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LSO-- Laser Safety Officer- a tutorial--


Well-known member
Apr 2, 2009
welcome and TY for reading--


This tutorial will go over the basic outline of the LSO short course.
These are offered at most SELEM events, At FLEM sometimes (because its near to ILDA) and at most big ILDA meetings-

The 'regular' course spans three partial days but even it does not cover in detail everything a LSO needs to know (or to pass the exam) 'normally' IIRC the long
3 day course costs more too- At SELEM ILDA kindly lets us do the one-day short course for lower cost.

TBH I am making this thread not only for those at LPF who want to know more about safety with laser projectors and lasers in general BUT for me as I failed the exam at SELEM 2013 .
(btw to take it at SELEM you will need to spend another night as it happens the day after SELEM ends at the Holiday Inn Express where most stay during SELEM)

update - turns out that another in my class and I (at least) did not have complete training manuals missing 20 some pages which we were allowed to us during the exam- I have been offered a free home 'do-over' for the exam.

AFAIK there are not very many LSOs in the USA- being one can make the difference when it comes to finding a job involving laser projectors/shows.

In the event that a show company gets sued having a trained staff member who is responsible for safe use and training others can make a HUGE difference..

I have about 175 days before SELEM 2014-- If I can afford to go, I can re-take the exam(0nly) for free (I think)- my other choice involves another $100 that I do NOT have ( a take-home email exam with the same two hours to complete & send back)

Another benefit from the LSO and other laser safety courses is knowing how to become a varianced operator which is a must-do for any public display of lasers would technically be 'illegal'.=

.. But IMHO being safe is the most important--so even if you have no intention of ever becoming a LSO, I hope to place here as much info as possible to help you to be safe-- being safe and 'legal' is the best- but at least being safe is good reason to join us in this thread..

What we discuss here will only HELP you to pass the LSO exam AFTER you take the course , (should you ever take the course)--but in no way will it cover every possible exam question--as that does not happen even with the 3 day course. And the learning never stops. goes on forever.

The Exam
you get two short hours and only enough 'spare' time to look up a few answers- we get to use everything we want short of asking for help from others taking the exam-- I saw some very sad faces at LSO SELEM 2011- IIRC only about half passed- my class had MUCH wiser students including one who was retaking both the class and exam and one guy who could write a book on laser safety Steve Roberts- I will urge him to spare us a few minutes from time to time and give this thread some help-

Be sure to thank Steve for helping us out--- he does not get that often enough-

There are more than 200 powerpoint slides-shown at the class.

Some buy a textbook-( I paid 100$ for mine) some get by w/o- its NOT a cheap book -- found mine at Amazon but was told I paid too much for my used edition...
has excellent diagrams on the anatomy of the eye=- by far the most in danger is our eyes.

.most of the book covers other types of lasers & we do not need that-- maybe you can find it at a library and copy the best pages-
'Safety with Lasers and Other Optical Sources'

David Sliney and Myron Wolbarsht

Many links can be found on-line- at ILDA, ILD -Pangolin and Pl-Ex-Coherant, UPenn ..etc

for the exam you need the on-line MPE calculators- unless math is your strong point- (not mine)

WE were given a 60+ page Training Manual- we are NOT allowed to copy w/o permission it but I will be using it as a guide to this tut.

This is for US Laser Light Shows and Displays Aug 2010 Version 0.92.

being very dangerous in some cases proper training is a MUST!

The LSO courses (even the 3 day one) do NOT cover everything
and there are questions on the exam that were not covered in class.

Part 1 covers the fundamentals of Laser Operation-- its 30 pages long.
Part 2- Info for LSO and others who are responsible for safety.
Part 3 Technical Considerations
Part 4 Arizona rules ( one of the more strict states)

If you only 'THINK'you may want to become a LSO I suggest you follow this thread and start a word file to copy all the links-

to fully understand safety you first need to know how lasers work- the fundamentals. A full understanding of the effects lasers have on our eyes and skin is next --
the different kinds of hazards including non-beam (like a laser falling or trip hazards. ) You need to know the laser classifications and the control measures.

