I shot my granddaughter's fifth birthday party this weekend using the E-M5 + 12-35/2.8. Given a bunch of 5 year olds running around in a gym, and the lousy light, I decided to let the ISO float as high as 1600 to try and keep the shutter speed high enough that the pictures would have an acceptable level of motion blur. As you would expect, the aperture was pegged at 2.8 for the entire (exhausting) 90 minutes. The shutter speed for the keepers ranged from 1/60 to 1/180, with 1/60 being about 65%; the ISO from 640 to 1600 with 800/1000 accounting for about 60% (one at ISO 3200). I processed the raw files using LR5, and made my best judgements about the correct balance of sharpening, noise reduction, clarity, etc. Flash was used only occasionally, as the kids were running around in a large space that my flash wouldn't cover anyway. Here is my assessment of the sensor performance: - for an uncropped image, ISO 1000 gave good'nuff results for web posting (in my case, Flickr). As soon as you crop by even 20%, noise starts to be visible. - Unsurprisingly, ISO 1600 was a bit worse. But for modest crops, the images are still useable. - ISO 640 and 800 images could withstand a pretty hefty crop - half the pixels or even a bit more - and still have good quality for the web or an iPad. I should add that even for the worst of the keepers - ISO 1600, 1/60s - my wife thought the images lovely. Of course, she's biased by her love for the cute grandkids, but she is a reasonably critical viewer. My takeaways: - getting good shots under ridiculous conditions is possible with these cameras. I mean really - shooting at upwards of ISO 1600 with good color and crappy light - and getting pictures that are fit for purpose is pretty amazing. - Light quality also makes a difference. The one ISO 3200 shot was at home under LED high hats, and needed much less processing that the 1600s under the (who knows what) in the gym. - Careful framing and FoV selection can make a big difference. Cropping the images by half increases the noise risk significantly. As is often the case, I went into the initial edits feeling pretty bad about the outcome and only selected about 15% of the images for "display" to the family. But I left after a couple of hours PP feeling much better about having created a great record of an excited 5 year old enjoying her party.