1 Reply Latest reply on Jul 11, 2017 7:56 AM by Rikk Flohr - CM

    Kevlin scale to -100%-100% scale conversion

    jessiefs

      Does anyone know what Kelvin values convert to on the -100%-100% temperature scale on Lightroom?

       

      I have scrolled through similar discussions but so far none have an adequate answer. What I do know so far though is that:

      • Raw photos being edited in Lightroom will display the kelvin scale, whereas JPGs and TIFFs will display the -100% - 100% scale as the white balance/temperature is set and any adjustments can only be relative.
      • Converting to a DNG file can supposedly help

       

      What I am trying to do is replicate the treatment of an online photo on my own photos (I like the filter), and having found the metadata using the Exif Tool by Phil Harvey, I now know that the colour temperature is 6,300. However, unfortunately I only shot in JPG and as such I am unsure what value to input on my temperature scale that is equivalent to 6,300K. I tried importing as a DNG, as well as exporting as a DNG, but Lightroom only tells me the conversion is not possible for files that are not RAW and keeps my file as a JPG.

       

      Any help would be greatly appreciated

        • 1. Re: Kevlin scale to -100%-100% scale conversion
          Rikk Flohr - CM Adobe Employee

          The Kelvin scale is only applicable to raw files. In these files, the White Balance hasn't yet been cooked into the file. The degree-value is appropriate to matching (or creating the effect) of light of a specific color.

           

          When you create a Tiff, JPEG, PSD, PNG, the White Balance has been baked into the file and the full range of color response is no longer possible. Once this happens the degree value in the Kelvin range is no longer applicable. With these files you can adjust them within a limited range that is defined as -100 to +100 in value along the Blue-Yellow and Green-Magenta axes.

           

          There is no direct conversion because you are really talking about two different things.

           

          Consider this example:
          If you have a raw file that is set to 6300° and then create a JPEG. 6300 is the center point of both sliders. No adjustment necessary.

          If you have a raw file that is set to 5500° and then create a JPEG. 5500 is the center point of both sliders. Slider adjustment one direction is required to get a similar temperature to the original example.

          If you have a raw file that is set to 8000° and then create a JPEG. 8000 is the center point of both sliders. Slider adjustment the other direction is required to get a similar temperature to the original example.

          2 people found this helpful