I invite any who see mistakes from me to let me know.

Part 1 will begin on post #3
I will be adding more as time permits-
there is a LOT to cover- and this thread will take months to be anywhere near complete--


I may create a two hour exam when this tut is 'done' and we can see how you did with just two hours--

FYI there will NOT be a LSO course at SELEM 2014 UNLESS enough sign up for it- the planning is well underway and some are already wanting to pay 'buffo' for their spot at SELEM-- which will be one day longer(shows start Thur) due to popular demand..

Aug 14 to 17--2014 set up starts on the Wed. the 13th IIRC

need info?- SEARCH 'SELEM Laser'and see many cool vids at YTube.

:san: hk


there were enough to take the class and now they are starting a list for LSO at SELEM 2015 (Aug 12 in Newton NC) on Monday aug 17 8am at HIE.
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New member
Mar 27, 2013
Subscribing. I doubt I'll ever look for work in a laser related field, but I think this is a good certification to have even for a backyard projectionist.

I doubt I'll make it to SELEM this year (family obligations), but I will consider taking this course in the future.


Well-known member
Apr 2, 2009
The most BASIC=== Light Amplification by the Stimulated Emission of Radiation


Basically all lasers produce light the same way. Light from a light bulb goes everywhere- but a laser makes its light (photons) with light that travels in phase to become COHERENT and powerful.

most are MONOCHROMIC (single color)
while other like Argon /kryoton make multiple colors.

The 'spread' or DIVERGENCE is very small unlike a light bulb(non -coherent)

Solid State(SS) lasers used for shows are one of 3 catgories -Arc lamp-Flash Lamp pumped and Diodes.... gas lasers are no longer used very much.

,,Arc lamp & Flash are typically high power YAG. they produce IR(1064nm) doubled to make green 532nm-

being pretty much invisible IR is very dangerous. More so should the doubling become disabled.

DPSS are similar to the larger lamp pumped but are compact.

Laser diodes: the most simple- red being the most common in shows.
Blue diodes are now replacing the DPSS 473 lasers.

Gas lasers are gas filled-with FS mirrors- at each end- one being fully reflective and the light passes thru the other FSM since radiation CAN come form both ends extra care needs to be taken at both ends.

Biological efx to eyes and skin

High power class IIIb and class 4 can cause severe burns.. even permanent eye damage.(the most common injury)

our own eye's natural lenses focus the laser ...as the intensity can be increased thousands of times by the time it reaches the retina focused by our own eyes.

Thus so-called 'low powered' lasers need to be treated with respect. AND Pulsed lasers with high pulse repetiton rates can even cause acoustic shock wave damage.

another adverse effect is called 'Blue light hazard'
some B and G wavelenghts can cause damaging changes to tissue due to a type of photochemical reaction within the skin itself.

Reflection hazards

Specular reflection: off mirrors and glass etc - IF the beam remains 'tight' its no different than a dirct shot-and every bit as the direct laser beam.

Diffused reflections are when the energy is scattered and not as dangerous. but at high powers just looking at the dot on a white surface can be bad.

Safe set up reqiures careful aiming at all times- avoiding anything reflective.
Always terminate beams on diffuse surfaces, and when possible , terminate high powered beams in areas the audience can not readily see.
its best to do set- up with NO non essential persons present. (not always very easy)

NON BEAM hazards.
not to be ignored- the beam is not the only hazard-
There is also..

electricity---dangers especially those using higher power source or water cooling.

another hazard is slipping (on the water) aside from shocking. (electrocution)

Ionizing radiation hazards--

This is concerning non visible radiation like UV(not used much anymore)

