Newbie Power Question - Overloading a Circuit = damaged bulb or fixture?

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yophoto91

Active member
Hi all,

My experience working with high-powered lights is limited. In the past I've worked in studio environments where power overloads were never an issue. Recently, however, I've been putting together a personal fresnel kit for shooting in homes, small businesses, and an occasional larger warehouse-type environment. Anyway I just pulled the trigger on two used Mole 407 1K Babys and two Mole 5291 2k Juniors. My question is if I do manage to overload a circuit in a typical home-like environment with say a 15/20 AMP box will the lights simply shut down safely, or is there a possible risk of the bulbs blowing up, or even worse, the fixtures? Anytime I've blown a circuit it has been with lower wattage lights like 650s. I'm just wondering if these larger 1k and 2ks are more prone to physical damage given that they are considerably hotter lights.

Thanks for your time and help,

Mark
 
Blowing a breaker or fuse is no different than turning the switch off.

More information - If you do blow a breaker, it means that for some time, the bulb was pulling more power than allowed. Contrary to popular belief, breakers do not instantly trip when you go over the rated amperage. So if you are running over the rating, you may be running at a lower voltage than the normal 120/230VAC. This will not harm the bulb.

The most stressful part of a bulbs life is the on/off temperature cycle.
 
Most businesses in the US have 20 amp circuits, unless it's some very old building. Many homes have 15 amp circuits. It's not exact, but assuming 100 watts=1 amp will give you a safe guideline for a circuit - but you don't often know what else is on the circuit; and there's amperage loss to wire resistance, and breakers can get weaker as they age - so often the full 20 amps isn't there.

One thing you can do is use a power strip with a breaker - they're almost always 15 amp breakers, and that can save you from hunting down the fuse box.

But overall, taking 2ks out to location gigs can be a little nuts in this day and age, unless you just really love tungsten or everywhere you shoot is lit by tungsten and has no windows. Gelling those 2ks to daylight gives you about a 650 watt equivalent light, but you're still pulling all those amps and generating all that heat. Add in the fact that fresnels are really inefficient lights.

If your budget is tight, I'd seriously look into something like a couple dual and a quad biax flo - chinese Kino knockoffs. They're just dirt cheap and give you lots of soft daylight. You can use your fresnels for rim lights, picking out details, etc.

If you're still going to go full tungsten, look for some open faced lights with barn doors that use the "work-light" style stick-globes (rectangular theatrical lights are great). The globes are cheap, available from 100 to 1K, and easy to swap. You can use your fresnels for bounce and diffusion, but you're better off using open-faced lights for that, and you'll likely use bounced or diffused soft lighting much more than harder fresnel lights. I've done hundreds of corporate overviews, interviews, music videos, commercials, and never used more than a 750 fresnel on anything - but I've used piles of Kinos and lots of open-faced in the 300-1k range.
 
part of me wishes you had consulted the forum prior to making your purchase. Not that you have to, of course.

The reason why I say this is because for shooting in residential locations of commercial locations where you have limited power supply, it could be helpful to invest in LED fixtures. You can get a significant amount of output, with decent CRI, and the ability to change temperatures without gelling. The good ones can be a bit pricey, but for the price you paid for those moles, you could have gotten yourself a few fixtures with decent output, nice color, and adjustable temps.

They are worth the investment because you can run a cool set, not waste time with fuses and strike times, and save time and output not needing to gel.

Sorry to to go on at length about should have, or could haves. Plus, I don't mean to assume you don't know what you are doing, because I'm sure you do and your investment will still be able to give you great results. Just thought I'd throw it out there, in case it can add to the conversation.

Ah, the tip of using power strips to minimize breaker box runs is spot on!
 
Excellent, thank you Paul. Good to know.

Thank you, too Michael. Good info. Other than the cost-benefit of open-faced lights are there any other advantages of using open-face lights as bounces or with diffusion? It just seems like even with barn doors it would be a bit more difficult to tame the spill of an open-face compared to a fresnel. I do prefer the look of tungsten, but it looks like I may have understimated the practicality--or even possibility--of shooting with 2ks in a home or business environment. The kino knock-offs sound like a good idea for sure. Over on the BMCuser forum there is a thread with some people using the Impact brand fixtures and fitting them with Kino bulbs. Apparently they look the same. Is this similar to what you're talking about?: http://www.bhphotovideo.com/c/product/937705-STUD/impact_frc_24_ready_cool_4_lamp.html/mode/edu

I appreciate it Rafael. Yeah that makes sense. I do personal narrative work every so often and for situations like that where time and heat are less crucial I would love to utilize the bigger frensels for their tungsten look. It seems, however, I was a bit naive in thinking that I could double-dip the usage of the lights and use them predominately for commercial work too. I have had my eye on the Aputure LightStorm LED which seems to be getting decent reviews...just waiting till NAB before I make the purchase in case they announce a new model. It seems like a couple of lower wattage fresnels/open-faces, a few knock-off kinos, and maybe a 1x1 type LED may be the best bet for home/business type commercial shoots.
 
yophoto91 said:
Excellent, thank you Paul. Good to know.

