FORMAT: BetaMovie     DATE: 1985 PRICE: £? [2005: £?] 37x18x15 cm 2.5 kg

The BMC-500 was the last BetaMovie camcorder produced. It now has autofocus, a date/time generator, and more information displays and controls. The styling is much more modern, and no longer looks like an overlarge cine camera -- in fact it's difficult at a glance to tell it from full-size VHS camcorders of the same era.
However, like the earlier BMC models, it is a record-only machine, with no in-camera playback. The viewfinder is optical, but the Single Lens Reflex system shows you exactly what you're taping, and has a useful split-screen focusing guide. The controls - such as they are - are logically laid out, with a combined power and start/stop button, and the autofocus (which can be operated constantly or just when the button is pressed) is on the barrel on the left.
The date/time generator is on the left side, and the LCD display is also used to show status information like the tape counter, battery state and mode indicators.

The autofocus system is infra-red, with a large transmitter beside the lens and a receiver above it. Pulses of invisible infra-red light are sent out, and the time it takes for the reflection to come back tells the camera how far away the subject is. IR autofocus works well, but is easily confused - for example, when filming through a window it can focus on the glass, and when filming rough or complicated surfaces (like plants or dark fur) it doesn't focus on anything at all!

Interestingly, the earlier BMC-200 -- which was the first to have autofocus -- used a "fuzzy logic" system which analysed the actual image and tried to make it as sharp as possible. This is a much more sophisticated approach, and theoretically much more reliable, so it's surprising that Sony went back to a more primitive system in the 500.

The most important technological change is that the BMC-500 uses a solid-state CCD chip to pick up the image -- all the other BMC machines used tubes. CCDs are much more robust than tubes, and are smaller, lighter and less power-hungry, so as soon as CCDs arrived, tubes were obsolete.
The BMC-500 was a good machine, but by 1985 there were VHS and VHS-C machines with full playback, so it didn't compare well. And, of course, the parent Betamax format was in deep trouble; without Betamax, BetaMovie was useless. Luckily, Sony's 8mm format was about to be released to save the camcorder market for them, so the death of BetaMovie was not as disasterous as that of Betamax itself.