The camera obscura in the Tower of Ulysses, St Geoge’s Castle (Castelo de Sao Jorge) in Lisbon was installed in 1998 by  Sinden Optical a UK company. A walkway along the wall top which links to the tower allows 360 degree view of the city.

Specification:

Focal length -  7.4 m

Lens diameter - 311mm

Screen - 2.25 m diam.

In 1644 the Villavicencio family constructed this baroque palace, which was built over the ruins of an old Islamic palace. The camera obscura is on the top floor of the tower giving a birds-eye view of the city and surrounding countryside. Built by Sinden Optical in 1998 it has two mirrors available for use  - one is resilvered each year. Sometimes closed, as the optics are vulnerable to high winds.

Specification:

Focal length -  4.9 m

Lens diameter - 300mm

Screen -  curved 2 m diam.

View of the entire

St. Georges Castle

Cadiz is famous for its watchtowers built during the 18th c. The Tavira tower was part of the palace of the Marquis of Recano and was designated as the official watchtower for the town, being the highest lookout point at that time.

The camera obscura was built and installed by the Sinden Optical Co. in 1994 as a result of a visit to the camera obscura in Edinburgh by Belin Gonzalez. She was inspired to replicate it in Cadiz and responsible for other camera obscuras built by Sinden Optical in Spain.

Specifications:

Focal length - 5.18 m

Lens diameter - 305 mm

Screen -  approx. 2 m dia.

The castle was completed in the 15th c. and is surrounded by a moat , with crenellated walls, towers and a drawbridge entry.

The camera obscuras are in one of the corner towers overlooking the entrance to the castle, where reputedly the contessa could scutinise visitors prior to entry. The optics consist of a meniscus prism which forms an image on a concave screen mounted on a low table as shown in the lower photograph. The chamber has a round wall with the system replicated on the opposite side. 

Specification (estimated):

Focal length - 1.5 m

Prism length - 65 mm

Screen width - 650 mm

In the tower of the late baroque Lyceum - today a teacher training  college - is Hungary’s first astronomical museum, the Specula Observatory originally  built in 1776 by the Astronomer Royal Maximimillian Hell SJ who also designed the camera obscura .

Specification :

Focal length - 2.8 m

Lens diameter - 150mm

Screen - flat, estimated dia. < 1 m with

             image size < 600mm

CAMERA OBSCURAS (Permanent)

Further Camera Obscuras to be added - Site under Construction