LASER Classifications

Class 1" low risk less than .39mW
Class 1Mwavelengths between 3902.5nm and 400nm- safe unless you are looking thru binocs etc.
Class 2-- (old class II)can produce levels of radiation that could cause eye damage.
but not likely -- less than 1mW.
Class 2M 400 to 700nm potentially dangerous when viewed with an optical instrument.
Class 3R-(ols class IIIa)safe when diffused reflection but NOT direct exposure- emits less than 5mW.
Class 3b (old class IIIb) hazard direct normally safe when viewing diffuse reflections.
less than 500mW- skin and eye hazard.
Class 4 (ols class IV)
hazardous under both intrabeam and diffuse reflectiob viewing conditions. More than .5W (continous) almost ALL laser shows are class 4 lasers.

CONTROL measures to insure safety
1) Engineering (tech controls)-most effective type
include housings -interlocks-emmission delay and warning lights. IF EVER overridden injury can result-
2) Administrative & procedural controls.
training and warning-- OP manuals- visitor restrictions- (non essentials) and education like LSO courses.
3) Personal gear- eyeware- clothing to protect skin as well as eyes.


Well-known member
Apr 2, 2009
Now i will break down the different control measures for each 'type'
1) Engineering includes:

a) protective housing - an enclosure is a must- it limits or prevents unnecessary acess to the beam path prior to the beam aperture. Thus PJs may use turrets- small openings or a window- on the front panel. an opening must be no larger than needed.
b) Interlocks- (0n the housing) prevents access to lasers. These MAY be defeatable but must be reset and w/o the interlock defeat mechamism beibng set, terminating laser radiation.
c) KEY SWITCH= all class4- MUST include a key switch ONLY removeable in the OFF position-a secondary switch close to the operator is need if the projector is not wiythin reach of the operator (E-Stop)
d) Limit open beam path-- no laser leaks in your enclosure-SEAL gaps to block unintentional emissions.
d) Remote interlock connector-
all cl;ass 4 must have one- a mater shut-off or 'panic button' a way be be present to block the laser - (not necessary to stop lasing) so a shutter is often used.
e) beam stop or attenuator-- all class 4 must have permanently attached shutter or attenuator. Thus if power were lost the beam would be blocked. needs to be located closest to last laser combining-
f) Activation warning system or Emission Indicator- must be either visible or audible signal - often a LED or small lamp located on the front panel.
g) Emission delay-- a delay between the activation of the laser and the actual emission of radiation- also known as a 'delayed start' often about 3 seconds.
h) labeling Requirements
Labels= all laser products have these- and they are strict requirements- must match the laser class- kinds of labes:
Certification label- this MUST be in compliance with 21CFR 1040 w/ maker's D CDRH variance number and issue date .

ID label-- identifies the maker's- full name- address and actual place the laser product aas manufactured at, if different from the company address
Warning Logotype label
each class 3b wilk have this..
Emission Apereture labels - Every product must have- these placed close to the apertyure--'AVOID DIRECT EXPOSURE TO BEAM emitted from this aperture'
Non-Interlocked protective housing label- one on EACH anel of the enclosure that may be removed during operation maintenance or service.
AREA POSTING - Appropriate type these are larger signs to keep unathurized persons out of danger areas..

these to must be for the correct classes.

2) Administrative & procedural controls

1) all conditions of the variance must be observed.
2) maintain written SOPs
3)Beams cannot enter audience=NO BEAMS of ANY power -not even class2- unless being pre -approved in the variance.
4) both a vertical (10 feet) and horizontal 8.25 feet separation from audience
5) Always monitor show-- all shall be under direct and personal control by trained and competent operator(s) cvan be an employee of the variance holder and must be trained by someone like a LSO.
6) mount securely-- in order to prevent unintentional movements.
7) Mask beams to prevent exposure- keeps beams from going into unwanted areas.
8) Notify all authorities in advance(in writing!) - such as-federal- state and local authorities providing dates and intinerary with dates and locations--includes fire inspectors as well as local laser health authority.
9) Do not change effects- any variation reqiures reports or suppplements as applicacable .



required for all class 3B or class 4 -must be approved by the LSO - must be written and maintained -- also the laser manual is not an acceptabl subvsitution but may be a part of the SOP.
1) must be used as defined by makers manual
2) all paper work filed and approved
3) follow all alignment and testing procedures
4) follow all conditons pf the variance
50 follow all tasks, rstrictions , and reqiurements as defined bt he LSO.

