A photographer reminisces about his photo that came to define the fall of Vietnam -- and the misconception about it that persisted for decades.
An excerpt:
By HUBERT VAN ES 
Published: April 29, 2005
ONG KONG
THIRTY years ago I was fortunate enough to take a photograph that has become perhaps the most recognizable image of the fall of Saigon - you know it, the one that is always described as showing an American helicopter evacuating people from the roof of the United States Embassy. Well, like so many things about the Vietnam War, it's not exactly what it seems. In fact, the photo is not of the embassy at all; the helicopter was actually on the roof of an apartment building in downtown Saigon where senior Central Intelligence Agency employees were housed.
It was Tuesday, April 29, 1975. Rumors about the final evacuation of Saigon had been rife for weeks, with thousands of people - American civilians, Vietnamese citizens and third-country nationals - being loaded on transport planes at Tan Son Nhut air base, to be flown to United States bases on Guam, Okinawa and elsewhere. Everybody knew that the city was surrounded by the North Vietnamese, and that it was only a matter of time before they would take it. Around 11 a.m. the call came from Brian Ellis, the bureau chief of CBS News, who was in charge of coordinating the evacuation of the foreign press corps. It was on!
The assembly point was on Gia Long Street, opposite the Grall Hospital, where buses would pick up those wanting to leave. The evacuation was supposed to have been announced by a "secret" code on Armed Forces Radio: the comment that "the temperature is 105 degrees and rising," followed by eight bars of "White Christmas." Don't even ask what idiot dreamed this up. There were no secrets in Saigon in those days, and every Vietnamese and his dog knew the code. In the end, I think, they scrapped the idea. I certainly have no recollection of hearing it.
A few more excerpts:
1. Note what he says about the Vietnamese stringers he worked with:
I was the only photographer left, but luckily we had a bunch of Vietnamese stringers, who kept bringing in pictures from all over the city. These guys were remarkable. They had turned down all offers to be evacuated and decided to see the end of the war that had overturned their lives.
2. The eternal journalist's lament:
After shooting about 10 frames, I went back to the darkroom to process the film and get a print ready for the regular 5 p.m. transmission to Tokyo from Saigon's telegraph office. In those days, pictures were transmitted via radio signals, which at the receiving end were translated back into an image. A 5-inch-by-7-inch black-and-white print with a short caption took 12 minutes to send.
And this is where the confusion began. For the caption, I wrote very clearly that the helicopter was taking evacuees off the roof of a downtown Saigon building. Apparently, editors didn't read captions carefully in those days, and they just took it for granted that it was the embassy roof, since that was the main evacuation site. This mistake has been carried on in the form of incorrect captions for decades. My efforts to correct the misunderstanding were futile, and eventually I gave up. Thus one of the best-known images of the Vietnam War shows something other than what almost everyone thinks it does.