Available online
Description
The programme explains how image intensifiers are used to produce images of faint objects and explores the principles underlying the intensification process
The programme explains how image intensifiers are used to produce images of faint objects and explores the principles underlying the intensification process
| Module code and title: | ST291, Images and information |
|---|---|
| Item code: | ST291; 02 |
| First transmission date: | 10-03-1977 |
| Published: | 1977 |
| Rights Statement: | |
| Restrictions on use: | |
| Duration: | 00:24:25 |
| + Show more... | |
| Producer: | Andrew Millington |
| Contributors: | Barrie Jones; Alan Walton |
| Publisher: | BBC Open University |
| Keyword(s): | Astronomy; Ebitorn tube; Electronograph camera; Galaxies; Image intensifiers; Microdensitometer; Photographic film; Photons/electrons; Television camera |
| Footage description: | Barrie Jones introduces the programme standing in an unlit studio. The picture of his face, which appears on the screen, is being taken by an ebitron tube t.v. camera which employs image intensification techniques. Jones examines some of the principles which underly all image intensifiers. He builds up a diagram as he talks. Alan Walton, at the 98 inch Isaac Newton Telescope, Herstmonceux, describes one type of image intensification process, one not involving electron amplification, which is used by astronomers studying weak galactic sources. He holds an image intensifier of the type used in the telescope and points out its various parts. Walton next explains how the information on the image intensifier's electron sensitive film is processed by use of a microdensitometer and is then projected on a VDU in the form of a galactic contour map. Shots of the VDU. Barrie Jones introduces the second type of image intensifier, a four stage intensifier. Alan Walton holds an image intensifier of this type and points out various parts. He then examines an unencapsulated intensifier and finally takes up some component parts and assembles them in the correct order explaining as he does so, how the system works. Barrie Jones briefly introduces Alec Boksenbyg who goes on to explain how this system is used in practice at Herstmonceux to record light from very faint astronomical sources. He points out the various components of his apparatus and then displays an image of a galaxy on a monitor screen. Boksenberg improves the image by eliminating noise electronically and finally by building up a computer enhanced image on an oscilloscope screen. Barrie Jones discusses advantages of image intensifiers other than just their great sensitivity. He uses graphs to point out their superiority in sensitivity, dynamic range and linearity over conventional photography. |
| Master spool number: | DOU2306 |
| Production number: | FOUS721L |
| Videofinder number: | 2113 |
| Available to public: | no |
