VENICE .ART files

[videosoul]

Can anyone explain to me exactly what ART files are and how they differ to LUTs please?

I've obviously read the marketing material, but I've never used the ART workflow myself, and am curious to know more. What specifically are they, and why exactly are they better?

Thanks!

[alisterchapman]

To make 3D LUT's a manageable size 3D LUT's don't have an adjustment for every possible input and output value, if they did they would be massive. So, 3D LUT's divide the image into ranges, typically 33x Red 33x Green 33x Blue. Each of the 33x segments has the same correction value, so within an image there will be 33 steps between each correction. These steps can often show up within the output image as banding or odd sudden colour/brightness shifts. To prevent these steps in post production additional calculations are used to smooth out the steps by interpolating between each of the ranges within the LUT, but this needs a lot of processing power to do well. Especially if you not only interpolate within each colour input channel but also 3 dimensionally across all 3 output colours. In a camera there often isn't sufficient processing power to perform these interpolation processes so banding is seen on the cameras output.

 

The .art system was designed as an alternative to 3D LUTs for the original Venice camera so that you get a  transformation function similar to a 3D LUT but without introducing the commonly seen step/banding artefacts that were a result of the limited amount of interpolation available in the original Venice camera. In Venice 2 the LUT processing capabilities have been greatly improved so that normal 3D LUTs now have much better interpolation and banding is rare.

[videosoul]

To make 3D LUT's a manageable size 3D LUT's don't have an adjustment for every possible input and output value, if they did they would be massive. So, 3D LUT's divide the image into ranges, typically 33x Red 33x Green 33x Blue. Each of the 33x segments has the same correction value, so within an image there will be 33 steps between each correction. These steps can often show up within the output image as banding or odd sudden colour/brightness shifts. To prevent these steps in post production additional calculations are used to smooth out the steps by interpolating between each of the ranges within the LUT, but this needs a lot of processing power to do well. Especially if you not only interpolate within each colour input channel but also 3 dimensionally across all 3 output colours. In a camera there often isn't sufficient processing power to perform these interpolation processes so banding is seen on the cameras output.

The .art system was designed as an alternative to 3D LUTs for the original Venice camera so that you get a  transformation function similar to a 3D LUT but without introducing the commonly seen step/banding artefacts that were a result of the limited amount of interpolation available in the original Venice camera. In Venice 2 the LUT processing capabilities have been greatly improved so that normal 3D LUTs now have much better interpolation and banding is rare.

Good info, thanks!

So are the .art files more like 65x65x65 LUTs? And so are .art files now somewhat redundant in the Venice 2 then?