Determining the Guide Number of an LED

David Gibson · Post by **David Gibson** » Wed 04 Mar 2015 12:40

CREG journal 89 - published today - includes an article by myself on Determining the Photographic Guide Number of an LED. It does this from a theoretical point-of-view and as a starting point for anyone who wants to design an LED flashgun for cave photography. However, what is missing is the practical angle - it would be good if someone could, by means of some carefully-controlled practical tests, establish the guide numbers of some existing LED lamps. Please post your results here!

There is a discussion on LED lamps currently taking place on the ukcaving forum, where I have posted a message.