Today’s Question: While I don’t totally understand the numbers, I’m accustomed to the white balance adjustment in Lightroom Classic showing a temperature value of somewhere around 5,000 (sometimes considerably lower, sometimes a bit higher). However, with some images the value for the temperature is zero (until I apply an adjustment). I can’t figure out why some images have a range I’m expecting, and others have a zero value to start with. Any ideas?
Tim’s Quick Answer: The “normal” temperature scale you’re referring to is shown for raw captures. For other supported image formats such as JPEG or HEIC photos, the scale is an adjustment with a default value of zero.
More Detail: For most supported image formats in Lightroom Classic the Color Temperature (Temp) and Tint sliders operate in much the same way as many of the other adjustment sliders. For the Temp slider, that means the default for images such as JPEG and HEIC captures is a value of zero, with the ability to shift toward blue with a minimum value of -100, or toward yellow with a maximum value of +100.
For raw captures, the Temp adjustment represents color temperature values in degrees Kelvin. The actual value represents the number of degrees Kelvin representing the color of the light being compensated for. For example, if the illumination of the scene was a rather blue light, the value for Temp would be relatively high, indicating the temperature of the light being compensated for. That would result in a shift toward a more yellow (or at least less blue) appearance.
For all image types (including raw captures) the Tint slider functions mostly the same. You can shift toward green with a minimum value of -150 for raw captures and -100 for other image formats. When adjusting toward magenta the maximum value is +150 for raw captures and +100 for other image formats. The only other difference among image types is that for raw captures the default value for Tint will be based on the in-camera white balance setting. For all other image types the default value is zero.
The point is that the key difference in the scale for the Temp slider relates to raw captures versus other standard image types. But the overall function of the Temp and Tint sliders is essentially the same in terms of actually adjusting color for a photo.