If you are shooting at max zoom with the P1000 you are better off doing manual focus. AF is not at all reliable at longer focal lengths due to low contrast and a lack of light, as P&Struefan pointed out.
In poor light you are going to get a lot of noise, which will contribute to the lack of apparent resolution, plus, at those long focal lengths atmospheric distortions will muddy up any edge. All of that combined will result in blurry images. You need good light to have decent images with the camera.
Last edited by Tugela; 01-14-2019 at 05:11 PM.