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Studio flash tube explosion... flying glass.
This subject came up in another thread. Since it was a tangental discussion to the OP, I decided to start a different thread. Some studio strobes have flash tubes like this...  Other studio strobes have the flash tube enclosed in a protective glass shield, like this...  Some have argued that the lower image above, has a shield whose purpose is to protect the expensive tube. While the shield may offer that type of protection, I believe the primary purpose of such a shield is to offer protection from flash tube explosion. Others claim that flash tubes don't explode. Since I know a photographer that had one explode injuring a model, I did some research, and found that it seems to be a reality that they do, in fact, explode. I found this... "Catastrophic failure...The resulting explosion creates a loud sonic shock wave, and may throw shattered glass several feet." "Safety... flashtubes should be shielded behind glass or in a reflector cavity. If not, eye and ear protection should be worn." In paragraph #8 under "Safety" it says this? "Flashtubes operate at high pressures and are known to explode, producing violent shockwaves." http://en.wikipedia.org/wiki/Flashtube Additionally, I found that the author of this study, can even predict when it will happen. http://ieeexplore.ieee.org/xpl/freeabs_ … er=4985459 I know it's rare, but just because I lived in a home for 61 years and never had a fire, doesn't mean that house fires don't happen and I should remove my smoke detectors and fire extinguishers. So, my question is... Have you ever had a flash tube explode? if so, please post the general details of what happened. Thanks Jan 21 11 03:56 pm Link i'm counting on my softbox to catch the flying glasses  Jan 21 11 03:58 pm Link one broncolor tube, thats expensive, never with a speedotron blackline, or lumedyne, or speedlite/vivitar/elinchrom or hensel, though dropping a hensel head did break the protective glass dome, the strobe still fires though  Stephen Eastwood http://www.StephenEastwood.com Jan 21 11 04:00 pm Link If you install the tubes with your bare hands, they will eventually explode. The oils from your fingers act like cooking oil and well, you all know what happens when oil get's hot. It will eventually cook the glass and KA-POW! Many people fail to install the tubes using a glove or cloth. Use your bare fingers at your own risk. -Koa- Jan 21 11 07:31 pm Link M Studio Photography wrote: Or umbrella or grid spot. In the case of an AB, the large modeling light bulb will deflect anything that flies. I just can't see a time when I'd be shooting a monolight close to a person without some sort of modifier. Jan 21 11 07:44 pm Link -Koa- wrote: Also, you being the seasoned salt that you are, a reminder about treating packs with respect is probably good advice too. I had an old Norman blow a capacitor on me that brought me back to my days in combat in Vietnam. I thought it was a fast mover getting ready to pickle a load. Jan 21 11 07:53 pm Link Does the glass cover not also provide color correction in addition to safety? Jan 21 11 07:53 pm Link Barry Thoms wrote: Some will have UV coatings, but not all. Other than that, there's no color correction necessary. Jan 21 11 07:54 pm Link I'd be surprised at a flash tube exploding with much force. By contrast, HMI globes DO explode - you won't find an HMI light without blast shielding for the globe (often in the form of metal reinforcing as well as glass). Bear in mind that HMI globes are under high pressure, they operate at hundreds of degrees, and they are continuous light, so they get damn hot. Haven't ever seen this, but the idea of slivers of hot glass flying around is more than a little intimidating... Flash tubes, on the other hand, are only active for a very short time (like 1/1000 second at a time) - they get warm, but hardly hot (the hot part in a strobe is the modelling light, if you use it). If you run a strobe without the modelling light, you'll find it's almost cold. That glass "shield" is more likely to be UV coating (my strobes have UV coating directly on the tubes). The thing that's more likely to explode with a loud crack in a strobe is the capacitors, especially in some of the older models (once the electrolyte has dried up). I've heard a floor pack go once - that's a sound you don't want to hear  I've only had to replace flash tubes once, and that was because the tube simply failed - no noise, no explosion. I replaced the other tube at the same time because it was almost as "burned" looking at the one that failed. Jan 21 11 09:30 pm Link I will never point a flash straight at the model, even behind a softbox or shoot through umbrella without a protective Pyrex cover. I use these:  I use the frosted