Filmmakers Ken Burns and Lynn Novick discuss their new PBS documentary series ‘The Vietnam War’ and the importance of remembering the war at the Vietnam Veterans Memorial.

The black-and-white photograph is fuzzy, perhaps out of focus.

It doesn’t matter. What the photograph captured almost half a century ago is still as clear and sharp as a gunshot.

A man in a uniform is pointing a .38 caliber silver revolver inches from the head of another man, whose hands have been handcuffed behind him.

The man holding the revolver displays no expression. The handcuffed man winces as the bullet is fired.

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Eddie Adams, who lived then in Bogota, N.J., took that iconic photo Feb. 1, 1968, in Saigon. It came to be known as the “street execution” of a captured Viet Cong operative by Gen. Nguyen Ngoc Loan, the chief of South Vietnam’s National Police.

At the time, Adams did not know this image would change history.

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If you’ve been watching the 10-part, 18-hour PBS-TV series Vietnam from acclaimed documentarians Ken Burns and Lynn Novick you’ve seen this photo.

You’ve seen others too. The National Guard soldiers’ shooting of a student in 1970 at Kent State University in Ohio is one.

By the time the series ends, you will see more.

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Vietnam was America’s first…