Resolution is not Sharpness
- March 30, 2018
- Shane Hurlbut, ASC
One of the comments I hear all too often is, “4K is too sharp, it’s too much resolution.” Well, here’s the thing… resolution and sharpness are not a 1:1. Instead of thinking of higher resolution images as “sharper,” try thinking of them as smoother.
Resolution and sharpness are two different beasts.
Sharpness can be subjective and the perception of sharpness is influenced by a handful of factors like aperture, depth of field, shutter speed, lens resolution, and camera sensors. It has a lot to do with contrast too, especially along the edges of objects in a frame. For instance, by enhancing the contrast along edges in an image, a lower resolution image can actually appear “sharper” than a higher resolution image.
It’s easiest to see this in black and white so check out this image below.
Notice how the top image seems sharpest, while the other two are actually higher resolution and…smoother? Higher resolution actually helps fine detail appear smoother.
This edge enhancement thing is something that Sony and Panasonic do in many of their cameras to make their inferior sensors look “sharper,” but I think it looks terrible. One of the reasons I love RED cameras so much is their ability to tweak and customize. The image processing is all up to me, not some guy in a lab across the ocean that’s never been on a film set before.
So my point, to state it clearly, is that resolution is NOT sharpness.
Resolution helps to make images smoother.
But I don’t want you to take my word for it. I want you to hear it from some people that have been in the high resolution post-production game from the beginning: Light Iron
Light Iron has not only blazed the trail for file-based capture and management, they’re an active educator – participating in panels, writing articles, helping to teach classes like REDucation, creating webinars, and writing some very insightful blog posts. Hurlbut Visuals was lucky enough to host one of those panels.
While at Camerimage 2017, Michael Cioni, Dan Sasaki, and Ian Vertovec showed off a presentation to help dispel all those nasty myths about resolution, and how the pursuit of cinematic smoothness actually goes hand in hand with the race for resolution.
With all this said, the best camera is the camera at your disposal. Not every story requires dozens of megapixels and frame rates in the triple digits, but it’s good to know the ins and outs of the tools available to you.