What bands does your input image contain? From your veg indices result it appears that you only have red & nir wavelengths available. Josh

It is a 6 band image of Landsat. It has all bands. I opened a Landsat file with open external / geotiff with metadata command.

The Vegetation indices supported by the VI calculator are primarily used on hyperspectral images that have the narrow band definitions required for the VI. Landsat has only 6 wide bands which can be used for NDVI and a simple ratio but not for the more specific VIs. A list of the VIs are in the ENVI Help and can also be found in our Documentation Center: http://www.exelisvis.com/docs/vegetat... ENVI 5.2 will have an expanded list of vegetation indies that you might find useful and can be used with a variety of multispectral sensors.