The Vignette effect gradually darkens the outer edges of a photo, drawing attention to the center.
Tap and turn on Vignette.
Customize the effect:
Move the Exposure slider to change the strength of the vignetting effect (moving it into negative values will brighten the edges instead of darkening them). You can also enter a value from -200% to 200%.
Move the Black Point slider to adjust the contrast of the vignette effect (moving it into positive values will add more pure black values). You can also enter a value from -200% to 200%.
Move the Softness slider to adjust how gradually the edges should darken. You can also enter a value from 0% to 100%.