Sunday, January 27, 2013

Right Angle Flash Mount For Photek Softlighter

In an earlier post, I described something I named the Black Plastic Thingy. Its purpose was to allow the positioning a speed light closer to the axis of an umbrella-based light modifier, specifically the Photek Softlighter. The BPT did just that, but was not very secure. This shortcoming left room for further investigation. As I mentioned in the earlier post, the trick is getting the flash as close to the umbrella shaft as possible.

One item that caught my eye was the Lastolite Brolly Grip. This device was a marriage of an umbrella bracket to a convenient carrying handle. It was unusual because it incorporated a special cold shoe that allowed for on-axis positioning of the speed light. Unfortunately, because it was designed to be hand held, there were no provisions for pitch control. I was tempted to purchase one, but instead decided to make something that would reposition the flash using bits and pieces I already had.

W. J. Wescott has introduced a number of reasonably priced light modifiers. Last year I purchased a Halo, which was essentially a shoot-through umbrella with a conical shroud that prevented flare from light back-splash. The big problem was mounting a speed light on the inside of the Halo. It utilizes a conventional umbrella bracket that positioned the flash in an upright position, forcing the placement of speedlight very close to the umbrella's inner surface. If I could mount a speed light along the umbrella axis, I would have more freedom to position the speed light further away from the diffusion surface. It just so happened that many of the Wescott light modifiers come with their own umbrella bracket with an integral cold shoe that employs a clamping action to secure the speed light foot. I decided to see if I could use clamping action to hold a right-angle bracket firmly in place. I would then add a second cold shoe to hold the speedlight.

First, I measured the width of the steel foot of a Nikon SB-800 and found that it was exactly 3/4 inches wide. I checked with a local hardware store and found some galvanized, right angle brackets with 3” arms made from 3/4 inch flat stock (Ace Hardware Corner Brace, Inside L). This would give me the right-angle repositioning I was looking for. But when I tried clamping it in the cold shoe's jaws, the bracket was too thick. This was quickly solved by filing a 45° bevel on the edges of the bracket to match those on the cold shoe.

Let’s talk about files. They come in different lengths, and different coarseness of cut. They range from bastard (coarsest) through second cut, to dead smooth (finest). My first cuts were made with a 12-inch bastard and were finished with a 10 inch dead smooth file. Remember that files only cut on the forward stroke. Do not allow the file to drag over the work surface during the backstroke or you will dull the teeth. Files should be cleaned with a special wire brush called a file card. A clean file allows its teeth to cut to their full depth, and for the chips to fall away while cutting. Best results will be achieved when your project is clamped in a vice. This minimizes "chatter" and will allow you to use both hands when using the file. While you have the file in your hand, lightly file all of the rough edges on the bracket, or anything else that might snag your umbrella’s fabric cover. Incidentally, I'm not particularly proud of my file work, but in this case, good enough is.

You can see that the bevels mesh nicely with the jaws of a clamp-type cold shoe. When tightened, I found the junction quite stable. The additional contact surface provided by the bevel made the difference. If you extend the bevel toward the "elbow", you can get some fore-and-aft adjustment, should you ever need it.

Once the bevels have been cut, you are pretty much done with the project. You can use the existing holes to mount the cold shoe using a ¼ x 20 thumbscrew. You can drill additional quarter-inch holes to provide additional positions for your mounting shoe. Depending on the type of cold shoe you use, you might find that the hole closest to the corner of the bracket does not provide enough clearance when the speedlight is installed. But if you’re using a clamp type shoe, you may be able to back the flash foot out slightly to gain some clearance.
Now if you’re using a conventional umbrella or a Photek Softlighter it is easy to establish a line-of-site relationship for optically triggering your flash (Nikon CLS or SU-4) because the sensor eye is on the "outside". But when  using the Halo,the flash is mounted on the inside and you will need to make other arrangements to trigger the flash. You could always use an extension cable, but with the availability of inexpensive radio trigger devices, you can well afford the luxury of wireless flash work. You get what you pay for, because unless you go with the more expensive Radio Poppers of the Pocket Wizard Flex series, you’ll lose TTL control over your flash. More on that later.

A final note on clamping cold shoes. I prefer the Stroboframe Shoe for the better build quality. I must admit that cheaper "Made In China" alternatives are out there, and I'm sure they will suffice. I have had some of Chinese versions strip their threads. You get what you pay for, I guess.