It's often said that the M4/3 format is the digital inheritor of the 35mm film tradition. There are too many variables to make a direct comparison, including the evolution of lenses in the last twenty years and viewing technology, so I thought I'd stick to maximum print size that retains full resolution, close up.
This was triggered by a debate elsewhere where people claim to have made very large prints from micro four-thirds cameras, including a 7ft 4in (225 x 150 cm) image from a 16mp M4/3 file, on YouTube. It isn't news that small formats can produce extremely large printed images, exhibitions routinely contain prints several feet across, sometimes themselves reproduced from a small print source. Given sufficiently viewing distance there are no limits to print size, as billboard advertisements illustrate.
However in a domestic environment, or a gallery where framed images invite the viewer to look ever closer, sharpness and resolution have limitations that depend, among other factors, on the format used. There is a subjective element in determining how sharp is sharp, and sharpness isn't the only factor in determining what people think of as "sharpness", which is a mix of factors. Nevertheless I thought I'd do my own tests using optimum apertures and focal lengths, and especially by downloading files from lenses thought to be exemplary and resolving the highest possible detail on test charts.
My conclusion was that if you require absolute detail in a context like landscape, where the ability to discern and describe individual pieces of foliage and stones at distance is a way in to the subject matter, 16 x 12" is a useful working limit. Which happens to coincide with my experience of 35mm film over the years.
This may seem conservative, and there's no doubt many would be satisfied with much larger prints. Nor does it speak to the aesthetic qualities of the image, or the visceral effect size might have on the viewer, or the technical parameters of print technology. It's simply my appraisal of the potential of the micro four-thirds format for nose-to-the-glass examination some subjects and certain situations invite.
Any thoughts?