5DS vs 5DS R Accutance, Resolution, and Artifact Comparison.

   Canon's new high resolution cameras, the 5DS/R have reignited the debate over the virtues and cost of having an optical low pass filter (OLPF).  Thus far the posted samples appear to show a clear sharpness and resolution advantage for the R version.  I have been wondering how much of this apparent advantage is real resolution and how much is simply a difference in accutance that can be corrected for in post processing.  With DPreview posting studio samples from the cameras, there is now a high quality comparison available.  I have opened the raw files directly into Lightroom and only adjusted the sharpening as specified below.

   The first images are the raw files loaded directly into Lightroom with the default sharpening setting of Amount = 25.  The crop from the studio scene has been chosen deliberately to emphasize both resolution and color artifacts.  Neither effect should be as strong in most real-world images.  Clearly the SR version has higher accutance and displays stronger color artifacts as expected.  Interestingly, the S version isn't completely artifact free implying that the OLPF isn't strong enough to completely eliminate aliasing.

Left: 5DS Sharpening = 25.  Right:  5DS R Sharpening = 25.

   The second set of images has a bit of sharpening applied to the S version.  Clearly a little sharpening goes a long way and increases the accutance and thus the apparent sharpness significantly above the SR version.

Left: 5DS Sharpening = 50.  Right:  5DS R Sharpening = 25.

    In this third set of images, has equal sharpening applied to both images.  The SR again leads in accutance but has become over-sharpened.  To come back to an appropriate level for a print, the sharpening needs to be backed off.

Left: 5DS Sharpening = 50.  Right:  5DS R Sharpening = 50.

   This final set of images has the sharpening set such that the accutance looks roughly equal to my eye.  Unfortunately this is rather subjective.

Left: 5DS Sharpening = 50.  Right:  5DS R Sharpening = 35.

The differences between the two images are now pretty subtle.  Upon close inspection there are some apparent details that are clearly visible in the SR version that do not show up as well or as clearly in the S version.  The SR also shows stronger color artifacts, as expected.  In the end the difference between the cameras is splitting hairs.  The S version seems to tolerate sharpening better, but also needs a bit more of it.

Personally, I am willing to give up a slight amount of detail in exchange for not having to deal with as much aliasing or as many color artifacts.  As has been demonstrated by the popularity of AA-less cameras over the last several years, others may find the SR version better for their needs.