Are mechanical shutters the next step beyond camera mirrors? It’s all good, right?

Are mechanical shutters the next step beyond camera mirrors? It's all good, right?

The path to hell is said to be built with good intentions, and it appears that every advancement in camera design makes perfect sense. Mirrorless cameras are possibly the most famous example, a development that allowed a single AF system to be used for both viewfinder and live view shooting, making devices smaller and simpler.

Mechanical shutters are almost expected to follow. After all, why utilise physical shutter blinds when a sensor can be electronically’read’? Many cameras now have both mechanical and electrical shutter modes, with the latter providing far faster’shutter speeds.’ Some cameras, such as the Sigma fp and fp L, have abandoned the mechanical shutter entirely, and electronic shutters are a need for video shooters – you can’t have a mechanical shutter slamming up and down 30, 60, or even 240 times per second.

So, why haven’t electronic shutters taken the place of mechanical shutters?

Electronic shutters have a difficulty, and the bigger the sensor, the bigger the problem. In an ideal world, every camera would have a ‘global shutter,’ meaning that the entire sensor would be read at the same time. It’s the Holy Grail of sensor design (or, to stick with the digital theme, a digital 3D depiction of it).

There are a few specialised cameras with global shutters on the market already, but they aren’t common among the cameras we use for photography and video. The problem is that reading the entire sensor area in real time necessitates extremely fast readout speeds and processing power. And with the cameras we have now, we’re just not there yet.

Instead, most cameras’read’ the sensor in strips, similar to how scanners do, so that while the shutter speed may appear to be 1/32,000sec on paper, it is actually the time the photosites are exposed for – and they aren’t all exposed at the same time. Even though the shutter speed is much faster, reading the entire sensor could take as long as 1/30sec (our estimate based on current technology).

This poses problems with fast-moving subjects and fast camera movement, which is why filmmakers refer to the phenomena as “rolling shutter.” Verticals seem skewed and things become distorted if the subject or the camera moves too quickly for the electronic’scan.’ It can produce the ‘jello’ effect in videos.

Some manufacturers have circumvented this by using extremely sophisticated (and expensive) sensors and processing. With the Sony A9 II and Sony A1, Sony claims to have virtually eradicated rolling shutter, or shutter ‘distortion.’

Shutter distortion will undoubtedly be addressed in the near future, and electronic shutters will become commonplace.

Is this the end of the storey? Are motorised shutters next on the chopping block? Perhaps, and perhaps this is a good thing. But it’s possible that it isn’t.

Is there a difference between mechanical and electronic?

The arguments appear to be self-evident. Of COURSE (we say), a camera without a mirror is simpler… Is it, however? A mirror, some springs and levers, and a glass pentaprism are all that is required for a DSLR’s viewing system. It doesn’t require power-hungry circuitry, cutting-edge chip design, or a high-resolution tiny display panel.

While a mechanical shutter has many moving parts, an electronic shutter does not, it does require replacing physical mechanisms that have been refined for decades for ‘digital’ shutters that are almost but not quite there (agreed, for video, mechanical shutters are no good at all).

We appear to have blindly accepted the assumption that highly tuned physical systems are inherently inferior to solid state electronics… As a side note, we’ve seen in recent years that high technology can be one of the first casualties of global change.
There is also a backlash. Film cameras are now more popular than they have been in decades, instant cameras, with all their flaws and unrepeatable instant prints, are flying off the shelves, and Fujifilm has built a thriving industry out of creating cameras the way they used to be made. Some of us enjoy vinyl records and mechanical/automatic watches. The one thing they all have in common is that they all glorify the physical object rather than the technological.

Humans are primarily physical beings. Knobs and dials, leatherette, and levers are all favourites of ours. Glass and brass, as well as springs and spigots, are among our favourite materials. Modern cameras are technologically superior to those we used a generation ago, but have they lost their physical appeal in the process?

Cameras are fairly simple devices, consisting of a box containing the film/sensor, a lens for focusing the image, and a shutter for controlling the length of the exposure. How did we make everything so complicated, and why did we choose the soundless sterility of electronics over the elegance and subtlety of physical mechanisms?

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