A57 and A65 are very, very similar. While the A57 is actually not as well equipped (no GPS, less MP, worse viewfinder) it was a bit higher in the ratings Augrund praised the image quality; the A65 came a bit earlier on the market and is the Sony marketing has been classified a class higher. Was priced half a year ago still a significant difference there, now you both get virtually the same price, mainly because of the fact that the A65 has become cheaper. When A57 I have around Christmastime can even observe a rise in prices. The case is the same for both, the weight from a few grams as well.
GPS I have not used. The main issues for me were therefore:
1) If the viewfinder of the A65 really that much better?
2) Is the noise of the A65 really so much worse?
3) Attach the 24 MP really so much to me as the 16 MP?
After I was able to form me by searching the internet alone no final opinion, I have both ordered and compared. In both I have very good mid-range lens 18-135 used.
My Conclusion:
1) Viewfinder
The viewfinder of the A65 is better, but you really take that true only in AB comparison. The double number of pixels makes little difference, and the seeker of the A57 dissolves sufficiently fine, and you can see detail and sharpness well. He is not as high contrast as the OLED viewfinder of the A65.
2) noise
I can confirm first of all that you can to ISO 1600 establish no real difference between the two. Only at ISO 3200 the A57 intersects visible better. But even here the differences are minimal. The A65 shoots still quite usable photos at this level. I was here too surprised at how small the topics discussed at the tests and forums differences in reality. The to-find in the forums presumption that shooting with the A65 at 12 MP less noise, however, I could not confirm. Even at reduced resolution so they intersect at ISO 3200-turvy underperformed the A57.
3) 24 MP vs. 16 MP
At low ISO values (ie good light) is the image of the A65 at high magnification slightly sharper. But that will be visible only in extreme cropping. From ISO 1600 are both back on par, ie the A65 ironed out the details then get out by the filter.
The comparison has not made my decision really easily. I again have a night sleep over it.
I bought in the end, the A57 and the following reasons:
A) A main reason for the purchase of a DSLR (yes, I know, the Alphas are DSLT) was that I can do with my standard clippers no reasonable shots in low light conditions. The children in the evening to take pictures at a school play without flash, but with Zoom does not go simply. At a party mood simple? Is not.
A good performance in low light personally is very important to me. And because the A57 is just a tad better. It is also convenient because the auto ISO range goes up to 3200. Sure, you can edit with Lightroom Raw images of the A65, so that you can see no difference in the final result. But I'm not an art photographer and do not have much time. The best possible result without digital processing provides the A57.
Of course, the greater leeway in sensitivity gives more opportunities to work with short exposure times and smaller apertures.
B) The colors have something better like in the A57. The differences are minimal and fall only with AB-comparison, but came to me before a little more natural.
C) One may me for stony, but I like the 2x digital zoom the A57. Clearly, in terms of quality brings nothing - I could zoom out the image later on your computer, but I sometimes find it pleasant, right when taking pictures to have a little more air when zooming.
Both cameras have incidentally already a great 2xZoom without much loss of quality. The A57 has a Clear-image zoom, which I do not know exactly how it works, but it brings very good results and in contrast to the A65 not only allows a Spot AF. The A65 also has a maximum zoom factor of up to 2 without loss of quality, but at the expense of resolution (2x magnification reduced to 6MP). The Zoom functionality is great for both systems and turn a 135mm lens 270mm (clear - with small drawbacks of the quality / resolution). The digital zoom allows me to zoom up to 540mm, but then with visible loss of detail.
My Recommendation:
If you want to make sophisticated pictures in normal light with highest detail resolution, should choose the A65. Since the 24 MP already bring something. Those wishing to take digital post only in an emergency and often photographed in the dark times, is better served by the A57.
Both cameras are great devices and worth their money. From me there at the A65 one point deduction, because if a camera manufacturer is located higher than another, should be reflected in the image quality.