vertion. It has the added benefit of making the light from the pilot light and the flash to be more correcpondant. Not using this type of protection is irresponsible. Keep in mind that the flying glass wil also be very hot. The pilot light can explode too. Jan 21 11 10:28 pm Link I have had 3 flash tubes and 1 power pack explode on shoots. The last one was at the end of a 16 hour shoot. It was like a gun shot! It was a 10 year old tube in a speedoton black line 102 head in a large lighting bank. I have had just about every equipment failure you can think of. As I see it part of being a professional is how you react and over come things like this. Jan 21 11 10:34 pm Link These have been around for YEARSSSSSSSS! Jan 21 11 10:44 pm Link This is not flash head, but hot light. Fred Greissing wrote: Jan 21 11 10:55 pm Link FYI, for a studio strobe to be UL approved, it is requried to have a shield over the flashtube. There are specifications on how it has to be attached. There are limitations on the kinds of venting that are permitted. So, I will go out on a limb and suggest that the light that supports the top flashtube, the unrotected one, isn't UL approved. The cover is, indeed for safety and protection. Jan 21 11 11:01 pm Link All my lights have dome pyrex covers. For me it's rather protecting the flash tube ( Broncolor tubes=$$$$) but if it reduces the risk of model injury so much the better. Jan 21 11 11:01 pm Link I've been shooting with Speedotron 'Brownline' for well over 20 years... probably well over a million strobecycles... NEVER had a flashtube explode on me...  Jan 21 11 11:05 pm Link photoshutter wrote: The Pyrex dome on the front is the exact dome used on Elinchrom flash heads. Just happened to be the clearest photo of the dome. Jan 22 11 01:04 am Link Select Models wrote: I'm 61 years old and have lived in a house all my life. I've never had a fire in my house, but that doesn't mean that houses can't have fires. For some crazy reason, I have smoke detectors and fire extinguishers. Jan 22 11 01:09 am Link Leggy Mountbatten wrote: I agree. My Photogenic strobes give me two options for flash tubes... "clear" or "UV". The "UV" is yellowish compared to the clear, and is designed to absorb UV light emitted by the flash tube. Also, unlike film, most digital camera sensors are fairly "blind" to UV anyway, so it's not as big of a deal to digital photographers as it is to film photographers. Jan 22 11 01:15 am Link On Broncolor the domes are coloured as you like, the flash tubes are 5900 K, so you can run a clear dome, 5500 K , or 5100 K if I remember right, and you can have clear glass or matte in most of those too for the Pulso, Unilite etc. All for the low price of >200⬠each. The advantage of the coloured domes is you can use clear ones in softboxes that will yellow the light, yet direct silver bowls that would normally be too blue for mixed white product and catalogue fashion. In the old days of film using the correct film ( Kodak EPP was one) and the correct light colour one could avoid white shirts from being odd colours of grey due to the light K temperature AND if there were large amounts of UV causing the optical brighteners in the fabric from shifting the film response. Glad to see things are easier today. Jan 22 11 02:19 am Link ei Total Productions wrote: Sorry, but this is total and utter rubbish. I have used a variety of UL approved strobes, and none of them have had domes over the flash tube. Jan 22 11 02:22 am Link I've used speedotron blackline for 25 years without issue (covered style). A good friend has used dynalights for 30 years (uncovered) without issue. I did have a modeling light blow during a shoot with a Christmas tree in the shot. We thought it was a Christmas tree bulb hitting the floor, no... it was a modeling light and it took out the flash tube at the same time. OUCH! That pop cost almost $150 at the time. As far as I know no one ever touched the bulbs with bare hands so I'll never know why. I can't remember a time when we didn't have a soft box, grid spot, umbrella, or something else over a head pointing toward a human so the risk has to be incredibly low. I'd worry about a backdrop falling over, a light stand falling over, or the model falling off a chair before lights exploding. This is why you have a general liability insurance policy for at least a million... right! Jan 22 11 02:43 am Link I mention this during the before shoot safety briefing that models should always be ready to duck exploding strobes, I also remind them that their posing stool can be used as a floatation device. Seriously, what are the odds of this happening compared to the odds of the model tripping and falling or getting hurt any number of ways during a shoot? Jan 22 11 03:50 am Link Select Models wrote: Statistically you could play Russian Roulette thousands of times and never blow your brains out but........ Jan 22 11 04:46 am Link As a general rule, with unshielded bulbs, is it a good idea to occasionally clean the bulbs from possible contamination? Maybe with something like alchohol wipes? Jan 22 11 07:32 am Link I've had a few tubes explode over the years. Some were my own, some were rentals... Norman unshielded; glass traveled about 5 ft, Bron & Profoto; both were protected with Pyrex domes... The rental Norman (rented years ago in London) head exploded as soon as I test fired .... made a small pop & a nice mess Jan 22 11 07:41 am Link Some strobes do require you to shoot with a protective glass covering the flash tube, others don't need it. Flash tubes as well as speedlites can explode, i have heard a few stories, so your concern is definitely warranted. Strobe flash tubes should not be touched with bare hands, but handled with a clean soft cloth. Can it be that the explosion occurred from improper handling? I have had a strobe fall down and it broke the flash tube and another time the modeling lamp broke from another fall, but never had any explosions... Thank God. Jan 22 11 07:51 am Link I was shadowing a photog and his team about a month ago in a 2 day studio photo shoot. 3 profoto heads caught on fire (not at the same time)... One of them did explode but the tube was covered which prevented injury. Although, the lighting assistant that took them outside each time by the end of the first day and the first two heads had a mild chemical burn on his hands and feeling sick, my thoughts is probably for inhaling some of the fumes as well. I think at the end of the day the studio must have been down about 15k in heads and a power pack. We later were talking about it and figured it was the studios' electric setup causing the issue because it was a true mess just at plain eye sight. Jan 22 11 07:52 am Link On Alien Bees, keep the modelling bulb in the socket. That would deflect any flying pieces of flashtube from going out the front. The ordinary reflector will stop any from going out the sides. However, I can't remember ever having read of any exploding AB flashtubes. As to the modelling light, just use ordinary incandescent light bulbs. They do not have any explosion problem and are as safe as houses. Jan 22 11 08:39 am Link The only time I've seen a flash tube break was on a White Lightning and the tube had been touched a day or so prior. If you don't touch them there's no reason for them to explode. Jan 22 11 04:36 pm Link Aaron D Lewis wrote: Touching a flashtube causes a "hotspot" resulting in the formation of a glass bubble, and eventually glass-melt, and the gas leaks out, usually, (but not always), without an explosion. In any event, I think we all know they should not be touched. Jan 22 11 05:10 pm Link G Ban Photography wrote: Maybe. What some may not realize is, that if they choose to use a non-UL Approved electrical device, their insurance may or may not provide coverage. Jan 22 11 05:15 pm Link Summary Well most seem to agree that flash-tube explosions are rare, of those that chimed in (above), Stephen Eastwood had it happen once, Michael Brown had it happen 3 times, and HD 3 had it happen 3 times. I think it's fair to say, "it happens". There's 7 instances of it above. It's not happened to me, but it did happen to a fellow I know. One of his Alien Bee flash tubes exploded and sent glass into the model's face. Jan 22 11 05:22 pm Link I think the difference is the modeling light. Those that use standard household bulbs generally don't have the domes, whereas those that have 250W or greater halogens do. Jan 22 11 05:40 pm Link Beyond Vanilla wrote: Thanks for the report. Did he have the modelling light bulb in place? Did he have the standard 7 inch reflector or or some other attachments? Jan 22 11 05:46 pm Link Beyond Vanilla wrote: But there are still idiots that don't know this. Jan 22 11 07:57 pm Link ei Total Productions wrote: Frozen Instant Imagery wrote: Are you positive? A lot of people assume UL certification. I just did a search of the UL site for yoru lights and none of them are listed as being UL Certified. Jan 22 11 08:26 pm Link Wow, I didn't think it was that common. I know it's pretty violent when it happens. Jan 22 11 11:31 pm Link Howard Roark wrote: The modeling light isn't what explodes. Modeling lights usually don't have domes. The flash tubes explode and some do and some don't have protective dome covers. Jan 23 11 01:53 am Link Howard Roark wrote: Beyond Vanilla wrote: He didn't say the light explodes. His idea, I think, is that the modelling light is in the way of the flash tube and deflects shards. But also that the modelling light is large enough that any cover would have to be very large and far out and heat resistant. Jan 23 11 05:19 am Link |
