Been trying to find a 16mm Specto to loan out and find that pretty much all I have is Analysers. Here are some pix of one I played with.

Note in pic 1 a single-frame button (arrowed) that you can push, when the speed control is set to zero, for very slow advance. The 2fps setting gives an intermittent motion - a couple of frames at a time. The 16fps speed seems slow, but not only is there no speed control other than the 0-2-16 lever, there is no inching knob either, its place being taken by a handle for backwinding. I don't understand most of the additional bits you can see in pix 2 &3. In pic 4 arrowed is what looks to be a twin-track commutator-like thing with brushes contacting it from the block to the right. In pic 5 you can just see the edge of the heat shutter that comes across for stills. Curiously, this seemed on this machine to make no difference to the light level, which leads me to suspect something is not working right. Anyway, you will be unsurprised to hear this machine, too, has joined the great projector conspiracy. The backwind handle, having been bent at its weakest point, not only broke but also now refuses to come off - it did once but not a second time.

The problem with Analysers as projectors is that the speed seems to be fixed and 16fps, on this machine at least, is just too slow for a modern audience. The light output, naturally, has to be reduced; this one has a 250w lamp. I need to understand them better; I have no idea for instance what the extra socket on the front is for. Has anyone got any instructions I can get a copy of? And does anyone know why there seem to be so many about - I only know of RAF use for analysing films of bombing etc; does anyone know of any other uses?

Here are some close-up pix of a dual-gauge 8/16 Specto.

 These give you some idea of how the gauge change is effected. Basically, all Specto's use the same gearbox; the difference between 8mm and 9.6/16mm machines is down mostly to the size of the sprocket drive from the gearbox. Here you can see the mechanism from the front that moves the main drive shaft on which are two sprockets. The iner, larger sprocket has a conventional arrangement, with the inner chain driving the two chain sprocket drives to the film sprockets. However, the operation of the gauge change lever operates some form of clutch which disengages the large drive sprocket and presumably leaves it to freewheel. the drive shaft then engaging with the smaller sprocket. The drive then goes via the outer chain to the outer of the two bottom sprockets, which is rigidly connected to the inner sprocket, so passing the reduced speed drive to the upper sprocket via the inner chain. Clear so far? The Specto people were highly ingenious, as even this limited example shows. The analyser machines were a whole order of magnitude more complex.

Incidentally, I no longer quite understand why I included the middle pic,which seems to show some sort of heat filter, usually associated with a still frame or very slow motion capability. It mite belong to an analyser rather than this machine.