Variable focal length in sony a6000 images with drotag cable

we are using hexacopter with pixhawk cube black,
camera- Sony A6000
drotag cable - for Geo tagging
firmware - 3.6.7
focus mode - AF-C
The problem is focal length change in every image in AF-C mode.

I always use Shutter priority mode.

which focus mode you used.
since we are using AF-C focus mode.

Regardless capture mode (iso, shutter pri. Manual etc). Locking focus on Sony’s with a varyfocal lens is a mesh. You may try focus on a similar distance before flight or rotate the lens slightly left from the infinity, the use some tape to secure it.

My opinion. Select an appropriate fixed focal length lens. Sigma 19, Sony 20 or Sony 35 for APS c are superb.

sony alpha 6000 by default 16mm focal length in every image,but i still facing a problem focal length change in every image(sony a6000 with drotag cable).
please give me a solution regarding this.

Kindly elaborate a bit, or upload some photos from your setup and/or some taken images.

Assuming you have the stock 16-50mm lens, most probably you face the problems I describe in me previous post.
If you have a 16mm fixed focal length lens (improbably), then you might confuse the focus with focal length. Whatever the Cable is from it doesn’t affect the camera, beside IS and AS.