Andy Westlake puts Olympus’s super-fast mirrorless flagship camera through its paces
Olympus OM-D E-M1 Mark II review: Image quality
When assessing the E-M1 II’s image quality, it’s clear that it can’t match the best APS-C cameras (and in particular the Nikon D500) when compared at the same sensitivity setting. At any given ISO, noise is inevitably higher as a consequence of its smaller sensor. However, judged on its own merits, it’s absolutely no slouch: the sensor delivers highly detailed results at low ISOs, and still gives very usable image files up to ISO 3,200. So while it may not be the best for its price, it’s still very good indeed.
With its brand-new 20MP Four Thirds sensor, the E-M1 Mark II scores quite creditably in our Applied Imaging tests. A high of 12.7EV measured at its ISO 64-equivalent Low setting indicates plenty of scope for teasing out extra shadow detail from raw files. Raising the sensitivity setting shows a progressive decrease in dynamic range, with the sensor delivering good results up to about ISO 3200. Beyond this lower numbers reflect increasing levels of noise, especially in the darker areas of images. Values below 7EV at the top two ISO settings indicate significant levels of shadow noise.
At ISO 64, the E-M1 Mark II’s 20MP sensor provides a resolution of around 3,500 lines per picture height, which is a very respectable result, and slightly ahead of that we obtained from the PEN-F using the same lens (the excellent Olympus 60mm f/2.8 macro). This number drops gradually as the ISO sensitivity is raised and noise has an increasing impact on the image. By ISO 1,600, it’s down to around 3,000 l/ph, and at ISO 6,400 it drops to 2,800 l/ph. But it plummets dramatically at the top two settings, and at ISO 25,600 registers no more than 2,000 l/ph.
ISO and noise
At low ISOs, the E-M1 II provides very good image quality, with low noise and a good level of fine detail. The extended ISO 64 setting gives the cleanest images with minimal noise, but highlights clip to pure white sooner. Fine detail is maintained very well up to ISO 400, but beyond this noise (and noise reduction) starts to degrade fine detail. At ISOs 1600 and 3,200, image quality is still very respectable, and while fine low-contrast detail has mostly disappeared, this will only be evident in large prints. But there’s a more marked drop in quality at ISO 6,400, with shadow areas becoming muddy and colours starting to desaturate. The two highest sensitivity settings of ISO 12,800 and ISO 25,600 give poor results, and if you shoot a lot in very low light then buying a larger-sensor camera would make more sense.