sandbag recommendation - how heavy do I need?

I have a Flashpoint Rovelight 600 monolight. I would like to take it to the beach for engagement photos and wedding photos.
The only problem is that it is a little bit top heavy. The battery is in the head unit itself.
I would like to use the light on a manfrotto light stand and a medium size softbox.

I am just wondering what size of sandbag do I need? What is your recommendation? We often shoot engagement sessions ans wedding portrait sessions on the beach. Wind is an issue.

As you'll be on the beach, why not take a couple of 1 gallon plastic bottles to fill with seawater. 1 imperial gallon weighs 10lbs (US gallon weighs a bit less) so you should have sufficient with 2 bottles. Empty to carry and the weight is almost negligible.

oharing wrote in post #17852361
Wind is an issue.

How strong will the gusts be? With a sail (softbox), I'd be inclined to attach 3 ropes & stake it down, longest rope toward the wind, or use an assistant to hang on to it.

Beach engagement photos...rather than water, why not simply three lines that attach up high (near the strobe) and attached at the ground to some simple stakes that are inserted into the sand?

As for weights, do not forget about physics and LEVERAGE...if the wind puts 10 lbsl of lateral force at 60" height, while the tripod feet of the light stand has a 30" diameter, the RADIUS of the tripod feet is 15" so the mechanical advantage is 60:15 or 4:1, so you need 40 lbs at ONE of the feet to offset 10 lbs. of lateral force up high... which is the rationale for anchors putting their force up high rather than on the feet of the lightstand!

I got the point. I need something really heavy in REAL wind. It is hard to tell how heavy weight I need because it really depends on the environmental conditions...
I like the water idea! the only problem is that I need to attach the bottles to the lightstand somehow....? Any suggestions?

Not living near a beach, this is theoretical but I do wonder just how much anchorage you'd get with stakes into the sand? It may well work, perhaps it wouldn't - that's something to test in your location(s). Certainly lines/stakes offer distinct stability advantages where the staking points are reliable while bottles of water would have advantages on a more frangible surface perhaps. It's amazing how great the similarities between outdoor lighting rigs and windsurfing.

As far as fastening water bottles to light stands, I braided some 550 paracord with loops and attached dog lead clips. I can wrap the braid round the centre column, one leg, clip to the end of a boom arm or what ever takes my fancy. I also use these in the studio with ordinary sandbags.
If you get a couple of these water carriers, you can get 44lbs of weight per container without carrying more than a few ounces to the location ( apart from one trip coming up from the water's edge, of course ). I already had some from the 'good old days' when I could not only get down into a tent but also get back up again afterwards. Tatty, disreputable, maybe 30 years old but they still work, even in my local park or other grassy areas; anywhere there's a water supply.

No single solution is a catch-all, of course, but if you're working alone (no assistant to 'just carry this weight/hold this lightstand') the water bottle provides a viable and versatile answer to the question you actually asked.

I made a graphic to illustrate forces involved (dependent on wind speed and shape and size of light modifier), and why a guy line is better than weight directly applied at the leg. Also, the forces applied against the ground stake (in green), the force vectors are, of course. dependent upon the angle of the connecting guy line.

As for stake resistance in sand, by simply driving the stake into the ground perpendicular to the guy line its resistance is increased, and by using an L- bracket metal shape rather than a solid (and somewhat cylindrical) stake increases its resistance, also.

Outstanding graphic, Wilt! A picture is worth a few hundred words here.

oharing wrote in post #17852361
...I would like to use the light on a manfrotto light stand and a medium size softbox...Wind is an issue.

There is a whole range of lightstands from Manfrotto and others, and a large range of wind as well. Duh.

Quick story, quite a few decades ago, in the era of multi-image slide shows, we set up 3 10x14' "fast-fold" screens in an amphitheater. These have a framework and legs of 1-3/4" square steel tube (plus or minus, it's been a while). Lots of sandbags! We were just standing back and admiring our work when a little 3 mph breath of wind came along and snapped two of them off. Oops. They were rentals...

You're probably taking my point; sandbagging may keep the base of a stand in place, but depending on the size of the "sail" and the speed of the wind, it isn't that hard to break the lightweight stands most of us have for indoor use.

After all, they're designed for vertical loads, not sideways loads! OTOH, I have one all-steel stand that must weigh 30 lbs. It could stand up to a 30mph gust no problem, if bagged...

A long way of saying that what Wilt & others have suggested: Line(s) and stake(s) will almost completely take the strain of the sideways load off the stand.

***************
The end of the amphitheater story: Fortunately we were setting up the day before the show. At 8am the next morning we had a stage lighting crew build 50' of truss 12' in the air, bagged, lined, and staked. We tied off the screens to it, and the show went on! I was able to get the screen legs repaired at a machine shop, better than new...

