Cincinatti ? A rare daguerreotype of abolitionist John Brown is up for bids today, about seven years after an auction of the last such photograph garnered six figures.

Experts say probably no more than a half dozen original daguerreotypes exist of the man best known for his ill-fated raid on a federal arsenal in Harper’s Ferry, Va.

Brown was born in 1800 in Connecticut, lived in Ohio for a time and was a free-state activist in Kansas before the October 1859 raid that he hoped would inspire an anti-slavery rebellion.

He was wounded and captured, and was tried and hanged by the state of Virginia for treason two months later.

Although revered by some for his anti-slavery militancy, Abraham Lincoln called him a “misguided fanatic.”

A daguerreotype was an early form of photography popular in the 1840s and 1850s in which an image is formed on a chemically treated metal plate. The method was named for Louis-Jacques-Mande Daguerre, the French painter who developed the process.

The photo being auctioned today remained in Brown’s family through five generations until descendants contacted Cincinnati-based auctioneer Wes Cowan.

“It’s the most important photograph we’ve handled in our 13 years of existence,” said Cowan, an occasional appraiser on “Antiques Roadshow” and host of the PBS series “History Detectives.”

He estimated a sale price of $60,000 to $80,000.

The last daguerreotype of Brown that sold at auction went for $120,000 about seven years ago, according to Kansas historian Karl Gridley, and is displayed at the Smithsonian Institution’s National Portrait Gallery.

“That one shows him holding a flag with one hand, and one hand raised as if taking an oath and has a lot of drama to it,” Gridley said.

“This one is more of straight-on shot.”

In it, Brown is wearing a jacket with several buttons – the same one or similar to the jacket in the National Gallery portrait – and has his arms crossed in front of him.

“This extremely rare and riveting portrait is doubly significant not only as one of the earliest daguerreotypes of the revolutionary abolitionist but also because the long-lost image was made by the remarkable African-American photographer Augustus Washington,” said Theresa Leininger-Miller, an art history professor at the University of Cincinnati.

Washington had been a teacher but turned to photography to pay off his college debts. He had one of the most successful daguerreotype studios in Hartford, Conn., before emigrating to Liberia, where he became a planter, politician and newspaper editor.

The auction catalog describes the portrait this way:

“A self-assured and clean-shaven Brown stares intently and directly at the viewer with steely, blue-gray eyes and the hint of a knowing smile as the left side of his mouth upturns slightly and puffs out the cheek near his hawk-like nose.”

Later, better-known portraits show Brown with a long, bushy beard.

Experts believe the National Gallery daguerreotype and the one offered Friday were made during the same sitting at Washington’s Hartford studio in 1846 or 1847.