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Old November 18th, 2005, 08:06 PM   #1
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Softbox Flammability?

Looking to purchase some largish Softboxes @ 32 x 48 filled with 1000 watts and one of the things I am concerned about is Softbox Flammability.

Looking at the various designs it seems that the metal speedrings are in physical connection with the lamp housing and therefore, like barndoors, could reach a few hundred degrees in temperature; further the dome of the softbox terminates in a sort of roll collar at the speedring.

Thus the material/fabric is in direct contact with the hot speedring, so my question is this fabric likely to become scorched or even ignite?

Surprisingly, I cant seem to find tech data on the flammability aspects of softboxes, can anyone share the knowledge?
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Old November 18th, 2005, 08:45 PM   #2
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As long as it is for a hot light.. and not a strobe

And you don't put some really hot light in some really small lightbank

You should be fine

www.chimeralighting.com might have some date on our stuff since I know we test it in Boulder where it is made.

Some brands may be better constructed than others
last longer than others
while retaining shape and color temp for many many years.

Some might be cheaper, some might cost more.
None of them most of the time will burn up.

some brands might be found in any grip house in the USA and on almost every set.

Just like good clothing a good lightbank will last for a decade or more most of the time with proper care and common sense.
Chimera can refurbish banks if needed out of warrenty which is 5yrs.

I wonder what light you have?

If it 2k or under a Medium Video Pro 36x48 is good.
Almost everybody rates by wattage.. do you really know how hot your light is anyhow?
I know sometimes we use tota's one of the hottest around and Jerry Grey at chimera does a lot of the testing.
There might be some Promos at the dv show
Chimera has a good student discount 25% off retail if you can use that

So I am going to guess you have some open face or Frez
The Chimera back flaps can kind of lay over the light, they might yellow after long long use.
Many people leave that back flap open to help vent.
If you have a fresnel we should talk about it since they won't fill the front face of any normal lightbank even at full flood. It works but vingettes. Actually in the Med bank it won't be too bad.
24 inch depth for video Pro 36x48.
36 inch depth for daylight jr
Just for info
There is a shallow bank video pro but it is really only good with joker bugs, other hmi's with bare tube design due to the lack of depth. for light to spread they work great with Tota's or Baglites.
There is a new 5ft Octaplus bank that is catching on.. it can convert later to a 7ft bank.
The 3ft is the one I like the best for its profile and perfect small location size.
Again depending on how directional your light is
Any how stay well
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Old November 18th, 2005, 08:47 PM   #3
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JOhn,
Yes, flammability is an issue. One thing to look for is a softbox for CONTINUOUS lighting, as opposed to strobe lighting.

Chimera is the gold standard of softboxes (IMO) so take a look at how it SUPPOSED to be done. Steel speedrings - (Plastic ones are fine, for STROBES)
The rod tips are made of steel/alluminum. Plastic rod tips can melt inside the hot speed rings. Vents on the boxes that can be opened to allow air to escape..

Photoflex is also good, but there is a lot of imported stuff on ebay, that is either designed for strobes (and so made with plastic and 'airtight') or simply poorly made.
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Old November 19th, 2005, 10:16 AM   #4
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Thanks for your replies much appreciated

Richard Veil:

I crawled all over Chimera site and couldnt find info on flammability data , nice lighting demos by the way.

In England for insurance purposes electrical gear has to be PAT tested for safety; there are also fire hazard qualifications which have to be met and when they do fabrics are given a Kite symbol to indicate their usage - otherwise its prohibitively high premiums - which mostly means we cant use the gear.

The lights I propose using are Braun open face broads fitted with a ribbed safety glass diffuser, almost cube shaped and have silent fans. They take P type GX6.35 bulbs (superphots) in ratings from 300, 650 and 1000 watts - pretty much ideal for softbox purposes. The metal points of contact with any clamp on speed ring are definitely greater than 100C and the light is rated at 30C when 0.5metre from the bulb (in the beam)

I want to use up to 1000 watts - so it means largish softboxes - so yes the Medium Video Pro 36x48 is a candidate provided I can get info on where the Chimera back flaps are in contact with the speedring; which is the only point of potential fire hazard that I can foresee at this time.
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Old November 20th, 2005, 09:36 AM   #5
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HI John.. send an email

to..

sales@chimeralighting.com

tell them you were talking to me online and I thought they might have the info you are looking for.

thanks

I know we did heat testing so we should have the data.

Thanks

r
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Old November 21st, 2005, 05:05 PM   #6
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Chimera doesn't remember the data I thought we had..

but I got this much

The tables in the catalog have maximum WATTS per Lightbank, but not degrees.
We've done heat testing on some of the Small Video Pro's that indicate that
the temperatures on the top flap of a Bank with a 750w Tota Light do not
exceed 300 degrees. We also know that the heat dissipates through the
Lightbank so there is no significant heat build-up inside the Bank.
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Old November 22nd, 2005, 07:44 AM   #7
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Thanks Richard;

just to confirm my understanding based on your findings - that the temperature on the top flap of a Bank in contact with the speedring is of the order of 300 centigrade and will not smoke or ignite under these conditions?
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