Luts - do they sharpen footage or just change colors?

[Steve Bleasdale]

Sorry Hacob made a mistake, i created my own luts but added sharpness later on in prem pro cs6 then saved it as a preset so it does not look like you can add sharpness to a lut. they are right. Steve

[Seth Bloombaum]

Seems like the terminology misunderstandings have been straightened out...

The reason these misunderstandings occur, IMO, is that although strictly speaking a LUT has only to do with color/luma values, workflows that use log footage and application of a LUT commonly address sharpness too, not just color.

Strictly speaking, a LUT is a look-up table that reassigns the color/luma/gamma values in log footage to colors will be acceptable starting points for color correction or grading for display. Commonly, we want to use it for two reasons; we think the scene's dynamic range is too wide for conventional recording, resulting in crushed blacks, blown whites, or both, and/or, we want to preserve more choices in post. The downside is that you (almost) always *must* apply effects/LUTs in post. It's more of a cinematography approach, not a common videography method.

Sharpness is an independent effect that is better addressed in post as well, if that fits in your workflow. Some cameras will reduce the in-camera processing for sharpness when you apply a log preset, some won't. It's perhaps worse than color, in that the in-camera processing choices for sharpness become baked in to your footage. They really *can't* be properly evaluated in the field, you need good monitoring that you're not going to get with most camera's LCD or viewfinder.

Not only that, but in-camera sharpness is a single setting in many cameras. Post sharpness, depending on the effect chosen, may allow for degree of sharpness, but also the fineness of detail to which the effect is applied, and, the edge-contrast values to which the effect is applied.

A good videographer will have seen so much of their camera's footage under different circumstances that they'll be able to choose in-camera settings that won't require any post color or sharpness work.

A good cinematographer may have a larger reference monitor available during the shoot, but will still dial down sharpness, leaving the decisions to a post-production grading process.

Here's a good reference:
Guide to Image Sharpening

Too much sharpness looks like old TV tech... not like film, not like what we expect from modern electronic cinematography gear and methods.

[Steven Digges]

Seth, Thank you, for yet another in depth, accurate, and informative response to a topic.

The sound of Gary wielding his ruler on someones knuckles like a 90 year old Nun teaching cursive in the fifty's is so old!

Kind Regards,

Steve