We had a visiting speaker at Badby Photo club, Glyn Dewis, who is an excellent photographer, Image Retoucher and inspiration. One of the things he demonstrated was what he called his Invisible Black Background (IBB), this is a way of pretending that you have an expensive studio setup and you can use the technique anywhere even outside on a sunny day.
This technique involves fooling the camera and relying totally on the light generated from a Flash gun to produce the image.
The first step is to setup your camera to use MANUAL exposure mode, this often terrifies people and harks back to the old days when all cameras were manual, I remember it well but don't miss it one bit, and no I am not that old :)
Once in manual mode you setup the camera to a shutter speed equal to its Flash sync speed, in the case of a Canon this is normally 1/200 second, then you adjust the ISO and Aperture so that when you take a picture you only get a completely black image, i.e. you under expose. Keep checking the review screen on your camera and the histogram to check it is completely black.
In my case the ISO was 100 (a good starting point for the best image quality) and an aperture of f9. This will depend on the available lighting, this image was taken inside but on a very sunny day.
The next step is to setup the flash, the key is to use "Off Camera Flash" where the flash gun is positioned to the side of your model giving the image a more studio feel. I used a simple flash gun not expensive studio lighting! To have the flash off camera you need to be able to still trigger the flash by either using a flash sync cable connected between your camera and the flash, or a set of remote triggers which aren't very expensive.
Set the flash to manual mode and start off with a low power e.g. 1/32 and then slowly increase this until you receive the image you require, also try moving the flash further away from the model or closer. as you can see this is very much a case of trial and error, and you do need a patient model, and possibly a helper to hold the flash, so Border Collies are ideal :) You can use a reflector on the dark side of the model to give some detail to both sides of their face.
The post processing I did on this image of Jethro was using Lightroom, and the Nik Silver Efex plugin for the Black and White conversion.
Please spend some time to visit Glyn's website https://www.glyndewis.com/ as he has lots of interesting techniques and videos etc. Here is a link to his YouTube video which explains this technique in much more detail... https://www.youtube.com/watch?v=FO9Zy8m3cxw