Blackmagic Forum

I need to adjust exposure using the stops, how can I do it in Fusion? (attached screenprint of exposure stops in Nuke).

Exposure stops are exponents on Gain. The formula is Gain = 2^stops

Here's a quick Brightness/Contrast node that implements it:

Code: Select all

{
   Tools = ordered() {
      Exposure = BrightnessContrast {
         CtrlWZoom = false,
         NameSet = true,
         Inputs = {
            Gain = Input { Expression = "2^Exposure", },
         },
         ViewInfo = OperatorInfo { Pos = { 954.667, 60.697 } },
         UserControls = ordered() {
            Exposure = {
               LINKS_Name = "Exposure",
               LINKID_DataType = "Number",
               INPID_InputControl = "SliderControl",
               INP_Default = 0,
               INP_Integer = false,
               INP_MinScale = -5,
               INP_MaxScale = 5,
               INP_MinAllowed = -1000000,
               INP_MaxAllowed = 1000000,
               ICS_ControlPage = "Controls"
            }
         }
      }
   },
   ActiveTool = "Exposure"
}


edit: Oh, and this does need to be applied to a linearized image, as exposure is a physical ratio. Applying it in log or some screen-relative color space will give you incorrect results.