OUTPUT emission limitations

a standard condition of a varianced laser light show in the US is that the max laser PJ output shall not exceed the level required to obtain the intended effects. so do not use excessive laser power!!

Education and training
all working with lasers must be properly trained to recognize the hazards.
this includes both workshop and actual show environments --

Authorized personnel
Only those trained and well aware of the hazards should be admitted into areas where service etc is taking place

Standard alignment Procedures

Prior to powering up the laser
1) it is the discretion of the laser operator to allow or deny entry-
2)Keep room lights on brightly if possible- this keps the pup[ils small and thus less chance of excessive laser light entering the eye
30 Excules unecessary persoanel
4)use low power lasers for path simulation whenever possible.
5) wear appropriate eyeware and skin protection.
6) Remove personal jewelery-- less chance of reflections
7) Locate all tools and materials before beginning alignment
8)Keep optical table (if any) clear of objectis
9)close the shutter if entering the beam path
10) except when actually needed close the laser shutter
11) use laser-rated beam block to terminate barriers
12) place beam blocks behind optics
13) Locate and block all stary reflections
14) Be sure ALL beams and reflections are properly terminated
15) Post warning signs
16) verify that all paperwork is present and accounted for.
17) Double -check all cables, hoses and other support systems to insure proper function.
18) double check all mounts and safety cables.
19) verify that ALL control systems are functioning properly.
20) Check for any bright-light sensitive devices or materials . This includes: Video cameras, and potentially flamable or heat-damages materials.
21)Check that there are NO unnecessary gaps between the laser source and the laser projector..

beam tables are different and they require different safety controls_
Bounce mirrors must be mounted to be sure they are clear of humans or reflective hazards
for systems using beam acturators and shutters... Verify that all beams and shutters are operational.

SPECIAL considerations for systems being used outdoors--
Of course never lilluminate aircraft- keep all beams from entering the sky where aircraft may be.

ALSO in the US you must have a letter of 'no objection from the FAA.

UPDATE FAA has 'relaxed' some of their requirements and as long as all beams are NOT untermanated--no problems.
you must before a show report to the local aircraft tower as per your pre-aproval from FAA or other safety authority.
Ensure that designated aircraft observers (spotters) are familiar with the particulars of the set-up and discuss any problem areas as needed.
Do not put the laser beam into the sky during set-up when no beams will be going into the sky(terminated)
Spotters only function is to watch the beam postiton to ensure no aircraft or other hazards are near the beam. use od headsets or ebing within voice range are needed.

Special considerations++ for systems being used for audience scanning
Currently these are very rare in the US- this requires a vat=riance for audience scanning--
basically you need:
EXPENSIVE LPM equipment and know how to use it.
Readings must be taken and recorded.
all math needs to be double checked
ILDA recommends taping all shows in case of incident.
Enough cameras should be used to 'follow all the action'
keeping these cameras maintained is often another duty of the LSO.
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New member
May 9, 2013
good stuff, hak! thanks, man...

I don't think I'll ever have a need to go through a cert like that, but I like to learn about this sort of thing.

