Nikon makes some excellent prime lenses, and the newly released 105mm is now a favourite of mine. After the 58mm, it is the second- most useful lens in my bag when I go to Africa. It is fast and its optical quality is quite magnificent.

This photograph of a black panther required precision in all I could do and then precision in all the camera could do. I shot with 1/1600th of a second, as this cat was moving so quickly toward my cage that I worried any longer shutter speed would risk blurring—and what a picture to screw up by making a lazy setting. I opened the lens wide up to F2.8m to make everything in front and behind the panther’s face out of focus. I think I had three inches of depth of field— just enough. The 45-degree early morning backlight left me with a balancing ISO of 500, which on the D850 is fine. I chose the D850 over the beast that is the D5, as I was happy to sacrifice frames per second for resolution.

That is quite a technical narrative for this photograph, but the reality is that after the word emotion, I think the next most important word for a photographer is maths. Photography may be an art long before it is a science, but maths does matter.

I look at this photograph with the dust, the composition, the backlight, and the energy and I recognize that my skills as a photographer have improved with age. I make pictures rather than take them, and through failure I have a more refined understanding of what I need to do when I go to work. I am not sure I could have made this image in 2010 or even 2016.