For a more subtle vignette, use a lower number. The further I drag the slider in either direction, the more intense the vignette will be (it’ll either be a darker black or a brighter white). The exposure value when you do this will be positive (red arrow in the above image). If I drag the slider to the right, it will add a white vignette to my image. The exposure value when you do this will be negative (red arrow in the image above). So, if I drag the slider to the left, this will add a black vignette to my image. The first is called “Exposure.” This slider allows you to make the vignette either black or white, and controls the “value” – which basically means the amount of darkness (black) or brightness (white) – of the black or white vignette. There are four sliders you can adjust inside the Live Vignette panel. This is a non-destructive way to add filters to your images. This means the filter itself will be added to its own adjustment layer, which you can then double-click at a later time to edit the filter or make adjustments. The Vignette filter is what’s known as a “Live Filter” in Affinity Photo. This will bring up the “Live Vignette” panel (outlined in green in the image below). Once your image is open, add the vignette to it by going to Layer>New Live Filter>Colors>Vignette in the Menu Bar (red arrow in the image above). This will open your image as a new document. Select the image you’d like to use from the folder where it’s located on your computer and click “Open” (red arrow in the image above). To do this, open Affinity and go to File>Open.

You’ll of course want to open the image you’d like to add your vignette to inside of Affinity.

Affinity photo brightness menu bar