With sufficient light but the images with the telephoto zoom 70-400 are really good. In the area of shorter focal lengths each pixel contributes to the resolution. At 400mm, the resolution is still very good. The slight CA at 400mm is eliminated by the correction in the camera (see recording with the 23 black-headed gulls). Even when shooting at ISO 400 to 800, the pictures are good, although not perfect at the pixel level. My focus: outdoor shots with a telephoto zoom at ISO 100. Since the SLT A65 (A77) is currently unbeatable.
Noise ?: For interior and dusk there are fast lenses. Then you do not need and ISO 3200. The other way around, when shooting in poorly lit interior is a calculated out for noise reduction from three shots. The pictures are not pretty, but they show more detail than I can ever see without aids. Who needs high ISO values to SLT A57 or cameras should purchase with full-frame sensor.
OLED viewfinder: For high resolution you have to work in medium to large apertures. It depends on the accuracy of the AF. The depth of field at 400mm and F5.6 is only slight. And as far as I am satisfied with the viewfinder. Because I can focus judge well, precisely because of the contrast viewfinder attaches high. And the necessary information about ISO, exposure, everything is clearly visible on the viewfinder edge. Because the viewfinder is working electronically, it can be used as an alternative to the LCD display, eg for fresh recordings to watch. This is very useful in bright outdoor light.
Macro shot with Tamron 60mm: 1: 1 shots the pixel size of 4 micrometers is actually the effective resolution limit. Objects with 0.01mm Details are to be detected. For focusing, I used MF with edge enhancement, which is a wonderful resource. Similarly, one can activate the magnifying glass function of the viewfinder, also doing very well.
Street Scenes with Tamron 17-50mm: Casual rim parties, inscriptions in the windows, everything can be seen. In contrast to the modest kit lens 18-55mm Tamron delivers excellent sharpness to the edge.
The video function delivers excellent quality with the lenses mentioned above for the HD format. The feature panoramic scene works amazingly clean.
Last: cameras with full-frame sensor like indeed concerning high ISO values have been better.. But at telephoto with the same lenses they provide no advantage to the APS-C format.