Sony FE 28-70 mm f/2 GM
10. Autofocus and focus breathing
Autofocus
According to the producer as many as four XD linear motors (XD stands for extreme dynamic) and the newest algorithm are responsible for an efficient performance of the focusing mechanism. We checked these declarations by attaching the Sony FE 28-70 mm f/2 GM to the Sony A7R IIIa and the Sony A7R V cameras.In both cases the autofocus performance is noiseless and quick. The lens allows you to set the focus already from 38 cm and, despite the fact that it has to cover a significant range, its focusing and confirming the right position takes just 0.2-0.3 of a second. It's a sensational result and, what's important, not especially depending on the focal length you apply and lighting conditions. You get here a performance worth a top-of-the-range professional lens. A round of applause!
A similar situation can be observed when it comes to accuracy. We didn't notice here any problems no matter what camera was used and whether we worked in our studio or outdoors.
The tested lens didn't show any front or back focus tendencies no matter what body we attached to it.
Please Support UsIf you enjoy our reviews and articles, and you want us to continue our work please, support our website by donating through PayPal. The funds are going to be used for paying our editorial team, renting servers, and equipping our testing studio; only that way we will be able to continue providing you interesting content for free. |
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
| A7R IIIa, 50 mm, f/2.0 |
 |
| A7R IIIa, 70 mm, f/2.0 |
 |
| A7R V, 50 mm, f/2.0 |
 |
| A7R V, 70 mm, f/2.0 |
 |
Focus breathing
Focus breathing tests show reframing images as you oversharp them. We conduct the test by manually passing from the minimum focusing distance to infinity with the aperture stopped down; then we check how the field of view of the lens changed as a result.A frame change ranging from 0 to 5% we consider to be low. Between 5 and 10% you can speak about medium levels. Usually such values constitute also the maximum efficiency level of any breathing compensation algorithms, present in some bodies. Between 10 and 15% focus breathing is high, above 15% its level can be called very high.
The test video of the Sony lens is presented below:
