Leaving some photos grainy is an art form, and works well in some instances...often suggesting things far beyond the given subject. However, in this case i wanted clarity.
There are many benefits to today's digital photography. One benefit is so often demonstrated by the ever popular "selfies" ! So often we see a selfie that taken face on..makes the nose look exceptionally large, exaggerating the closer parts.
For one thing, an excellent portrait can be taken at a distance, since with today's high res, it can be enlarged greatly, without any visible loss of sharpness.
Of course, there is the benefit of 'no cost' multiple shots. Where previously, a photographer would have to take many shots and then develop the film, print and work with the photos... What a relief, just scan your photos and dup those you don't like.
Now, I am a high-tech troglodyte, so don't ask me tech questions. ..But for instance, in the photo below, which is one of a series my son shot for the lady's swim suit collection..and for the sport board marketer..
I have watched him process many such photos, and on his equipment, he can draw the young lady's photo so close, that you can get a clear view of each eyelash ..or check closely the edges of the decals on the board.
Of course, one cannot do it with our laptop, since it cannot handle the pixel count.. Yet, by enlarging and enlarging again, one can see that it is far better than the old, grainy stuff!
