Today I did some tests with the two lens adapters Sony LA-EA2 and Sony LA-EA4, which can be used to adapt a lens with a Sony A-mount to a camera with an Sony E-mount. In another article I already compared looks and weigth of the two adapters. In this article I focus on the different image crops when you use the two adapters on a full frame camera with E-mount. I used a Sony ILCE-7 for my tests. On a Sony ILCE-7r the crops are the same, but you get a higher pixel count.
I only tested the Sony 70-200/2.8 (SAL70200G) at 200mm. I used the lens collar of the lens to attach it to a tripod. The lens, the tripod and the subject were not moved after that.
The first image shows the result when using the LA-EA4. The resulting image is the full resolution of the sensor.
For the second image I only exchanged the LA-EA4 with the older LA-EA2. For this image I used the following configuration of the camera: Menu → Custom Settings (gear icon) → 5 → APS-C Size Capture → Off. You can clearly see the shading of the LA-EA2 on the sensor. The maximum manual crop is marked with the green rectangle.
For the next image I only changed one setting in the camera: Menu → Custom Settings (gear icon) → 5 → APS-C Size Capture → On. The resulting image showed an even larger crop than the second image but no shading of the adapter. In postprocessing I superpositioned the two images to be able to mark the camera crop in the second image. This is the result.
In the last image I used the first taken picture and marked the three different crops. The red marker is the LA-EA4, the green marker is the LA-EA2 with maximum manual crop and the blue marker is LA-EA2 with cropping enabled in camera.
The maximum manual crop (which is equivalent to the unshaded area of the sensor) will differ when you use a different lens. And it also differs with different focal lengths of a zoom lens. But this needs some more testing.