Some interesting results here.
I firstly compared the Sony a77, Sony NEX-5n and the Samsung NX200 using the same lens. My Sony a-mount 30mm f/2.8 macro lens, which via adapters I can use on all three cameras. I used an aperture of f/8, and three different ISO settings 100, 800 and 3200. All were processed identically in Capture One from raw. In the first version of each test the files are kept at their relative sizes, in the second version I downsized both the a77 and NX200 files to the same size as the NEX-5n files.
As usual for a large high-res version, click on the image > flickr > Actions > View all sizes > Original.
ISO 100
ISO 800
ISO 3200
Since the tests were carried out using the translucent mirror technology in the a77 and the 5n adapter, the Samsung has faster shutter speeds for all images.
The second test was carried out using the kit lenses for each system. I used ISO 100. f/8 and a 35mm focal length.
Again the first is with the files at their relative sizes and the second with the a77 and NX200 files being downsized to the same size as the NEX-5n.
I will let you you decide for yourselves what the results indicate, but one thing struck me straightaway. That is just how much impact the Samsung kit lens is having on the impressive files I'm seeing from the NX200. I noticed yesterday when I was looking at the results from the Sony lenses I was using that they didn't have the same crispness that I was getting off the Samsung 18-55mm kit lens. That seems to be case here also.
In terms of any kind of conclusions, it does seem that the NEX-5n sensor lives up to its reputation as being very impressive indeed. It was interesting that the NX200 files seem to be better at higher ISO's than the a77 files. Indeed the a77 files seem to be pretty much the worst overall. What this means for the NEX-7 which uses the same unit is open to question. Obviously no SLT means that all shutter speeds will be "shifted down" about 1/2 stop, which will improve the low light performance and it remains to be seen as to whether the 24MP sensor will be exactly the same as the one in the a77, or whether it has been "tweaked" in the cameras software.
To be honest at low ISO's all of these results from the three cameras are spectacularly good, and all are capable of huge reproductions. However since this is a Samsung NX200 review, it does show once again just how good this sensor is. It also indicates that Samsung know how how to design and build a kit lens as well.