The discovery of two photographs believed to be of President Lincoln in profile was presented last month at a very appropriate event, the Lincoln Forum in Gettysburg, Pa., where scholars and students of the 16th president gather each November to discuss new works and discoveries about the man. Although not everyone was convinced, many were willing to say the two successive images most likely included the president as he was arriving at the stage to deliver the Gettysburg Address on November 19, 1863.

The finding is an extraordinary event. Only about 125 known photographs of Lincoln are known to exist.

“A new photograph of Lincoln is very precious and very rare,” the vice chairman of the forum and a leading authority on Lincoln, Harold Holzer, said. “In all probability, this is a Lincoln image, but you just want to yell, ‘Turn around!’ so we could see his full face.”

John Richter and Bob Zeller, officers of the nonprofit Center for Civil War Photography, included the discovery in a dramatic presentation of a series of stereographs on Lincoln and the Civil War.

The audience wore 3-D glasses to transform the stereographic paired images into a single three-dimensional image. In the midst of 162 images are two back-to-back images of the crowd at the cemetery dedication, taken by Alexander Gardner.

In the distance is what appears to be the official procession, including a man on horseback. A close-up view of the rider shows a familiar profile and the signature black stovepipe hat.

The image of Lincoln in the original photo is too small to see with the naked eye, but when magnified 60 times, his head and shoulders can be discerned above the crowd. “The stereograph was the View-Master of its day,” Mr. Richter said after the presentation. “There were thousands and thousands of these stereographs made. They were very popular. People could sit in their parlors and view Gettysburg or Egypt. I like them because you can move into the picture and kind of walk around among the people or objects. You can’t do that with a flat print.”

Mr. Richter has collected Civil War stereographs for 20 years, and he made this Lincoln discovery on a free Library of Congress Web site where 7,000 images are digitized. The library has many of the original negatives.

“I noticed there were three negatives from the dedication that were taken close together,” he said. “That struck me as odd because of the difficulty and cost of taking pictures back then. I also noticed the camera was not pointed at the stand but more toward the right. I zoomed in, and that was when I saw this figure.”

Mr. Zeller, who is the president of the Center for Civil War Photography and also a stereograph collector, helped Mr. Richter produce an electronic image greater than the usual 12 megabytes from two of the negatives. The image was 50 megabytes, Mr. Richter said.

“I was able to zoom in even closer,” Mr. Richter said. “I was thrilled with what I found. I am convinced it is Lincoln.”

Mr. Zeller said he is 98% sure it is Lincoln.

One of the newly enhanced images shows Lincoln passing by a row of soldiers, and a second shows him saluting them. The third is not as clear.

Although the attention that comes with such a discovery is welcomed by Messrs. Richter and Zeller, there is no financial benefit. The photographs belong to the public and can be seen at the Library of Congress Web site, lcweb2.loc.gov/pp/pphome.html, after entering “stereograph+civil war” in the search field, or at the Center for Civil War Photography Web site, www.civilwarphotography.org.

Mr. Zeller, of Trinity, N.C., is a freelance writer and Mr. Richter, of Hanover, Pa., works for a mail-order music store. The two have given many illustrated talks about stereographs and plan to continue. They said they would like to publish a book about their work.

Mr. Holzer said the image, though not a portrait with Lincoln facing the camera, is still extremely important.

“Anything we can still add to the Lincoln visual archives is a miracle,” he said.