Strobe Lighting

[hairyswaff]

I've just purchased a new high intensity giga-strobe.

 

I've used strobe lights a lot in the past and everytime I hire them I am told a new "legal limit for the usage of strobe lighting"

 

As you can probably imagine I am now very confused about this issue so is anynone able to tell me what they believe is the legal usage limit? Cause I'm doing a show in a few weeks and I'm told the health and safety inspector is ******* and would like to try and avoid an arguement is possible!

Cheers!

[sam.henderson]

AFAIK there is no 'law' as such saying the legal limit for using strobe so it all comes down to your Risk assessments that should include reference (or be based around) recommendations for the amount of strobe usage. I think ABTT have a recommended limit so maybe someone who has got the books could say what that is.

 

HTH,

 

Sam

[eucalor]

For the UK, here is what I've found on enlightenment.co.uk:

 

 

"Guidance exists in 'The Event Safety Guide - A guide to health, safety and welfare at music and similar events', published by the Health and Safety Executive. This is the recently published second edition that is known as the 'Pop Code'. The guidance on this document is not legally binding but paragraph 6 notes that entertainment licensing authorities may refer to this guide when considering appropriate license conditions.

 

Chapter 17 of the guide, dealing with special effects, fireworks and pyrotechnics, includes some advice on strobe lighting as follows:

 

"Carefully consider the use of strobe lights, as under some conditions they may induce epilepsy in flicker-sensitive individuals. Whenever strobe lights are used, arrange for a prior warning to be given at the entrance to the event or in the programme.""

 

 

 

Besides this, UK guidelines suggest no more than 30 second intervals at 8Hz or faster.

[spantax]

I seem to remember from a discusion on the Lightnetwork 4-5 years ago, that England was one of a few countries that actually had laws restraining the use of strobes.

IIRC. BBC had a great influence on this law, and it had to do whit how many images pr. second you where allowed to show on tv before it became hazardous, and could cause epilepsy.

 

I could offcourse be wrong about that law, like I said, it's 4-5 years ago since the discussion on the LN.

However, I would strongly encourage you to take every kind of precaution in regards to strobes. Especially, high powered ones. I was given some advice many years ago, to never use a strobe for more then 5 seconds at the time, keep a minimum of 30 second intervals between each use, and never more then 3 times during 5 minutes. If you are gone use the strobe for disco/club, this would maybe be a "safe" limit to use.

 

I have personally seen a grown person, that has never had any history of epilepsy, get a seisure so strong from exesive strobe use, that he had to be picked up by a ambulance and spent 3 days in the hospital. Keep in mind, that for a person whit epilepsy, it can be enough to stand in front of a lightbulb, and blink his/hers eyes and they can get a seisure.

 

Spantax

LampettGeneralen

[hairyswaff]

Cheers all you've been very helpful

[mac.calder]

I have no idea what you plan to do with your new toy, however I would set stringent guidelines for using it:

 

I would suggest you try and avoid strobes if at all possible, or if not, work out the slowest speed you can use to get the effect, and start as late, and finish as early as humanly possible.

 

Make sure you inform audiences, preferably at the box office, and make sure the box office staff can say "It will occur HERE" - I filled in FOH once (I was sm for the show) when we used a strobe, one of our patrons was epileptic, and he bought with him a blackout mask - like those you get on aeroplanes. He was most grateful we could tell him when the strobing was, down to the line preceding the effect. He came out after the show, and we chatted - apparently he loves theatre yet due to his epilepsy, and the fact a number of places never inform him of strobing or if they do, the lack of when, often resulted in him being afraid to go to the theatre.

 

Then there was another show which almost broke my heart. It was a school production I volunteered for. The director wanted a strobe for a jungle scene - god knows why! A chorus girl mentioned that the strobing made her feel dizzy. I suggested a number of other alternatives which would look much better, both before and after the girl reported it, but what happened? The girl was cut. She was 7 for god sake. She did not have a major role, however her only line was in that act. I feel that strobes are abused far too often. In fact unless there is an effect that absolutely needs strobing to work, I will always attempt to use an alternative first.

