22.5 MB (1.4 MB compressed)
2334 x 3372 pixels
19.8 x 28.4 cm ⏐ 7.8 x 11.2 in (300dpi)
ROYAL GREENWICH OBSERVATORY / SCIENCE PHOTO LIBRARY ROYAL GREENWICH OBSERVATORY / SCIENCE PHOTO LIBRARY
Nineteenth century model of Sir Isaac Newton's reflecting telescope, known also as the Newtonian telescope. This was the first reflecting telescope to be built, around 1670. It is much the same type used by amateur astronomers today. It has a paraboloid primary mirror & a flat diagonal mirror that reflects the light into an eyepiece mounted on the side of the tube. A 45-degree prism may be used in place of the diagonal mirror. The Newtonian telescope had a focal length of about 15 centimetres & magnified some 30 times.
Model release not required. Property release not required.