Image quality compared to OM-D E-M5

Olympus has used the same resolution sensor for the E-M1 as is in the OM-D E-M5, but with its on-chip phase detection, it's not identical. The E-M1's lack of an anti-aliasing filter promises more detail, and Olympus says the TruePic VII processor can fine-tune sharpening for improved JPEG image quality. We decided to look at the E-M1 side-by-side with the E-M5 to see if we could spot any clear differences.

Landscape with Panasonic 14-45mm F3.5-5.6

Here we've shot a landscape using the Panasonic Lumix G Vario 14-45mm F3.5-5.6 ASPH OIS, the unassuming little kit zoom for the first Micro Four Thirds camera, the DMC-G1. It doesn't look like much from the outside, but the 14-45mm is actually impressively sharp.

Olympus OM-D E-M1
Olympus OM-D E-M5
E-M1, 14mm F3.5 E-M5, 14mm F3.5
100% crop, centre 100% crop, centre
100% crop, corner 100% crop, corner

Here we can see that the lens delivers lots of detail in the centre of the frame. The E-M1 shows lots of false detail and aliasing in the fine structure of the grass, typical of a camera without a low pass filter. But as it happens, the E-M5 shows almost exactly the same thing, too, due to its already-very-weak low pass filter. Overall it's difficult to spot any real difference here at all. In the corner crops, the main difference lies in the E-M1's suppression of chromatic aberration, which is pretty effective.

Landscape with Olympus 12-50mm at F16 - diffraction

Olympus says that the E-M1's TruePic VII processor is able to provide better-optimised sharpening at small apertures, and help overcome the softening effects of diffraction. To illustrate this, here's the same landscape shot at F16, but this time with the Olympus M.Zuiko Digital ED 12-50mm 1:3.5-6.3 EZ. This is the cheaper of the two 'kit' options for the E-M1, and is a versatile little lens (it's weathersealed, offers a choice of manual or power zoom, and has a handy 'Macro' setting offering 0.36x magnification). Optically it's not spectacular though, and no match for the (much) more expensive M.Zuiko Digital ED 12-40mm 1:2.8 Pro option.

Olympus OM-D E-M1
Olympus OM-D E-M5
E-M1, 14mm F3.5 E-M5, 14mm F3.5
100% crop, centre 100% crop, centre
100% crop, corner 100% crop, corner

The differences are subtle here; diffraction has clearly taken a huge toll on sharpness, and no amount of clever processing can recover the blurred-away detail completely. But the E-M1 has managed to produce an impression of more detail in both the grass and the foliage of the tree, compared to the E-M5. This will likely bring some improvement to moderate-sized prints, but overall we'd still recommend avoiding apertures smaller than F11 unless extended depth if field is critical to the image.

High ISO noise and banding with the Panasonic 20mm F1.7

The Panasonic Lumix G 20mm F1.7 ASPH is one of the best-loved Micro Four Thirds lenses, for its combination of excellent image quality yet tiny size, and has recently been updated to a metal-skinned 'II' version. On the E-M5, though, it has a bad habit of inducing image banding at high ISOs, especially under low colour temperature artificial light. Sadly though these are precisely the conditions where fast primes often get used.

Olympus says the E-M1 offers improved high ISO image quality compared to the E-M5 too, so we've shot the two cameras side-by-side using the 20mm F1.7 (original version) to look at both banding and the cameras' high ISO JPEG rendition. Here we're looking at ISO 6400 and ISO 25600, using an incandescent bulb with a colour temperature around 3000K mas the light source, similar to domestic indoor lighting. We've set the cameras' Noise Filter setting to 'Off', which in general we prefer.

Olympus OM-D E-M1
Olympus OM-D E-M5
E-M1, ISO 6400 E-M5, ISO 6400
50% crops 50% crops
EM1, ISO 25600 E-M5, ISO 25600
50% crops 50% crops

You can see immediately that the E-M1 shows no sign of banding with the 20mm at all, even at ISO 25600. The overall image quality is visibly better, too, with the biggest improvement coming in colour rendition, especially in relatively desaturated areas and in the shadows. So here, certainly, the E-M1 shows a clear improvement over the older camera.

Image stabilisation

Olympus claims that the E-M1's image stabilisation is more stable at very slow shutter speeds, and our informal testing seems to bear this out. With relatively wideangle lenses we've been able to get entirely usable images at shutter speeds around 1 second, which is very unusual indeed. Of course this is going to be highly dependent on the lens - don't expect the same using a telephoto zoom - but it's impressive stuff. Below we're showing a few real-world examples to give an idea of what it can do, using a variety of lenses.

Olympus 17mm F1.8, 1/4 sec 100% crop
Olympus 17mm F1.8, 0.8 sec 100% crop
Olympus 9-18mm @12mm, 0.3 sec 100% crop
Panasonic 12-35mm F2.8 @23mm, 1/5 sec 100% crop

The 100% crops may not necessarily all be perfectly sharp, but they're not bad in the context of the shutter speeds being hand-held here. Overall the E-M1's in-body IS is doing an excellent job of keeping things steady.