Finding out how cameras are built

I’ve always enjoyed taking things apart to discover how they work.  Usually, I can put them together so that they work again, but sometimes they are defunct, and then it’s fun to take them to components to really examine how the mechanisms. I had an Olympus camera that stopped working on a recent trip to Ireland (see here – and it was a goner no matter what, with a dead reed switch, it wasn’t carelessness with a breadknife!).  So, a perfect opportunity to spend a quiet hour last night stripping it right down.  The result is below

There were a few mechanically clever bits – for example, the viewfinder zoom function (viewfinder assembly is in the middle on the top row).  There were two lenses that needed to move at different rates as the viewfinder zoomed.  This was done using a single helical thread, but with variable thread width – then one lens tracked along the back edge of the helix, and the other along the front edge, with small springs ensuring engagement – all worked very neatly.  Another neat bit was how contacts were made around the lens assembly.  There were about 8 contacts to make, so the various flexible connectors had circular gold plated slightly convex pads – you can see two of them on the tails attached to the motor that is in the middle on the bottom row.  The actual contact was made by screwing an insulated washer down over the top of the stack of connectors, so making all the connections in the stack in a reliable but vibration robust way – very neat.  Finally, the entire extendable lens assembly was pretty cool, with internal cams meaning that full extension of the barrel, and zooming with internal lens assemblies moving at two independent rates up the barrel was done with a single mechanism.  There are few plastic mouldings that I’d regard as beautiful pieces of engineering, but this was certainly one (they are on the bottom row, but it’s hard to see since they are matt black).

There were also a couple of surprises.  The largest was that there is no aperture control at all.  High brightness situations are handled by a grey filter that gets flicked into the light path (you can see it on the top row near the right hand side, with the two shutter petals).  From a photography perspective that feels like a real miss – I wonder if the replacement camera will have it – I doubt it somehow since this seems broadly adequate and a whole lot simpler and smaller.  But, I do much prefer having proper aperture control.  The second surprise was the number of separate integrated circuits – there are about 8 or 9 (you can’t see them all below since some of on the backs of the circuit boards).  I can see how you’d get this number – e.g. overall processing, an A/D converter, a USB driver, a video driver, and memory chip driver and so on – but I’d expected 3 or 4 at a maximum, given how much space is at a premium, with many of the interfaces integrated at a  die level (i.e. on one chip) – but maybe this shows the age of the camera and newer ones are more integrated.

Exploded Olympus camera

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