Photo Advantage

Just be careful about taking close-ups of coins.
All of a sudden your coins start looking ugly and with LOTS of marks.
Even a PR-70 coin will show problems if the picture is blown up enough.

The pros at the TPG's do much of their grading WITHOUT a loupe.
If something appears to require a closer look they'll use something in the range of 3x to 5x.
And only if there's a tough attribution to make will they go as high as 10x.

Fly speck collectors will use a stereo microscope up in the 40x to 60x range.
They not generally after "error" coins as an end.
They are after differences that help identify minting discrepancies.
CLASSIC CASES: Doubling and warping on the reverse of US Memorial cents. Look at some of the articles in Coin World.

You have to develop a different sense of grading, an understanding of what digital photography does to coins. It's a whole separate "grading scale," factoring your knowledge of photography. And it's imperative if you're going to grade from images, because if you post a coin actual-size on the forum for grading you'll get laughed at.