I took the photo from an open top vehicle equipped with a spotlight that is shone to either side of the animal which at no time is used to any advantage for either predator or prey. And never shone directly in their eyes.
I use RRS off camera flash bracket, with a Better Beamer as shown below. IMO you can never have the bracket high enough and at times I have got my wife to hold the flash some metres away to get the right lighting!
You put it on the flash, set the flash zoom (if it has one) to about 50 mm, and shoot away. TTL exposure works exactly as it does without a 'beamer attached.I always do a test shot to confirm it is pointing where I expect.
50mm is the recommended setting to have the manual zoom set to on your flash.You can go down to as low as 24 mm on the flash and this concentrates the beam so that it will go even further, but the trade of is of course that the beam is narrower and you need to make sure it is aligned correctly.
The key to using the beamer is repeatability, ie. putting it on the same way each time.
I marked my flash with textra colour where the velcro should go
and put the unit on the same way each time and know how it should be sitting. Initially I took it on and off a few times, taking shots each time to confirm that I put it back on right and that calibration is correct.
The easiest way to calibrate is to find a wall or something around 10-20 m away and take a shot of it with the beamer on the camera, adjusting the position of the velcro and or any flash brackets until the whole frame is lit evenly.
I use 24mm for this check as the beam is at its narrowest.
If you get it right here, then you have plenty of margin for error @ 50mm.
Take the flash off the camera and remove the beamer.
replacing it and repeating the test, that way you know you can put the unit on the same way, even then, every so often you should check the calibration just in case I havent lulled into bad practice.