YeoPhotoGroup by Keith Robins

Make a reflector from a Walkers crisp packet.
A small reflector which fits most camera bags can be modified from a Walkers crisp packet. Turn it inside out and simply put your hand inside to bounce light back into the face for a portrait shot like this one taken by my friend Dave Thomas. Dave is new to strobists methods but he's keen to learn and emailed me these two shots taken during a field trip with MidSomerset camera club.
My crisp packet has the lid of a margarine container inside to stiffen it. Okay, so it could be larger, like for instance using a family sized crisp packet, but I just happened to have the smaller one in my pocket.
Holding a flashgun at arms length is pretty standard for me and is something I've done for 30 years, even before I took up cave photography. Look on it as being similar to using a fog light to increase the 3D effect and give more texture. It probably stems from not having a hotshoe on one of my cameras as a youngster. Yes, I've been involved with photography since 1964!
I'm holding a Vivitar 285HV in these shots which is set on 1/16th flash power resulting in an aperture of f11.
To make the sky appear darker than it actually was Dave increased the shutter speed to 1/200th of a second and kept the ISO at 100. He could have used a speed of 1/30th and still got an acceptable shot and although the sky would then be a lot lighter it would still result in a good picture with my face being expose exactly like is is at 1/200th.
Some club members are finding it difficult to grasp the techniques involved with using a flashgun when there is also available light present, whether it's daylight or tungsten floodlighting. The main thing to remember is that your shutter speed controls the available light - while the aperture controls the flash intensity.
In all other lighting situations if you lower the shutter speed it is necessary to increase the aperture - as if the two controls are holding hands. However, bring a flash into the equation, along with a secondary source of illumination, and the two are free to lead completely separate lives, leaving you in total control!!
Aperture = flash control.
Shutter speed = daylight control.
And don't forget that although manual settings over-rule these two obvious settings, do make sure your camera hasn't accidentally gne into Auto ISO settings, which will spoil everything you're trying to achieve.