Liébert's concept was unique -- it was a closed structure that could be installed outside, normally on a rooftop. Compare that with todays outdoor cams. It was also built with a rack-and-pinion movement, allowing it to be rotated effortlessly toward the light, and with minimal vibration.
He patented a solar enlargement technique that improved upon earlier designs, such as David Acheson Woodward’s 1857 solar camera. Unlike Woodward’s model, which used a mirror to reflect sunlight and required frequent adjustments,
#AlphoneJustinLiébert’s design eliminated the mirror, directing sunlight through the negative with a hand-operated drive to keep the condenser lens focused on the sun. This reduced vibrations and blurry exposures, though it still needed adjustments and was sensitive to external conditions like wind.
His solar camera could produce enlargements up to 17¾ × 23¼ inches from carte-de-visite-size negatives (3½ × 2½ inches) in about two hours, a significant achievement given the slow photographic papers of the time, such as salted paper and albumen. Liébert’s design was more practical than earlier models and became widely used in
#NorthAmerica, while Woodward’s remained popular in France.
His solar camera was part of a broader movement to meet the growing demand for larger photographic prints, as patrons sought bigger portraits without the need for cumbersome large-format negatives. The device was typically set up on rooftops to minimize disturbances and maximize sunlight exposure, which was critical due to the low sensitivity of early photographic materials.