Optical device with improved autofocus performance and method related thereto

An optical device with improved autofocus performance comprising:

• a housing,
• at least one lens unit,
• a storing medium for storing an image of a target subject,
• a focusing unit using at least one focus detector for focusing a given image plane of the target subject onto the optical device,
• the focusing unit comprising a focus lock for locking a focus distance (d1) between the optical device and the given focus plane in a first camera position,
• and a shutter release for releasing a shutter in a second camera position following a reorientation of the optical device for achieving the desired framing of the image,
• wherein the focusing unit comprises a focus distance correction unit comprising a sensor for sensing a distance vector being parallel to the focus plane after reorientation between the first camera position and the second camera position,
• a calculator for calculating a focus correction value (de) from the distance vector,
• an adder for addition of the focus correction value (de) to the locked focus distance (d1),
• wherein the sensor is for obtaining the distance (d2) between a center of the focus plane after reorientation and a center of the given focus plane in which the focus is locked and wherein said device comprises an analyzer for analyzing the movement of the target subject within a given image framing, wherein the storing medium comprises an image sensor and analysis of movement of the target subject is based on raw frames which are continuously received from and downscaled in the image sensor after focus lock.