Designing a Macro Bracket

I’m starting to think about my macro rig for 2010, now the weather’s getting nice enough to go outside again. I have a good general idea of what I want to do, given my budget constraints and what worked or didn’t work last year.

(In my head, what I call the “rig” is everything involved: the camera, the lens and any tubes/rings/diopters that get you to macro magnifications, the flash(es) and related modifiers and cords, and the bracket that ties it all together.)

If you’re just thinking about a macro bracket for the first time, it’s a pretty simple build. It’s basically the part of the rig that connects everything: usually a long flat plate that screws into the camera’s tripod mount, with some sort of mount for the flash on the other end. The value comes from getting the flash away from the lens axis, to add depth and texture to the subject. The trade-off you’re trying to minimize is the added weight of an off-axis light, and the hand-shake and fatigue that it introduces.

Over the next few weeks I’ll build the thing, but here are my general parameters that I’m starting from:

Ergonomics
It has to have good balance. This is key. Wrist and finger strain are the number one reasons I’ll pack it in before I get the shots I want. I picked up a Zeikos battery grip, partly to get my pinky in on the action and partly to move the center of gravity closer to my hand. I think I might get a hand strap as well — that actually would help a lot, since it would take a lot of work away from the fingers.

Even with good balance, it still has to be relatively lightweight. I think a plastic plate will work better than the stainless steel ones I’ve been using. I could also drill my own mounting holes very easily. The trick would be finding one that’s strong and inflexible.

Another problem with the stainless steel plate is that they scratch the camera body. I’ve already covered the one from last year with black duct tape — it looks pretty good.

The bracket can’t slip. The weight of the speedlight provides a lot of torque when it’s moving, and it’ll unscrew the plate from the camera and the flash mount. Part of my problem last year was using flat-head screws on plates with beveled mounting holes, or bevel-headed screws on flat mounting holes. This wasn’t by choice: I was using pre-drilled plates from the hardware store and had to work with what they had. I tried to counter this with rubber grip tape, but that costs a few turns of the screw into the tripod mount — again, insecure.

Utility
The bracket should hold the flash in a good position: about 10 o’clock or so. This hasn’t been a big problem for me. The mount for the flash should be adjustable; I’ve been using a mini-ballhead, and may replace it with a cheap geared umbrella adapter for more stability and fine control. It would be nice if the distance from the camera could be adjusted, too, and I’ll be thinking about that when I look at brackets.

In a perfect world, the bracket and flash mount would be so secure that I could shoot in portrait orientation without having anything slip or sag. The challenge here is that the weight of the flash will often turn the mounting screws counter-clockwise…

The rig should include a diffuser for the flash, basically a mini-softbox. I’ve just built a new one that I have high hopes for, out of a large yogurt container and some translucent vellum paper. This will get its own post once I’ve really seen how it works, but the key is getting a large apparent size for the light in a design that stays securely in the flash head. If I end up using an umbrella adapter, I may consider building something like a small umbrella.

The flash should be close enough and strong enough to use a low power level – ideally around 1/4 or 1/16 at ISO 100, f/8-f/14. This is to get a very fast flash pulse, which in macro lighting acts as the shutter speed — the faster the flash, the better it freezes the image. With my 40D, I’m willing to go up to ISO 200, and in fact shot there all last summer.

Value
The DIY parts of the rig should be no more expensive than a store-bought solution, and it should be as reliable as one of equivalent cost.

Off-the-shelf components should be inexpensive. If they’re not, they should be of very good quality and should be usable in non-macro photography.

It should be stable and sturdy enough that I won’t need to tweak the design or replace parts over the summer.

The parts, especially the plate, should be made of easily available materials. I don’t want to get something custom milled at ridiculous cost. Ideally something from the hardware store that I can cut or drill myself. But no false economy, either: I don’t want to pay half-price for a half-assed solution.

Part 2: More thoughts on the bracket.
Part 3: Bracket solved.