I am using Landsat 8 C2L2 and I would like to compose Bands 1-6. If I don't apply the scale factor at all, what would be the problem? Also, when I am trying to find, for instance, NDVI value after I have applied a scaling factor to bands 4, 5, my new band'5 value is -0.10 to 1.34 and band's 4 is -0.17 to 1.37. Then, I try to compute NDVI using new bands' values and I get a NDVI range of -1348.38 to 1326.38. On the other hand, when I calculate NDVI without using the scaling factor I get the expected results. Why is this happening?

Bellow image, shows NDVI values of the same area before and after applying scale factor at Bands 4, 5.

[![enter image description here][1]][1]

USGS Website:
[![enter image description here][2]][2]


  [1]: https://i.sstatic.net/UBdEJ.png
  [2]: https://i.sstatic.net/51RDH.png