Seven pairs of lenses that had roughly equivalent fields of view on the respective cameras were compared. Each camera was secured to the tripod, and the shutter was released with a remote (after waiting at least 10 seconds following mirror lock-up in the case of the A900). Image stabilization was off for the A900 (the NEX-7 lacks in-body stabilization and none of the lenses tested offered stabilization). The tripod (an old wood Zone VI) and Acratech ball head were not moved during the camera swap. An ISO of 400 and an aperture of f/8 was used on both cameras. All test images were recorded as raw files; jpegs from the NEX-7 with the initial firmware were not usable for comparison purposes.

 

The tests reported here involved shooting the same scenes with lenses of roughly equivalent fields of view: 15 mm (on NEX-7) vs. 20 mm (on A900), 25 vs. 35, 28 vs. 45, 35 vs. 50, 90 vs. 135,  135 vs. 200, and 200 vs. 280 (1.4x extender on 200). In an attempt to reduce the number of variables (of which there are obviously many), I also used the same lens on both cameras and moved the camera to adjust the field of view and tried a couple of zoom lenses on both cameras. In this latter set of tests, three alpha-mount zoom lenses (17-35, 28-135, and 70-400  [via the LAEA-1 adapter on the NEX-7]) set for equivalent fields of view on the two cameras were used. I realize the optical properties of zoom lenses change with focal length but probably less so than with two independent lenses. None of these three heavy zooms is likely to be matched with the NEX-7 in daily practice, but they offered a different aspect to the comparisons. Although the NEX-7 looks a bit silly on the 70-400 mm zoom, in some cases, it produced sharper images with this lens than did the A900."