I have written a number of times before about background control, recently and less recently. It is one of the things that can make a big difference to an image and consciously controlling backgrounds is one of the steps to rapidly improve your images. I shot these following images of the same Little Black Shag on the same perch to illustrate the point for a workshop.

The images in the above gallery are the full frame captures to give context. By changing height and angle I could achieve a number of different backgrounds on the bird. This next gallery shows the quickly edited files to show the range of backgrounds achievable. The first image in the top gallery was my initial image including out of focus foreground elements before exploring the other options to illustrate the point and remains my favourite from the series.

My priority with backgrounds is to eliminate anything that could draw the eye and distract from the the subject. In these examples all the backgrounds are quite distant and smooth apart from the pure blue background which has an out of focus gull as a pale blob just above the bill of the shag. I managed to minimise this with masked contrast adjustments and could eliminate with some cloning if needed. If it had been a fixed object a small movement could have hidden it behind the shag.

Photos with Nikon Z9 and Nikkor Z 400mm f4.5 CR S and 1.4x teleconverter.