VIEWFINDER
App Store

A LUT or curves file will not import

The Looks panel says why in a banner. The usual causes are a 1D LUT, a cube with more than 128 points a side, a file that is not text, or a Photoshop curves file from a version the app cannot read.

Viewfinder reads a 3D .cube, a Photoshop .acv curves file, or a LUT saved as a 512×512 image. Each message below is the banner's own words.

.cube files

  • This is a 1D LUT (LUT_1D_SIZE). Only 3D cubes can be applied to the viewfinder. Export a 3D cube from your grading app instead.
  • LUT_3D_SIZE ... is outside the supported range. The cube is larger than 128 points a side, or smaller than 2. Export it at 64 points a side or fewer.
  • The table has ... entries; LUT_3D_SIZE requires ... The file was cut short. Copy it again from the source.
  • No LUT_3D_SIZE was declared before the table started, or declares LUT_3D_SIZE more than once. The file's header is malformed.
  • DOMAIN_MIN must be below DOMAIN_MAX on every channel. The domain lines are reversed.
  • Line ... is not a keyword or an RGB triple. A stray line sits in the table; the banner quotes it.
  • The file is not text, so it is not a .cube LUT. It may be a different format renamed to .cube.

Image LUTs

  • ... is not a LUT image. Expected a HALD or tiled LUT such as 512×512. The picture has the wrong size.
  • The file could not be decoded as an image. The image is damaged or in a format the device cannot open.

Photoshop curves

  • Curves file version ... is not one this app can read (1, 2 and 4 are). Save the curves again from Photoshop.
  • ... It is truncated or is not a Photoshop .acv. The file is cut short, or it is another kind of file.
  • A curve with the wrong number of points, points out of order, or a value outside 0 to 255 is refused, with the curve and the point named.

If that didn't work

... could not be loaded: its file is missing means a LUT a look uses was deleted. Import it again and re-save the look. If a file opens in your grading app and still will not import, send it to us at [email protected] with the banner's words.

Related

Grade the picture with looks and LUTs

Updated November 2, 2026