Attached is a PDF explaining how the key tonal correction tools in Affinity Photo work. I previously had some confusion about exactly what each tool or adjustment did, both in the Photo and Develop Personas of Affinity Photo. My searches made it clear I wasn't alone. For example, what is the difference between Exposure and Brightness in the Develop Persona? I've answered that question and more in the attached PDF.
I spent a full day playing with the main tonal correction tools in the Photo and Develop personas of Photo v 2.0.4. I now understand what each tool does. More importantly, I know which tools I plan to use in each persona and why. This exercise cleared up a lot of confusion for me, so I thought I'd write up my findings and share it. I hope it is clear and helpful.
Happy editing!
Tonal Controls in AP.pdf