat enhance a "shallow depth-of-field" look).

Philip Bloom has created a very objective and informative video on the VAF-5D2, which gives a quantitative impression of the performance of the filter with a wide variety of lenses, focal lengths, and apertures: http://vimeo.com/29069158.

Cinematographer Glenn Przyborski has produced a video (http://www.vimeo.com/26764997) specifically addressing the use of fixed-focal-length wide-angle lenses with the VAF-5D2; further details are available on our Video Resources Page.

Remove VAF-5D2 for still photography.  The anti-aliasing filter assembly must be removed to shoot high-quality still photography, as otherwise it will degrade the performance of the Canon 5D Mark II at its full 21MP resolution.

Aliasing in the LCD viewfinder does not indicate aliasing in the recorded 1080p video.  When using the VAF-5D2 filter, the live video image on the small, built-in LCD screen of the 5D Mark II (or on any external LCD screen) will appear to be the same as without the filter, and may show moiré and other aliasing artifacts.  These artifacts (with or without the VAF-5D2) are caused by the camera's internal downsampling algorithms that generate the viewfinder display, and as such are unrelated to aliasing artifacts (if any) in the full-resolution 1080p video being simultaneously recorded.  The low-resolution electronic viewfinder display is really only intended and adequate for framing and focusing.

Warning concerning Nikon manual lenses.  Some older Nikon manual lenses have a small lever (for automatic iris operation) which protrudes from the flange face of the lens in the direction of the focal plane.  Some users have reported that this lever can impact the VAF-5D2 when the filter is installed in the 5D Mark II, resulting in possible damage to the the filter, the lens, and/or the camera.  Therefore we recommend using extreme caution with this configuration. Note that some users have reported successfully removing this iris lever from their lenses in order to use them with the VAF-5D2.

Circular polarizers.  As is the case with most digital cameras, if a polarizer or polarizing filter is used with the VAF-5D2, it needs to be a circular polarizer, or have a circularly polarized output.

F. A. Q.  Finally, please see also this list of frequently asked questions about the VAF-5D2.