Maybe we can have a laser safety discussion over some ice cold beer at the TEXLEM event? :)




Well-known member
Apr 2, 2009
You are very welcome Clayton--
I do like an occasional cold beer but pretty much have given up beer on any regular basis--

I have been trying to get a few members local to Houston to met up and do some planning- Maybe you can locate an empty warehouse near Spring that's affordable.
The one I found in 2011 was FS or full time rent I convinced the realtor to rent it for a 5 day weekend- Sitting empty is zero income- Venues(regular) are often too
expensive for us. The affordable places will not be ones that are advertized for rent for short time use. I look for ones with no homes very close- They do not havee to look fancy- as we do not care about that- if it has power (any owner or realtor knows how to get the power turned on for a week ) and a bathroom we can work with that-
The one i found needed lots of cleaning up- that took three of us one day alone.
I found that if you offer a good size deposit to insure the place will be left clean they are more likely to do a short term rental. In some ways LEMs are like raves that only a few people show up for- none have ever been 'open to the public' as no member wants to get sued- That is way its LEM SOP to have ALL who enter the building sign an insurance waiver.

This thread will show you why LEMs are private- Considering the vast amount of gear needing to be 'properly' set up at SELEM we would need a week to set it all up ourselves with following everything needed to be safe and NOT face a lawsuit- Many of the PJs at LEMs are not 'up to code' or are works in progress- Cords are strung every where and we have no signage ( a requirement)-- We do mirror ball laser 'rainbow rain'- an awesome thing to see that is mostly NO longer used in public- as by its nature its dangerous. (audience scanning)

Aside from the obvious benefits attending LEMs is what makes them happen.
It keeps people coming back and bringing guests. Even if all you can do is come for a single day it will make you want to do the entire LEM next time. if you cannot come early enough to help load in and set up or must leave before the take down and load out-- you have missed part of the LEM experience as well as not have helped your 'fair share' Some pros that do LEMs are not only doing a lot of work for others and have MANY thousands invested in gear, they often are giving up a paying gig during the event.
so keeping this in mind is important- whatever your reasons for coming late and leaving early these pros are sacrificing much more than you would be, if you did the entire LEM. They are spending lots of money and time coming and losing money from 'possible' gigs not getting done.
The advantage of hosting a LEM is being able to invite all your friends-at mine -
my guests were so impressed and were blown away by the projectors and music that they went down the street and purchase beverages for all(twice)- towards midnight my guests called in a big pizza order too. -- If & when I host another i can count of those friends to join us- bring even more friends and help before, during and after the event. We used yellow 'DANGER" tape to show all there the 'danger zones' and where they would be perfectly safe. Evil300 showed us a coll thing- he placed three chairs close together against a wall and aimed his PJ at them- all the effects he was using were 'circles' -

then he had three of our guests put on goggles and he walked them to these chairs- he told them they could take the googles off when he gave them the OK- and that at NO TIME should they get up UNLESS they put the goggles back on.

SO-- they were in the center of a 2W everchanging full color 'laser tunnel' and we had a LOT of fog going on. Circular liquid sky- Everybody got a turn-- that was very cool--
and a super chance to take some awesome pics or vids.

BUT-- as you will or have read in this thread- those unfamiliar with lasers and the effect they can have on digital cameras MUST be warned about possible damage and how to avoid it. Just like you must do for protecting our eyes.


Well-known member
LPF Site Supporter
Oct 14, 2012
Great stuff Hak, as bungy and Clayton have stated, I probably won't be signing up for an LSO class, but this info. is valuable reading for any laser enthusiast; even more so for those who own projectors.
It's also very enlightening to learn about all the complexities involved in putting on a "legal" laser show.
Keep the good info. coming; will be staying tuned to "Hak's LSO channel". :D


Well-known member
Apr 2, 2009
TY Jeff- I have pretty much given up my plan to start a laser show company- like many things in life -what we think and what is fact can be miles apart-+
-There is always more work than fun-

and ATM I would be very happy just working for another show company as a LSO.

-- If enough want- Adam(buffo) may be able to get Casey Stack to come to SELEM 2014 and put on his safety class- it is an intro to the LSO class and is an eye-opener and well worth the low cost to attend. IIRC the fee is somewhat based upon how many want to attend-

Here are some pics from my text book and some illustrations too.



Well-known member
Apr 2, 2009
ready for more??


enLIGHTenment comes when you
know what you don't know.

