Since handholding at 1/20 is hard at 75mm, I turned on more room lights for the ISO 3200 image, but the 6,400 image was f/5.6 and 1/40, the 12,800 was f/5.6 at 1/90, and the 25,600 was f/5.6 at 1/180. Only the 25,600 image is _not_ sharpened. The white speckles in the 12,800 image are sharpening artifacts. Note: noise reduction was applied in raw conversion in lightroom.