Dear OHARING/Otto,

Notwithstanding WILT's excellent points & diagram of grade 8 physics leverage principles...

SUGGESTION ONE-
Perhaps, you could creatively use some of your existing on-location equipment weight, (rather than inconvenient, heavy sand bags).

Just one approach, but here is what I utilize for occasional destination-weddings (I always try to operate with minimal amount of gear).
Motto: Less is often more!

For fast, dynamic on-location portraits & any time-constrained weddings, I try to avoid sandbags, but never compromising safety, clients, public, or lights.
[But if I do use them, I have one or two these very compact Matthews BOA 15lb bags, which are manoeuvrable & 1/3rd the size of traditional saddle sandbags.
http://www.bhphotovide​o.com …enior_Boa_Weigh​t_Bag.html
If I use a Lastolite 6ft x 6ft scrim or large California Sunbounce then use 35lb bags.
http://www.bhphotovide​o.com …35B_Saddle_Sand​_Bag.html].

Instead, I usually prefer to use my existing light bag & lightstand bag for ballast, placed/hung (with a nice discrete refined black twine, with clip)
https://www.homedepot.​ca …rity-snap.1000401131.html
with top of the small twine approximately 3 feet up onto one of the lightstands adjustment knobs, on each of the two Manfrotto #1004BAC lightstands and the bag then draping down the remainder of the light stand.
http://www.bhphotovide​o.com …C_Alu_Master_3_​Riser.html

If windy, then on the windward side which will likely be receiving any lateral force/wind;
or if no wind, then on the opposite side of either of my Profoto B1's, for counterbalancing & ballast.

i.e. One existing equipment bag as ballast, for each 12 ft Manfrotto #1004BAC light stand. This setup works well, is effective, efficient & enabling fast set-up/tear downs!!

For example:
- a Profoto Double Bag:
http://www.bhphotovide​o.com …o_330211_Double​_Case.html
[which also holds spare Profoto B1 batteries, B1 battery-charger, barn doors, grids; when hanging as ballast obviously excluding 1 or 2 Profoto B1's]
and
- a Manfrotto lightstand #LBAG110 Bag:
http://www.bhphotovide​o.com …BAG110_4_Quick_​Stack.html
[which also holds, 1- 7ft Matthews Reverse, grip hardware: such as 2- Manfrotto Justin clamps, 2 Manfrotto #026 umbrella adapters, Surui #P-326 monopod for a strobe or speedlight light-stick, Profoto Deep Silver- Medium umbrella with front cover, Profoto 2ft Octa softbox (with rods & diffusers in place to minimize set-up/tear-down time); which when hanging as ballast obviously excluding the 2- 12ft Manfrotto #1004BAC lightstands].

While not in the intense Florida sunshine you have to contend with, I from May to September for outside on-location applications, after positioning subjects & camera positions utilizing existing ambient lighting, often prefer bare Profoto B1 strobe, (with its built-in frosted glass front, or with OCFbarn doors, or feathering) to balance the sunlight, or to create highlights, to direct a viewers attention, rather than wind-catching power-eroding light modifiers.

SUGGESTION TWO-
If you have an assistant, just use a light stick, rather than a light stand.
for example see this Jason Lanier video: https://www.youtube.co​m/watch?v=4zf_XPZnvXk (29:29 minute video)
I have my assistant use the Surui P-326 monopod, which I find works well. It's subtle, fast & helps accuracy.
http://www.bhphotovide​o.com …Section_Carbon_​Fiber.html

I'm a petite 5ft 2.5 inch female.


ALSO (important point),
Sometimes the less conspicuous more discrete you are, the better.
e.g. no light stands and particularly no light stand support wires/lines. (no photography lighting permitted, or light-stick only city by-laws)
In an increasingly populated world, you know better than I, that most cities (& even towns), tend to hinder rather than help professional photography activities with their ever restricting policies, or required permits with increasing city-fees.

Just one view & thoughts.
Good luck & continued success.


Regards,
Mary

P.S.
Otto, I enjoy your (& your wife's) photography work, observing it over the internet. You have progressed magnificently since approx 2009, when you were intensely studying others work & considering (the switch from Canon to Nikon); you have been a very discerning learner, with an inquisitive mind - well done!

Thinking of inquisitive mind, may I ask which camera you are using now for still photography?
(reviewing your portfolio, I might guess you made the change to Nikon in approx 2012?)
I know it's about the photographer, not the equipment, but the aid of technology, in skilled hands, I think does help in differentiating oneself in the upper-end of a target market.

Pardon me for pointing this out, but on the "About Us" page of your lovely web site, there appears to be a spelling error.
reads: "yatch" (unless this is a casual new unofficial/alternative way of spelling the word in our hi-tech world)
should read: "yacht" (the established way of spelling the word)
since, incorrect spelling may potentially reduce your credibility, with some in the market you are targeting.