In my hands-on workshop “The Magic of Umbrellas” one of the topics I talk about is size and it’s not just the size of the umbrella’s fabric that matters, it’s also a question about the diameter of the umbrella’s shaft. And while that may not seem significant, shaft size can affect the umbrellas you may already own and any lighting system you may be planning on purchasing.
First a history lesson: Back in the day, the de facto standard umbrella shaft measured 3/8-inch or approximately 10mm because that was the size of the shaft used by the Larson Reflectasol which was widely used by many photographers, including Mary and I. The first umbrellas and reflectors that we purchased for our then-new studio were from Larson Enterprises.
Nothing last forever and over time most umbrella and lighting equipment standardized on 8mm for the shaft size. But some people just have to do things their own way and one European manufacturer decided to use a spring loaded shaft that would accept a 7mm umbrella shaft and then some, but not all, European manufacturers decided to follow suit. Now, all those 8mm umbrellas you had wouldn’t fit these lights. Or would they.
The umbrella slot in some European lamp heads or monolights is actually larger than 7mm because there had to be room for the spring-loaded clip and occasionally you could push in an umbrella with an 8mm shaft onto the light head. FJ Westcott who’s been making all kinds of umbrellas for 100 years decided one way to make a more or less universal solution was to use a tapered 7mm umbrella tip on their 8mm umbrellas that would let you push past the clip and fit these Euro-spec lights.
In writing lighting equipment tests for Shutterbug magazine, I usually provide technical specifications and while most users are concerned about power output and recycle time, I think that umbrella shaft size is important too and will be including this bit of information in all future lighting product reviews.