You either buy a standard with a published/pre-measured values, or you measure it against some other published standard. Or, you can make your own "white standard", e.g. by getting some barium sulphate (white powder) and squashing it flat. You can assume this is roughly 100% reflectance and very diffuse. So use this as your master standard, and measure your other standards against it with a camera that can do linear (RAW) images. Or buy e.g. an x-rite colour chart.
@@jTroscianko Thank you for your reply I bought a spydercheckr24. And thanks for this tool, seems to be awesome!. I will try to measure reflectance and brightness from frogs. I just started to learning how to use this tool in ImageJ. Do you have any suggestion about how to control the light. I am practicing taking pictures outdoor, but as you mentioned in your website in the forest, lighting conditions are unstable. Do you recommed to fix whitebalance with a software (e.g: Lightroom) before using the picture in ImageJ?
Linearisation modelling is not needed for RAW images right?
How do I know the reflectance values of my grey standard?
You either buy a standard with a published/pre-measured values, or you measure it against some other published standard. Or, you can make your own "white standard", e.g. by getting some barium sulphate (white powder) and squashing it flat. You can assume this is roughly 100% reflectance and very diffuse. So use this as your master standard, and measure your other standards against it with a camera that can do linear (RAW) images. Or buy e.g. an x-rite colour chart.
@@jTroscianko Thank you for your reply I bought a spydercheckr24. And thanks for this tool, seems to be awesome!. I will try to measure reflectance and brightness from frogs. I just started to learning how to use this tool in ImageJ. Do you have any suggestion about how to control the light. I am practicing taking pictures outdoor, but as you mentioned in your website in the forest, lighting conditions are unstable. Do you recommed to fix whitebalance with a software (e.g: Lightroom)
before using the picture in ImageJ?