The Sony NEX-7 has the same sensor as the Sony A77 and Sony A65, but it’s not a single-lens translucent (SLT) camera — that is, it doesn’t have a partially-translucent mirror — and that makes all the difference, because it doesn’t have to contend with mirror-related light loss. Let’s take a look at how the NEX-7 fares against different kinds of cameras, starting with its Sony SLT relatives.
Comparing the Sony SLT A77 vs Sony SLT A65 vs Sony NEX-7:
So it is not surprising to see the A65 come in lower (at 74 points) than these other two cameras, given that it has no ISO 50 (advantage: A77) and a translucent mirror (advantage: NEX-7).
Comparing the Sony NEX-7 vs Pentax K5 vs Nikon D7000:
We applaud the Sony for succeeding in matching its competitors’ image quality scores. This was not a foregone conclusion despite having a significantly higher resolution than either the Pentax and the Nikon, because of its smaller pixel pitch on a sensor of nearly identical surface size.
What’s more, the NEX-7’s minimum ISO of only 100 put it at a disadvantage compared to the K5’s ISO 80, and indeed the NEX-7’s low-light results are noticeably lower than its competitors’ (1016 points vs 1162 and 1165, respectively).
Comparing the Sony NEX-7 vs Olympus PEN EP3 vs Nikon 1 V1:
No surprises here: the NEX-7 is by far and away the leader with a DxOMark score of 81 points — 30 points ahead of the Olympus and 27 points ahead of the Nikon. All these cameras are ergonomically similar, compact and lightweight, but the NEX-7’s larger sensor gives it a clear advantage over its rivals.
In conclusion, the NEX-7 is a success in terms of sensor image quality. In light of its current results, it’s hard to resist thinking about the kinds of scores a future “NEX-X” could achieve were it to add ISO 50 to its mirror-free advantage…. and about the kind of score a full-frame DSLR would achieve with the same sensor technology as the Sony NEX 7 or Sony A77.