Thank you, too Michael. Good info. Other than the cost-benefit of open-faced lights are there any other advantages of using open-face lights as bounces or with diffusion? It just seems like even with barn doors it would be a bit more difficult to tame the spill of an open-face compared to a fresnel. I do prefer the look of tungsten, but it looks like I may have understimated the practicality--or even possibility--of shooting with 2ks in a home or business environment. The kino knock-offs sound like a good idea for sure. Over on the BMCuser forum there is a thread with some people using the Impact brand fixtures and fitting them with Kino bulbs. Apparently they look the same. Is this similar to what you're talking about?: http://www.bhphotovideo.com/c/product/937705-STUD/impact_frc_24_ready_cool_4_lamp.html/mode/edu

I appreciate it Rafael. Yeah that makes sense. I do personal narrative work every so often and for situations like that where time and heat are less crucial I would love to utilize the bigger frensels for their tungsten look. It seems, however, I was a bit naive in thinking that I could double-dip the usage of the lights and use them predominately for commercial work too. I have had my eye on the Aputure LightStorm LED which seems to be getting decent reviews...just waiting till NAB before I make the purchase in case they announce a new model. It seems like a couple of lower wattage fresnels/open-faces, a few knock-off kinos, and maybe a 1x1 type LED may be the best bet for home/business type commercial shoots.
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With fresnels, it's very difficult to fill an entire panel - say a 4x4 - with light vs. having a little spot on it. (And I love fresnels, I own about nine from 2" to 8" lenses - those tiny antique 2" fresnels are wicked). Since most panels are rectangular, the rectangular lights are the easiest way to fill the panel. As far as spill - or really, bounce from a diffusion panel - you'll get that with either fixture. if you're doing a very low-key look, you really need at least a medium softbox and a grid to keep the rest of the set dark.

Yes, the impact fixture is the type I refer to. And chances are, you don't need to add a hundred bucks in trumatch bulbs - just shoot a raw still of a face and a gray card and open it in camera raw, and play with the sliders and eye droppers until the RGB values of the gray card are very close (like 125r,125g,125b) and the skin looks good. Look at the temp and tint sliders and you'll have a good guess as to any CTO, CTB, +green or -green needed - if any. Gel up and shoot another still until it's dialed in - or just WB to the fixture. If you WB to your key, your hair lights and BG can go fairly far astray before you really see it. Or test each fixture you own and mark on 'em the gel combo to get clean daylight.

The 4 bank biax is a freaking workhorse - just clip diffusion across the barn doors or hang a sheet of ripstop and you have a decent softlight that's about 1k. find a unit with all 4 barndoors and you have a softbox in a minute when you clip the diffusion on.

I differ from Rafael and others about the LEDs - unless you have money to brun, they're lousy keys unless you're in a very dark space and don't mind shooting at higher ISOs. I have the Aputure ($270 and a pretty great little light) but it sure ain't no key - it's dynamite for hair/cheekbones, picking out a detail in the BG, etc. It's tiny, has a remote dimmer, etc. I keep a ziploc of trimmed gels to tweak the color - the bi-color LEDs? Go full daylight and you're only using half the LEDs - mehh, for me anyway.

Keep in mind that none of these solutions - not your 2ks, not my biax, not the LEDs - will light a face in an office with a full-on corner-window as the background (unless you like the window to be blank white). If you want to hold the sky or detail, a 575 HMI par can often work as your key, but even that can be tough.

Not trying to sound pedantic and there are plenty of ways to skin a cat - this is what's worked for me, YMMV!

One of my open faced lights - I think there are some on eBay now for 20 bucks or so. good workhorse lights when you need tungsten and you can get 5 or 6 in a long dairy crate or footlocker sized case:

DSC_0018.jpg
 
To complete your kit you will need 2x 300w and 2x 650w. Sometimes you will pick 1k to light, barely ever will you use 2k. I still use tons of tungsten units on small shoots - they simply work.
 
You just can't beat tungsten when it comes to how it renders skin-tones(except for REAL sunlight). I just added two more tungsten fixtures, Arri 750 open faces(Arri says equivalent to 1K when lamped @575), to shoot through bigger Chimera's or bounce. I shoot tungsten whenever I can. I have HMI's, I love my Astra's and I still carry around my Kino's, but to me tungsten is king.
 
David W. Richardson said:
Please show me where you find these on Ebay. I've had no luck, but would love to pick up a few for an upcoming shoot. Thanks!
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Oh, man - you have to go hunting. Right now, in ebay/photo/lighting/continuous lighting, if you select "used" there's 1600+ items. And with tons of those lights coming from estate sales and so on, people don't know what to even list them as.

You can try searches for "open" (for open faced), "reactangular", "colortran" (since there's often those), "cyc", "Cyclorama", "nook" for nook light… last time I searched "fresnels" was where I found several… an example of what I mean!

if you search Colortran today, you'll find a lot of them, some missing barn doors, some overpriced, some look good. Take a look at this one.
 
When you enter the location find someone who knows where all the breakers are, Just incase they do trip. Also if you do decide to use your 2k's, try to use separate 15/20 amp circuits. You want to have the full capacity of that breaker without sharing it with any other appliance etc.
You can also have a look at the Mole fay lights. They come in single, doubles and 4light fixtures etc. You can also change the bulbs from from daylight to tungstern in the Fay light fixtures.
 
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