SonyAlphaRumors.com reports that the standout feature of the long-expected A7IV – the downmarket cousin of the long-ago-released A7R IV – will be 15 stops of dynamic range (DR). If true, it would be a significant benefit. Sony traditionally has claimed a very high DR in new cameras, which has always turned out to be several times less than advertised. The most recent release in this line, the A7III claimed “up to 15 stops” of DR only to be tested to have 12 stops. A chart of DR for Sony’s various cameras that claimed close to 15 stops can be found here.
The B&G sales copy on their website for the A7III quotes Sony literature, indicating the camera has “the ability to capture an impressive 15-stop dynamic range at low sensitivity values.” Bill Claff’s excellent PhotonsToPhotos.net site shows the database of actual measured performance of that sensor has about 8 times less (three stops) dynamic range than Sony claims.
The rumor indicates the camera will be out in mid-October, pending sensor availability… which is to say it won’t be out in October, and not likely until higher-margin cameras are meeting their supply requirements.