As mentioned before-- taping shows is good but when attempting audience scanning is a must- it needs to be done.

showing the entire audience and all of the show all of the time... . Greg told us in a few cases those who complained about lasers in the eyes were actually lased by someone in the audience who did the common practice now of bringing a laser to a laser show-IMHO its a huge overesight to NOT take control of the venue and take whatever measures may be needed to prevent anyone 'else' operating a laser.--

I was at one event where an announcement was made that let all know the show will be stopped if need be.
I had already seen a few before the concert began- but none after that--


Initial laser operation
CHECK- (no non essential people)
ANNOUNCE- 'lasers are coming on' ..'do not look at beams!'
This still needs to be done at the lowerst/safest level possible.
if you can see you are hitting your tragets -mirrors etc
....then you do not need full power for that.

Check again for termination on the master shutter/attenuator.(when in the closed position)
For systems w/ LUMIA or beam tables: aiming must be done one at a time- you must see where the beam terminates- 'walk' the beams into position slowly- ONLY then should you have someone re-aim the bounce mirror for the desired target.

Scanner systems
Start w/ small angle with low power-
carefully work your way up to the desired angle-& not exceed the desired area.
Once set- no new changes should be made.

after all is set & 'locked down' mask the opening allowing only enough to hit all targets- and NO overfill.

final Power-up
proper termination-
room and stage lights set low (for now)
re-check for non essentials
increase all lights to brightest level-
or unwanted laser light.
for outdoor shows.. do the same plus verify all beam directions and angles to match Show plan/report(already submitted to the FAA)

Set for show

stop everything and make NO changes -
nothing gets turned on or moved.
If possible just before the area is opened to the audience check once more
check for beam path(s) =clear- announce- bring laser show up slowly to confirm all tagets or areas have NOT changed.
( YEAH I feel ya- if its done right there is a lot of work-

****************************************************************** (page 25)


They are a must when the built-in safety features will not be enough.

IMO its better to wear them needlessly 100 times than forget the one time that can cost you an eye.

anything requiring you to both enter the PJ and have it on, are some of those times.
Expect to pay ~$300 for the best that cover all wavelengths.

note_when possible do any jobs you can with the power level at its lowest (not possible w/ttl iirc)
Only well trained people should be aligning class 4.

Laser wavelength at which protection is afforded. _OD

Expressed in the following formula:

OD = log 10 (Ei/Et)
Ei = beam irradiance (w/cm2) for a 'worse case exposure"
Et = transmitted beam irradiance (MPE limit in W/cm2)

Example: OD of 4.0 allows 1/10,000 of the laser light energy to be transmitted.

For any given laser:
(a) calculation
(b) consulting nomograms or tables (e.g. ANSI 136.1 guidelines), or
(c) consulting the laser manufacturer.
damage will decrease protection
Damage threshold is max protection at least 5-10 seconds following noticeable melting or flame.
LSE = Laser Safety Eyeware

Spectator control
Your setting up is not a spectator event- as most have little idea of what is safe- again clear all non -essentials(completely) and announce.- This I am told is a big problem-- workers and their friends-

Service personnel

The LSO should make sure only qualified individuals with proper training to do service on laser products.

Working in pairs (buddy system) is a good idea- lots of danger-- at all times.

after service the LSO needs to recheck all safety control measures- no exceptions.

)))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) more later
Jan 13, 2010
Thanks Len for posting all of this. Even if 99% of everyone who ever join never have intentions of attenting a LSO course. This information is still valuable as many things could be learned from it even for DIY hobby use. If O could rep you 10 times I would Len as this isfantastic info.


Well-known member
Apr 2, 2009
TY Jeff

People get 'turned in' for unsafe shows more often than one thinks.
many times its acameraphone YTube vid naming names places and dates- showing lasers in faces.

