flash photo of a foliose lichen – the image is sharp and has good depth-of-field, but the dark background is somewhat “un-natural”……… 131/5000 Did you mean: flash photo of a foliose lichen – the image is sharp and has good depth-of-field, but the dark background is somewhat “unnatural”. Foto de flash de un liquen folioso: la imagen es nítida y tiene buena profundidad de campo, pero el fondo oscuro es algo “no natural”.