I wanted to test out the effect of the VAF filter on the video on the 5D Mark II. As you all know, the 5D2 suffers from aliasing in the full frame mode. On close up subjects it can be fine and not show at all, but on repeating patterns, clothing and fine contrasting detail it can completely ruin the video.
The hypothesis :
I think the VAF filter will eliminate the aliasing problem for full frame video. I also think that it may reduce sharpness.
Additionally, I think using a VAF filter AND crop mode will yield reduced sharpness, but I don't know to what degree.
Variables :
Canon 5D Mark II 2.1.2 w/94k actuations
Canon 35mm F/2 IS @ F/8
Canon EF-S 10-18 STM @ F/8
VAF 5D2 AA Filter
SanDisk ExtremePro 32Gb UDMA 7 160MB/s CF card
magiclantern-crop_rec-3k_Updated_Center_4.20pm-5D2-eXperimental.2019Nov14.5D2212 from Reddeercity
100 ISO
FF mode : 1866 x 1248 1.00x Crop @ 23.976 fps 1/50s
Crop mode : 2784 x 1080 2.01x Crop @ 23.98 fps 1/50s
The setup :
Using a tripod, I shot multiple different scenes using the same settings with the VAF filter and without the VAF filter. For the first scene, I tested two lenses : a 35mm and a 10-18 Ultra-wide zoom meant for EF-S. Since I have the original VAF-5D2 filter and
not the updated VAF-5D2b filter specifically designed for wide angles, I expect the performance of the VAF to be less using the 18mm focal length. Since I am using an EF-S lens on full frame, I expect the corners to be blurry and with vignetting, so I will use center crops only for comparisons. All of these shots are within 30 seconds of each other.
Here is my exposure for this test. Note the picture is at F/7, but I later changed this to F/8. The RAW zebras were only green in the sky, not green and blue like pictured.
Here are the tests. I added labels to aid in comprehension :
Click on each of these photos to see them in full size.
Initial conclusions :
Full frame video has now no aliasing when viewed at 100%. An interesting side-effect is the reduction of compression artifacts. This can be viewed clearly in the grass in both full frame tests. The reduction in sharpness is (to my eye) due to the elimination of false sharpness created by the aliasing. I most definitely think that the resulting image with the VAF filter is better when using FF.
Crop mode is straight up not usable. The sharpness reduction is dramatic. The shots look out of focus, but I can assure you I focused using the 10x liveview and autofocus on the central part of the image multiple times. I even re-did the whole test again because when I viewed the footage on the computer, I thought I made a mistake. We can conclude that using the VAF in conjunction with crop mode will yield
poor results at best.
More testing :
After this initial test, I set out to test out different scenes to see the actual difference in real world tests. Since this filter was not intended for crop mode video and just for full frame, the later tests are all tested on full frame with the 35mm F/2 IS USM.
You can make your own observations.
Here are the original files used in the test.More conclusions :
With the further testing I did, I can say with confidence that for FF video in RAW on the 5D2, the VAF filter does its job very well. It reduces aliasing and compression artifacts to almost invisible levels when viewed at 100%. Crop mode is not to be used with the VAF filter. I do not think it was designed for that so I cannot fault it in that aspect.
Hope you found my tests useful !