AND if the gig ONCE belonged to another that may be one reason some make calls to the FDA- not the best of reasons but if its unsafe then it is unsafe--I have read of people showing up at clubs flashing their LSO biz card and asking questions. while that may be WAY beyond their authority I am sure if a LSO contacts the authorities they will give the report more credence. This is just one of the reasons less DJs now go with lasers- LED lights have come a long way and are safe in comparison- big ass plasma screens also hurt the laser show companies== I must admit the High Def is awesome.



Well-known member
Apr 2, 2009
Sorry I had to back burner this thread for A BIT-
Its still far from complete -- As you can imagine-- the 'regular' course (~$1500) goes on for nearly three days-- So at SELEM its crunched down to 6 hours or so.
IF you are thinking about both SELEM and the LSO its best to join and PM SELEM head honcho Adam (buffo) -- He , of course has been a LSO for a long time and we may get some info posted here when he can find the time--- aside from the mountain of work for SELEM he also does FLEM (last month) as he has family there as well as in NC.(IIRC)
making either of these LEMs is a must if, you too, would like to HOST a LEM near your location- minimum number of attendees is 2- There are very few tricks to doing a successful LEM that Adam does not know- he has given me the 'tools' to be a good host and for that I am very greatful..

IF you are wanting to do SELEM i cannot stress enough about doing your best to both arrive early to assist in the set up and also staying after to help load all that gear back up-- doing that will make up for any lacking of your own gear-- and even if you own NO projectors you should go and plan to be a good helper.

FYI Many 'Pros' who come to SELEM are giving up that entire week from doing any shows-- so instead of making some money they are spending a lot-- and lending these guys a hand is a good way to say thanks..just keep asking what needs being done----

it may NOT be what you WANT to do at a LEM--

BUT will be what you should be doing.--

hak's dos centavos solo
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New member
Jan 27, 2008
Re: ILDA's Laser Safety Officer (LSO) course

Good post Len. I completely agree with your statements regarding LSO certification - it can make the difference between landing a gig and being passed over for someone else. But more importantly, even if you never plan to do commercial shows, having the LSO certification is a very good thing. It changes the way you look at lasers and laser projectors, and it is a definite plus - even for a hobbyist.

The class isn't going to teach you all there is to know about laser safety. That would take years. But what it does do is open your eyes to things you may have never thought about before. It stresses the fact that you can't rely on intuition when it comes to laser exposure; you *must* run the numbers to be sure. And of course, the class shows you exactly how to do this.

As an example of something that is counter-intuitive, consider this example from the class I took: A 4 watt CW DPSS green laser is aimed at a wall. The spot is 6 mm in diameter at the wall, and the operator is viewing the spot from a distance of 15 inches away with no eye protection. Is this eye-safe?

Believe it or not, the answer is yes. Although it would surely be painful to observe something that bright (especially at such a close distance), when you run the numbers for a diffuse reflection at that distance and power level, you are actually below the MPE - albeit just barely.

One of the goals of the class is to inform people about things that they might have never even thought about before. Such as: You're setting up for a show and the fire marshal decides that your lasers might pose a fire hazard. How do you prove otherwise? Well, in the LSO course they cover the NFPA standard, which has a section that deals specifically with laser light shows. What better way to put a fire marshal at ease than to quote chapter and verse from the same standard he's already used to using?

When you are finished with the class, you may not know everything about laser safety, but you have a good foundation to build on. More importantly though, you will be aware of things that you need to check on, even if you can't remember them off the top of your head. You'll also have the tools to find the answers you need. And that's very important, because every situation is different.

Finally, a few corrections. The ILDA LSO class is normally a 10-12 hour course. They have split it up over two or three days in the past during ILDA conferences to allow time for people to enjoy other activities during the day, but that is more out of consideration for the guests than anything else. And the cost has always been between $450 and $500. (ILDA members get a $50 discount.)

