HENRI CARTIER-BRESSON -- At the Corcoran through May 17.

The best test of a photograph is whether it can stand alone, uncaptioned and unexplained. By that standard Henri Cartier-Bresson long has been counted at least first among equals in his art, as the exhibition opening Saturday at the Corcoran Gallery reaffirms.

It is the first comprehensive showing of his work in a decade, and Cartier-Bresson, now 72, himself selected the 156 photographs from the full half-century of his career.

What a bold man he is. How skillful, how fast, how sly.

"In photography you have to be quick, quick, quick," he has said. "Like an animal and a prey. Vroom! Like this you grasp it and take it and people don't notice that you've taken it." I once had the pleasure of tagging along with Cartier-Bresson and a friend as they walked for several blocks in Manhattan. During those 20 minutes or so he took four photographs, but the fact that he had done so did not register on me until later.

So proud and sure is Cartier-Bresson that he usually identifies his pictures only by the place and year they were taken. I wish he wouldn't go even that far; when he shows me two whores peering from their cribs I know instantly who they are. A moment later I know less, as their fear and uncertainty are revealed. A while longer and they have developed into two people I will never know. If I had seen first from the caption that it was taken in Valencia in 1933 I would have seen less in the photograph.

My favorite frame from Cartier-Bresson is the portrait that appears on this page. I would like it better still if he had not told me what the old man is, because that interferes with what the photograph's own testimony about who he is. Both man and picture are diminished.

But these are quibbles about a great artist's work.