I am somewhat confused about how to react to Vija Celmins work. It is amazing from the perspective of photo realism how she manages to create the meticulous detail of her different subjects whether they are the sea, the stars or recreating rocks as above.
It is obviously that she painstakingly reworks these images and objects in minute detail and it is said that the work luminous in its reality. The degree to which she interprets tone is astounding and compulsive in many of her series of works.
In terms of helping with drawing clouds the degrees of tonality and luminosity are key to bringing such drawings to life. The working & reworking of the pieces builds over quite extended time to her creating these fabulous pieces.