Archive 2013 · Good medium-sized boom arm?

Cableaddict
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p.1 #1 · Good medium-sized boom arm?

I did a search, and this thread in the archives is pretty much what I want to discuss:
https://www.fredmiranda.com/forum/topic/1002798

- but it's locked so I'm starting a new one
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I currently only use speedlights, but I'm pretty sure I want to switch to strobes next year, even for location shooting. I will most likely get the AB Einsteins, or something similar. I would also be using various softboxes, and a radio system, which all adds weight.

I recently purchased three Avenger A0040B's, thinking these would be beefy enough for anything I'd ever throw at them. They probably will be, but now it looks like I'm cutting it close, so I need some advice before getting booms. I have two problems.

1: I don't know how much all that stuff I'll be mounting actually weighs. Strobe, softbox, radio receiver, counterweight, and probably an A-700 drop-pin which adds another 1.5 lbs.

2: I don't know how accurate the manufacturer's weight-capacity ratings are. I assume those from top-brands are conservative.
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OK, so I'm looking at the following options, and would welcome comments / suggestions:

# Avenger D600CB Mini Boom (Black) $122 - collapses to 46"
- Max load 15.4 lbs weight: 8 lbs
- I don't understand how this mounts onto the stand.

Photoflex LS-BOOM Adjustable Boom Arm, 5' - 6'7" $133
- max load 10 lbs. weight: 6 lbs
- separates to 3 pieces, and it looks like I can use only 2, for less weight & 5' length
- drops right onto the stand's top pin.
- I'm leaning towards this one right now.

Matthews Mini Matth Boom - Black $140
- Max load only 8 lbs weight: 7.5 lbs
- this has the worst weight-to-capacity ratio, but only if such ratings are dead-accurate. (unlikely)

The other option is to just get the Avenger D520B arm, as I only need a little bit of angle for my lights. The 520B only weighs 3.5 lbs, so there's more stand-capacity left for my strobes, but these arms do not have their own weight-capacity listed. DOES ANYONE KNOW WHAT THEY CAN HOLD?
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OTHER QUESTIONS:

1: I'd love to have the 15.4 lb capacity of the Avaenger mini-boom, but going by all the specs, that capacity is wasted as the stands won't support it. (with all the additional loads)
Is the 20 lb capacity-limit of my stands for real? I can support my entire body on the things, and they don't bend or collapse, so I have a hard time understanding this.

2: With any of these, is the weight-limit set by the arm itself, or by the grip/clamp? If the latter, (assuming I get even beefier stands) would it help to change to grip to the all-metal, toothed, Avenger D200?

3: With really large softboxes, say something like an octa, would I even need a boom, or would I just hang / angle it from the stand? If the latter, would my current 20 lb capacity be enough?

Oct 14, 2013 at 08:30 PM

Sheldon N
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p.1 #2 · Good medium-sized boom arm?

I see a lot of my comments are in the prior thread, but I'll chime in again.

Of your three booms, I'd choose the Avenger D600. I think your stands will hold up fine to the weight. I used a Manfrotto 007BUAC with my Avenger D600, so you could check the spec comparisons with your stand if you'd like. The question about stand "load" is more of a question of how brave you are to hoist something large and off axis up in the air, and whether there is any wind.

The Avenger boom mounts to the top baby pin on your light stand, just like any other fixture. The clamp and arm are extremely sturdy and the clamp of the D600 can lock down VERY tight, just as good as a grip head. If you balance the load with a counterweight on the hook (as you should be doing to keep the stand stable) there's very little load on the clamp. Once you've got a counterweight balancing the load is very easy. Then it's just a question of how much total weight is on the stand, relative to how high you want to get it. It's more about the bending twisting force that can be put on a stand by a big long heavy lever. The weight limit isn't really about the boom at all (at least not with the D600), its about the stand.

The big question is whether you need a boom at all. The only time you need a boom is to move the light stand out of the way while having the fixture above and close to the subject. I've found that I almost never need a boom on location, most everything can be accomplished with an off axis light stand out of the frame.

