itself." pp. 36–37. Popular Photography & Imaging, Volume 71 Number 2; February 2007. The ISO hot shoe became a standard SLR feature in the early 1970s. However, in 1971, SLRs using "dedicated" electronic flashes with automatic flash exposure control began appearing with the Canon FTb (Japan). They used ISO-style shoes with extra electrical contacts. Each SLR brand used incompatible contact configurations and the time of use-any-flash-with-any-SLR passed by the late 1970s. Note, although the hot shoe had been de facto standardized in the 1950s, the International Organization for Standardization did not promulgate its ISO 518 hot shoe specification until 1977. 1965 Canon Pellix (Japan): first (really second after french Focaflex of 1959) pellicle reflex mirror SLR.Lea, pp. 44–45Shell, pp. 43–46Wade, Collector's Guide. pp. 140–142 Virtually all SLRs use fast-moving reflex mirrors that swivel out of the way to take the picture, causing mirror shock vibration, blacking-out the viewfinder and delaying shutter firing. Camera shake can blur the image and the subject (which might have moved) cannot be seen at the instant of exposure.Goldberg, Camera Technology. p. 150Herbert Keppler, "SLR: Is the price you pay for modern SLR conveniences too much?" pp. 23–24, 25, 28–29, 92. Popular Photography, Volume 63, Number 12; December 1999. A fixed semi-transparent pellicle reflex mirror, reflecting 30% of the light to the viewfinder and transmitting 70% to the film, prevents camera shake and viewfinder blackout, and reduces shutter lag time at the costs of a dimmer viewfinder image, longer exposure times and possible image quality loss.Herbert Keppler, "SLR notebook: Want faster autofocus? Less vibration and noise? Buy a Canon EOS RT." p. 30. Popular Photography, Volume 96 Number 12; December 1989. Modern instant return mirrors are fast enough and have efficient enough shock damping systems that the trade offs are not usually considered worthwhile.Herbert Keppler, "SLR: For sharpest images, do you really need mirror lockup? If so, why don't all top cameras have it?" pp. 18, 20, 22, 24, 64. Popular Photography, Volume 63 Number 6; June 1999. Pellicle mirror SLRs are very rare and are usually specialized designs for ultra-high speed (10+ frames per second) sequence shooting.Stafford, Hillebrand & Hauschild, pp. 28–29 1966 Praktica Electronic (East Germany) first SLR with an electronically controlled shutter. Used electronic circuitry to time its focal-plane shutter instead of spring /gear/lever clockwork mechanisms. 1966 Konica Autorex (Japan; called AutoReflex in USA): first (really second after Soviet russian Kiev 10 Automat