[eucalor]

Some figures to clear up misunderstandings:

 

1 in 200 people are epileptic

of these epileptics, only 3-5 % are photosensitive, which means flashing light can cause seizures.

 

So being epileptic does not mean strobes will give you seizures, and spantax' comment about blinking in front of a lightbulb is only valid for photosensitive epileptics.

 

EDIT:

A couple of other points:

 

- 5Hz and slower is considered safe for photosensitive epileptics.

- Most epileptic seizures during concerts, disco etc. are in fact not triggered by the strobing, but by factors like heat and stress.

[spantax]

Some figures to clear up misunderstandings:

 

1 in 200 people are epileptic

of these epileptics, only 3-5 % are photosensitive, which means flashing light can cause seizures.

 

So being epileptic does not mean strobes will give you seizures, and spantax' comment about blinking in front of a lightbulb is only valid for photosensitive epileptics.

 

EDIT:

A couple of other points:

 

- 5Hz and slower is considered safe for photosensitive epileptics.

- Most epileptic seizures during concerts, disco etc. are in fact not triggered by the strobing, but by factors like heat and stress.

<{POST_SNAPBACK}>

 

Thanks for adding this valuable information! I was not aware of this!

 

Spantax

LampettGeneralen

[hairyswaff]

Cheers all, all very helpful!

[si_cole]

I seem to recall the "limit" if you like to trigger a fit is 7hz i.e. 7 flashes a second. As long as it is not on for a long period of time, this should be ok.

 

As people have said, one flash or standing near a light bulb and chases can trigger off a fit. Cover your backside and make it publibly aware (i.e. posters in the venue, disclosure in the program) that you are using strobes.

 

HTH

[Brian]

Cover your backside and make it publibly aware (i.e. posters in the venue, disclosure in the program) that you are using strobes.

Better to let people know BEFORE they've bought a ticket.

[Locksmith]

After a long time of asking, we now display strobe warnings at our nightclub entrance every night, whether 'strobes' are in use or not. We have some moving effects and chases which could possibly be classed as strobes, but I'm not sure, so I prefer the safe option and have the sign up anyway.

 

some of the effects;

 

Martin 812s strobe setting

NJD Datamoon (on sound-to-light, has a flashing mode)

parcans running chase sequences.

 

Am I right in my cautious attitude or should I chill out a bit?

[kalmatthew]

Well IIRC when I read the HSE guidance because we had a girl in year 7 that had photosensitive epilepsy. Even a scan moving past at the right frequency can trigger fits. Although being off center from the effect lowered the risk quite considerably.

[gnomatron]

Am I right in my cautious attitude or should I chill out a bit?

 

You're always going to be better with caution. After all, there's no negative effect from having a couple of signs up at the door, and they cover your ass if someone does have a fit. I only recently got some visible signs up at the place where I work, and we have 5 1k strobes in the main club venue and about 20 movers and scanners with strobe settings. There's no legal guidance, but losing the license will get you fired pretty quickly. There's no need to ever have more than 30 seconds of solid strobe anyway, it's an effect best used sparingly.

[Guest lightnix]

Am I right in my cautious attitude or should I chill out a bit?

 

You're always going to be better with caution. After all, there's no negative effect from having a couple of signs up at the door, and they cover your ass if someone does have a fit...

<{POST_SNAPBACK}>

Agreed. Many people seem to be doing this now. I just booked tickets for Star Wars this weekend and there was a warning on the Odeon site that the film contained "flashing lights".

 

Check out this old post of mine from a thread on safety signs, about which colours to use when making them. Signs warning of danger should feature a yellow triangle. AFAIK there isn't a specific strobe warning symbol, so I'd just put an exclamation mark in the triangle and a written notice below.