Right now my go to stand/boom is an Avenger A4039CS combo stand/boom. It's on par with the D600 for boom sturdiness, but also does excellent as a heavy stand with the boom retracted. I've hung a 7 foot octa off it, but only indoors. On location it's more about having a strong stand with a heavy/stable base. It's not light, but it's easier to carry around than a two piece boom/stand combo. I've also used my 7 foot Octa on location with a smaller Avenger A635B stand (no wind), so you'd certainly be fine with your current stands and larger modifiers if you decided to go without a boom. If you wanted both a boom and a stable stand for big modifiers even in wind, then something like the A4039CS or A4050CS (bigger) would be good choices. The A4050CS is huge though.

Oct 14, 2013 at 11:43 PM

Cableaddict
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p.1 #3 · Good medium-sized boom arm?

Thanks, Sheldon. That A4039CS combo looks pretty good.

- but I REALLY don't understand all these load ratings. "It's more about the bending twisting force that can be put on a stand by a big long heavy lever." SO the load limit is calculated how? At what point in the system?

How can that A4039CS combo hold so much more weight? It isn't as heavy & doesn't look as beefy as my stands with some of those arms. I've also seen guys put strobes & big modifiers on cheap import stuff, like those $30 air-cushioned stands & booms with plastic grips, and you don't see constant reports of failure. (or do you?)

So frustrating....

Oct 20, 2013 at 02:20 AM

aborr
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p.1 #4 · Good medium-sized boom arm?

A 'baby' (5/8" pin) stand fitting is good for about 35 lb loads. The Matthews Mini-Math and the Avenger D600 are both 'baby' booms and are pretty much equivalent. They're both steel and have tubes and pivots that are capable of carrying about the same weight. If you go to a Hollywood rental
place, you'll usually find Matthews; in New York, they'll more likely carry Avenger.

I use a Mini-Math arm with monolights that weigh maybe 6 lbs with a reflector and
accessories like gel holders and barn doors. If you extend the boom 4 feet horizontally
from the pivot, that's a force of about 4x6 = 24 foot pounds pulling on the stand. If you hang a 10lb sandbag from the other end of the boom, it needs to be about 2 1/2
feet from the pivot point ( 10x2.5=25 lb) to balance the load. The combined weight of
the light, sand bag, and boom is safe for a 'baby' pin. You don't want to get more than
a few pounds off balance, or the whole rig becomes hard to adjust and unsafe.

The Mini-Math (or the Avenger D600) is fine for medium weight lights at moderate distances. If you expect to put a heavy monolight with a big softbox 6 feet from the
pivot, you should probably look for stands and booms designed for heavier
'junior' (1 1/8") fittings.

(The terms 'baby' and 'junior' are old school Hollywood names that refer to the
size of the lights they were designed to support - a 'baby' was a 1000 watt fresnel
spotlight and a 'junior' was a 2000 watt light.)

Oct 20, 2013 at 08:54 PM

Sheldon N
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p.1 #5 · Good medium-sized boom arm?

The big difference between the A4039 and the other stands is that it's a steel stand vs an aluminum stand. The primary vertical stand poles are just beefier than on aluminum stands. The D600 boom is steel, so I wouldn't worry about that, just the underlying stand. I could see an aluminum vertical stand post bending/breaking if it was fully extended with an off axis load on a boom, or with twisting force from the wind.

I have no idea how they calculate the weight ratings, or if the ratings are compatible across different manufacturers. I'm sure they are all conservative, and that it would take a lot more to actually break the stand than the weights they post.

For me, the weight limit is about how much I'm comfortable hoisting with one hand up while I try to tighten the stand with the other. It's also about weight up high vs a stable base. I feel a lot more comfortable with the A4039CS since there's a lot more steel in the base/legs and it doesn't feel as top heavy (as compared to a steel boom balanced on a lighter aluminum base).

There is NO way I'd boom any larger light fixture out in the wind on any of these. I've had a 53" Octa on the 4039CS in a basic vertical stand configuration in moderate wind, and even with 20lb of counterweight on the stand I had to recruit an assistant to hold the stand in place. The light fixture also wanted to spin on top of the baby pin.

However, indoors the 4039CS can boom out a pretty large fixture. Here's the giant 74" EL Octa indirect modifier hung out on the boom.

http://img.photobucket.com/albums/v483/sheldonnalos/_MG_7085.jpg

Oct 21, 2013 at 12:38 PM

Cableaddict
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p.1 #6 · Good medium-sized boom arm?

Great information, guys! Thanks.

Oct 22, 2013 at 05:02 AM


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