The automobile rig market has exploded recently thanks to a formula of relatively cheap accessories that allow anyone with the patience to capture images simulating tremendous speed. The off-the-shelf components are all produced by Manfrotto and include (3) Super Clamps, (2) Avenger F1100 6" suction cups (optionally you can get the model with built-in swivel pins for more placement flexability) and a boom. Added to this recipe, many choose to include a Manfrotto 244(N) Magic Arm attached at the end of the boom fitted with a ball head of their choice to add a little freedom when placing the camera and perspective. Deciding on the boom is usually the tricky part. Does one go down to Home Depot and pick up steel conduit piping? That solution is very economical, but the drawbacks are significant. A 10' pole is not easy to transport, is heavy for its size, and is not very long (you'll want longer for the dramatic wide-angle shots that incorporate more background). Another solution would be to make or have made a 15' to 20' segmented aluminum boom. Aluminum resists vibration better and is lighter for a given size, this would allow you to go larger diameter for added strength and reliability without adding appreciably more weight. But having a boom made can be a bother in itself. Ordering bulk aluminum pipe and hiring a machine shop to cut and thread the pipe are steps many would like to avoid, opting to buy something that's turnkey and hassle free.
If that's you then Rig-Pro has your product. Rig-Pro's booms are 1.75" diameter aluminum pipes with threaded couplers and now ship with thread protectors. Additional 60" threaded segments, for converting to a 20' boom, are also available. Contact Rig-Pro for a price quote.
You'll notice immediately how sturdy the boom is. Coming over from conduit piping I was struck at how much more massive the Rig-Pro boom is yet did not seem to add a significant amount of weight. Steel conduit piping feels flimsy by comparison.
Rig-Pro booms are die-cut threaded. This may exacerbate a problem further down the line as aluminum galling will eventually wear much of the initial thread away, creating more play at the mating points. This friction effect is why we photographers pay extra to have brass filters. You can minimize this by using a lubricant, such as graphite powder, readily available at most hobby shops or online. This will help preserve those delicate threads. It should be noted that had these pipes been threaded with a lathe, producing a smoother thread face, you would still have to deal with the negative effects of galling. However, die cutting is a rougher cut making the effect more pronounced and accelerating the wear. Regardless, with diligent and judicious use of graphite lubricant, your threads should remain quite useable for many years to come.
By attaching the suction cups to the vehicle, attaching the Super Clamps to the cups, placing the boom into the Super Clamps, and the camera at the end of the boom you have assembled a proper automobile rig. Try and keep the shutter speed in the 2-3 second range to get the sharpest subject while still having a good amount of background blurring. Midday use will no doubt require the use of neutral density filters to keep the shutter speed slow. Consider screw-in type ND filters for this, preferably those made by B+W. I keep a 3-stop and a 6-stop in my bag and those can cover just about anything.
I usually have some poor schlub push the car and another steer while I walk beside the camera firing the shutter and helping to support the camera and boom weight. Also, by supporting the boom weight as we roll I can do what I can to minimize bounce by steadying the pole with my hand as it starts to dance. Conduit pipe can really wobble whereas the Rig-Pro boom is not nearly as bad. In fact, it's very manageable and a significant upgrade where boom movement is concerned.
Here I tested the Rig-Pro boom on a dirt road. The bumps and undulations of this terrain make taking rig shots an exercise in patience, but the Rig-Pro did the job and I got the above image on the first take! I'm confident I could not have taken a picture as sharp using my older steel conduit pipe so easily, the bounce would have just been too much. That's not to say it could not be done with conduit piping, it would have just taken longer.
Something you may want to consider - the longer the suction cups stay active and under load on the vehicle the higher the chance of doing damage to the paint or worse. Here's a good rundown of the pitfalls using suction cups to secure a boom onto a vehicle. Suction cups can cause pressure rings, orange peel effect, or outright warp body panels if left on for too long. Anything that allows you to get the shot quicker is a boon with this type of photography. In this instance the Rig-Pro boom made what could have required several exposures to get right take only a short amount of time, relieving stress on me, the vehicle's owner and the vehicle's paint. That is a benefit to the product not to be discounted!
Next, I tried the Rig-Pro boom on the streets of Houston. Houston was built on a swamp, so this means that the streets suffer all manner of support failure as evidenced by the multitude of patching, potholes, and dips. In short, one could describe Houston's streets as "not smooth." The Rig-Pro boom again performed exceptionally. Bounce was well controlled and I was able to get something useable within 15 minutes of the suction cups being attached to the car.
I would rather the threads to have been cut with a lathe and for the segments to bottom out against each other instead at the coupler, but that aside I highly recommend the Rig-Pro as a boom solution. The portability of segmented pipes is a godsend after schlepping an unruly 10' conduit pipe. You can't understate the convenience of being able to put 15' to 20' of quality pipe in your trunk. (Gratuitous: that's what she said) Also, the included thread protectors are genius. Aluminum threads are delicate and after banging around for a bit it would be easy to bend or crush them. Don't forget to check out graphite powder to help protect those threads.
My search for a boom is over.