introducing luttie 2.0 — a new grading engine

luttie's grading engine has been rebuilt. this post covers what changed, what didn't, and why any of it matters to your grades.

if you read the post about this back in august, this is that work landing.

the chain is no longer fixed

before, luttie applied your grade as one fixed sequence. white balance, then exposure, then contrast, then the wheels, then the lut, then curves, and so on — welded in that order, with no way to change it.

that sequence is now ten separate stages you can rearrange:

white balance · exposure & contrast · color wheels · tone · saturation · lut · hsl secondary · curves · vignette · film effects

move curves ahead of your lut and the image genuinely changes, because a lut is a fixed colour-to-colour map and what you feed it matters. some pairs make no difference at all, which is worth knowing before you spend time experimenting.

a node graph, with a preview on every stage

switching on advanced mode adds a node graph under the image. it shows the chain as connected nodes, and each one carries a thumbnail of the picture as it leaves that stage — so reading left to right shows your grade being assembled rather than only its end result.

you can drag a node to move it in the chain, and switch any stage off with its power button without losing its settings. bypassing a stage to see what it was contributing is the single most useful habit the node workflow teaches.

full walkthrough here, and if nodes are new to you, an explanation of the idea.

16-bit float processing

this one applies to everyone, whether or not you ever open the node view.

previously each step handed its result to the next at 8 bits per channel. that is fine for a short chain, but every step rounds its output, and stacking a dozen of them shows up as banding in skies and gradients. the new engine keeps everything in 16-bit float until the final write.

nothing about the colour maths changed — the same formulas, the same constants, tuned the same way — so your existing looks are the looks you already had. what changed is how much precision survives between the steps.

one engine everywhere

worth mentioning because it fixes two real bugs.

the preview, the image export, the video export and the .cube lut baker now all run the same code. previously the preview and the exporters were separate implementations of the same maths that had to be kept in step by hand.

that consolidation caught two things:

• lut export was baking grain into the colour table. grain varies per pixel position, so writing it into a lut produces random colour error rather than grain. it is now excluded, which it always should have been.
• bloom and halation do bake, and now do. both are calculated from a pixel's own brightness, which makes them representable in a lut — unlike the vignette or grain. the full explanation of what a lut can and cannot hold is here.

your reordered, partly bypassed chain exports exactly as it previews. there is no second order to keep in sync.

what has not changed

the editor you already use is untouched. the sliders, the wheels, the curves, the preset browser — same place, same behaviour. advanced mode is off by default, and if you never switch it on you will not notice anything different except slightly cleaner gradients.

existing grades render identically. a grade saved before 2.0 carries no stage order, which means it runs in the same fixed sequence the old engine used. saved projects, presets and shared links all keep working.

and the editor stays free to use. lut export is still the pro feature it was.

what is next

the chain is serial today — one stage feeding the next. parallel branches, layer mixing and positional masks are the direction, and those are what would make it a full graph rather than a chain.

if there is something you have tried to do in luttie and couldn't, that is genuinely the most useful thing you can send me. my dms on x are open.