The discussion centers on the phenomenon of diffraction spikes observed in astrophotography, particularly in images of bright stars. These spikes are caused by the internal support structure of telescopes, specifically the spider vanes that hold the secondary mirror, commonly found in Newtonian reflectors. The number of spikes—typically four—depends on the design of the telescope and the brightness of the star, with some telescopes producing more spikes due to additional supports. The conversation also touches on the visibility of these spikes in relation to the brightness of stars and the optical characteristics of different telescope types.
PREREQUISITESAstrophotographers, telescope manufacturers, and astronomy enthusiasts interested in understanding the optical effects of diffraction spikes and improving their imaging techniques.
The rays in the TV camera images are caused by internal reflection/diffraction off of the lens's iris. Closely related to the telescope images, but of course there are no mirror supports in the TV camera.pinball1970 said:Top of pops was the usual one as there were always visible studio lights.
Thanks the guys gave a few examples, I always liked them (spikes) in older 1970s studio showsJames Demers said:The rays in the TV camera images are caused by internal reflection/diffraction off of the lens's iris. Closely related to the telescope images, but of course there are no mirror supports in the TV camera.