Price (RRP): $3,099
The Sony Alpha7 III digital camera is an amazing device, managing to stuff a full frame sensor into a remarkably compact body.
Full Frame Sensor
Let’s start by positioning this camera in the Sony lineup. Sony’s top of the line model is the Alpha9, also a full frame model, priced at nearly $6,000. You can step down through the Alpha99 and Alpha7R (we reviewed last year’s version of this one here.)
The current Alpha7R III costs $4,999. The next step down is this model, the Sony Alpha7 III. Losing the “R” in the model name saves the purchaser quite a bit of money, since this model sells for $3,099. (All these prices are for camera bodies alone. Lenses are extra.) The other major change between the Alpha7R III and the Alpha7 III is the sensor. The Alpha7R III has a resolution of 42.4 megapixels. The Alpha7 III has a mere 24.2MP. The pictures come out at a maximum of 6,000 by 4,000 pixels.
It wasn’t very long ago I regarded 24.2MP as an astonishingly high resolution. You can make a solid case that this is considerably higher resolution than the best 35mm film shot under optimum circumstances.
The sensor is back-illuminated. That term is misleading. As with the human eye, image sensors traditionally have the wiring and active matrix drive structure between the lens and the photosensitive layer. “Back-illuminated” sensors move most of that stuff behind the photosensitive layer. That increases sensitivity, typically by around 0.5 stop.
Full frame means that the sensor is (approximately) the same size as the negative of a 35mm film camera. In this case, it’s 35.6mm by 23.8mm. Negatives on actual 35mm film measure 36mm by 24mm (give or take, as is so often the case with analogue systems.)
Displays and lenses
Despite the large sensor, the camera is mirrorless. Which means that what you see through the viewfinder is not an optical look down the barrel of the lens, but a mini display showing the image falling on the sensor. That mini display uses OLED technology and has XGA resolution. Camera makers weirdly use “dots” rather than pixels to describe their displays. It has “2,359,296 dots”. Well, technically yes. But in terms of pixels, which is what counts, it comes to 786,432. That is, a little under 0.8 megapixels.
Is that too low? No. That’s plenty of resolution for the purpose. The rear monitor has “921,600 dots”, which means VGA (640 x 480 pixel) resolution. Also, that’s plenty for a 7.5cm display. The viewfinder has full dioptre adjustment so it ought to work with all eyes. It worked well with mine. Its magnification is 0.78x with a 50mm lens.
The display can fold out and be tilted up by 107 degrees and down by 41 degrees. That’s plenty for framing those difficult overhead shots, or for shooting from ground level without having to get down on your tummy.
The camera uses Sony’s E-Mount for lenses. Which means it can use the highest quality lenses Sony has on offer. Sony included the FE 2.8/24-70GM lens with the review camera. Full frame cameras tend to need fairly large lenses by their very nature. This one is also fast – f/2.8 over its full range – which means a big opening. So it’s large, heavy and expensive: $3,099.