Here are some practical examples of the ISO range of the Olympus OM-D E-M1X. The camera has a Micro Four Thirds sensor. That smaller sensor provides benefits in terms of extended the focal length reach of lenses, but it also makes it harder for the to perform well in low-light situations and at higher ISOs.
Unlike some other cameras these days that feature eye-poppingly high ISOs into six figures, the E-M1X has a fairly modest range from 64 to 25600. Of that, the native ISO range--that is, the true ISO that the hardware sensor is designed to handle, is 200 to 25600. The two lowest settings--64 and 100 (or close-to equivalents) are actually in a Low extended range where software is taking over.
Here are some examples. While this probably isn't the typical type of scene that M1X shooters might want to shoot, it's one I've used with other cameras and have found that it provides a challenging test for cameras. It has smooth gradients, a lot of dark tones, sharp detail, and subtle colors. So it really tends to show up any weaknesses at particular ISOs.
Each shot here corresponds to a step in the camera's ISO range. These were all shot in RAW originally. The versions you see embedded in this page were regenerated in Lightroom from the RAW file, replacing the embedded thumbnail preview that the camera puts in the RAW file. For JPGs and JPG previews in RAW files, the camera's processing engine applies by default some noise reduction. That processing doesn't affect the underlying RAW data, so re-rendering the image bypasses the camera's built-in noise processing. But because it can be useful to see the JPG versions as well--after all, there are still many situations where it makes sense to shoot JPG--I've included a link to the original straight-out-of-camera JPG and RAW versions in the caption for each image. The RAW (.orf) versions here range from around 18MB to 25MB, while the JPG originals range from about 6.5MB to nearly 12MB.
ISO Range Sample Images Taken with the Olympus OM-D E-M1X
You can also click on each image to open a full-size version for a closer look or use the links in each caption to download the original RAW and JPG versions.
Things Worth Knowing
If you're using the Auto ISO feature, you can only go up to ISO 6400. To get higher than that, you'll need to switch to setting the ISO manually.
You can find my hands-on review of the Olympus OM-D E-M1X here.
Where to Find Them
You can find the E-M1X at B&H Photo for $2,999 for the body.