I had the general question floating in my mind, whether I could take my NEX3 mirrorless cam, with the basic 18-55mm kit lens, and using the unique 6-frame image-stacking mode for high ISO, actually achieve anything usable shooting ISO6400 - the main thing was whether the camera's stacking and blending algorithms could cope with the animatronic movements between the 6 frames (the algorithm has supposedly been tweaked in the newer Sony APS-C cameras to actually only stack the areas where nothing moved, avoiding any motion blur). ; Roger in particular might find this interesting, as his camera has this multistack ability. The glowing answer is: yes it can. ; And well. ; I was also shooting at the same time with my A550 and Sigma 30mm F1.4 lens wide open at ISO6400 doing normal single frame shooting - it shares the same sensor as my NEX3. ; The NEX kit lens is a slow F3.5-5.6, so it could only really pull this off at ISO6400 with the multistack feature...now that I know it works, I might try next time with a faster F1.7 lens on the NEX for even better results. ; Anyway, here we go (click on each photo for a slight enlargement and increase of quality): Shot with the NEX, ISO6400, 6-image in-camera stack, JPG mode, straight from camera: Regular ISO6400 shot from A550 with Sigma 30mm F1.4 lens at F1.6, JPG mode, straight from camera: It's partially contributed to my ability to zoom in closer to the scene with the NEX and kit lens, but even comparing full size, the noise is very much lower, as is a nice reduction in NR smearing around areas like the background...detail is a wee bit sharper too, like being able to clearly read every poster on the wall behind the characters. ; And the motion blur has indeed been avoided. Shot with the NEX, ISO6400, 6-image in-camera stack, JPG mode, straight from camera: Same scene shot with A550, standard ISO6400 single frame, at F1.6, JPG, straight from camera: Again, zoom provided some advantage to detail - here they are pretty similar overall in detail - again the NEX is a wee bit cleaner in the backgrounds, and holds a tiny bit more shadow detail - but they're much closer. ; But then you have to consider the fact that the NEX is using a kit lens nearly 3-stops slower (shot at F4.5)!! ; That is something else - 3 stops less sensitivity, and equal if not better results using the same sensor. ; This image stacking stuff is pretty nifty! Here are a couple more examples - I don't have comparative shots from the A550 for these, but they still give a good account of the image-stacking mode's quality at ISO6400, as well as the ability to handle motion. ; You know this guy moves around a ton, yet no problem for the 6-image-stacking mode to piece it together without motion blur and with extremely low noise and high detail for ISO6400: And these two move quite a bit too - here the kit lens was out to 50mm, nearly full zoom...yet noise is almost non-existent, and detail excellent: The slow lens might even provide a bit of an advantage in one respect - the depth of field isn't as shallow, making it easier to capture the scene and land focus...normally, you wouldn't want to be 3 stops slower on aperture at ISO6400, because the shutter speed would fall far too slow...but with the image-stacking mode the camera could squeeze out a 1/15 to 1/30 shutter, just at the limit for slow rides, and still deliver a nice exposure plus nearly eliminate noise while maintaining detail. If your camera has built-in image stacking, try it - it's quite something, either for high ISO use, or for HDR blending in camera. ; And it's nice to have a tiny, portable mirrorless camera either as a second body to a DSLR or to even replace it when you want to travel light, but know you can still get the same shots as the big camera in many cases!