The 3-day, $1500 classes that Len mentioned are offered by Raytheon and Coherent, and they deal mostly with industrial laser applications. They are not really applicable to light show uses. That's why ILDA came up with their own course curriculum. It's geared specifically to laser light show applications.

Finally, as Len mentioned, right now we don't have anyone signed up for the LSO class for the Monday after SELEM. We would need at least 6 people to sign up in order to hold the class. Greg Makhov from LSDI in Orlando has already confirmed that he is available to teach the class though, so if there is enough interest then we will definitely host the class again.

See you guys at SELEM! :)



Well-known member
Apr 2, 2009
Thanks Adam --especailly the much-needed corrections-

The learning never stops for a LSO-- unique set-ups can happen and you had better be able to do the research and ask help from friends to make sure you have everything done right. It seems that no testing is ever done only once. We heard stories about shows where the LSO did not get the cooperation needed from other crews working in the same areas..
and ones where things got changed that effected the laser show in very bad ways.

You just cant trust that your set up done the day before will still be the way you want it- so every time (--at low power) testing one more time is a must.

More from the class going up here asap.
-- There is a lot more coming...


Well-known member
Apr 2, 2009

in the next weeks i will be finishing up this tut and taking my LSO exam-

I will have some math questions to share- they have (IIRC) 3 of them after ther 40 Qs-
they are 'extra credit' math Qs that help if you missed too many but wont hurt in any way-wrong or unanswered--
I will post the links to the calcs. used to do these w/o be a math wiz-


BTW I have a thread going in the WELCOME section 'ANYONE OWNING A POINTER...)
AND there are t wo quizzes linked there and please do post your thoughts to keep this thread near the top- (OR if one of you wants to---ask admin for a sticky on this one)

Im the OP and dont feel i should be doing the asking-i am NOT like TJ in that respect--



Well-known member
Apr 2, 2009
HOW and WHO is responsible for safe shows??

Basically there are three one being the LSO- and the other two are Managers and Operators--

first management duties-
designate a REAL LSO- and they are in charge of safety program and the operators who control the show. All new employees aof a laser show company must ]be trained and tested to assure they know the job in detail.
So management eenures that the show-the gear are properly varianced and ALL requirements (Licensing/regs)are met & that the LSO has been trained and has enough experience with the equipment and safe use,





and operation of the laser show

IF needed the LSO is rwequired to stop any show not done in a safe manner-
( this can be very hard to do when dealing with those NOT laser savvy)
so ALL sources of radiation with a varianced show syste, . holder of variance or LO
(Laser Op)

the LSO msut see that all regs are met for public usage.

Only qulified personal may work on gear or show

any service or maintence is perfromed by qualified personal

and approve or reject such.(both gear and personnel)

all 'incidents' must be investgated, documneted and reported in detail.

see that proper eyeware and other forms of protection are used and understood-

the LSO is the Company safety trainer- and must be able to train those in need.

all new opertors must be trained for thier duties on the job.

the placeing and selection of PROPER signage and physical controls

The preformance of laser radiation analyses- venue surveys- show reports and other paperwork and show diagrams.

all laser under the control of the LSO needs to classify or verify the lasers being controller

in both controlled and incontrolled areas the LSO must evauakte the hazards

and a hard one-- evaluate & consider any conditions . client demands or other elements of the set-up that might increase the danger


the Responsibilites of the LO

they do the show checklists after set-up
they are responsible for the alignments and proper set-up
the LO 'runs' the show and needs to be in control at all times
and the LO must be sure all is working safely after sewrvice maintence or re-alignment


Injury from electrical source is a more common injury that the lasers themselves-
so both the LSO and the LO must be viligent about the safety of working around high voltages- and be trained and ready to help in the case of an accident-

LOs or workers in dangerous areas that may expose them to radiation from Class 3B or Class4 need to have regular baseline eye examinations at least every two years of working with lasers-as well as an exam after any icncidents.


CPR and laser shows

its a good idea to have all personal trained for CPR,
and keeping track of such training ocs is another job for the LSO