Safe crowd scanning mw?

[crazyhobo]

I'm thinking about getting one of the cheaper DinoDirect projectors that has a sound active mode. What is the max mw that would be safe to point towards people? I know it depends on the angle, distance, and pattern too, but what is a ballpark mw? Thanks in advance guys.

 

[Guyfromhe]

Crowd scanning is a super touchy subject and you need to do A LOT of math.. It's not so much the mw rating itself but the power density on the pupil and that changes based on distance and beam size scan speed and a zillion other factors... It's not something you want to do with a cheap projector that doesn't have interlocks, scanfails, beam blocks, attenuation zones and so on and so forth. It's illegal in many countries and not recommended. I would say if you need a mw number to keep under I'd say 5 mw being the absolute MAX for just random crowd scanning since a 5 mw laser is considered eye safe for brief exposure.. You would need a LPM to confirm it was not going over 5 mw and it would probably be too dim to get the effect you wanted.

 

[andy_con]

crowd scanning factors need to cal the MPE level

module power
beam spec
distance

 

[Guyfromhe]

crowd scanning factors need to cal the MPE level

module power
beam spec
distance

Yea MPE was the word I was looking for

 

[crazyhobo]

That's what I was afraid of. Thanks.:yabbem:

 

[Guyfromhe]

Yeah it kinda sucks but it's not worth hurting someone for a show.. I had a few (2) friends in my basement and we were dancing in the fog/laser lights (at eye level -.-) but we all knew to make sure that no one faced towards the laser (we all understood the risks and took appropriate precautions and no one got a beam in the eye) and everyone was fine. I wouldn't trust more than a few people though or people I didn't know extremely well. When I had an actual party the laser was about 30 feet up and like 100' from the crowd projecting onto some trees in my yard no lower than 10 feet off the ground.

I had the fog running so you would get the beam show effect looking towards the laser but no one could get a beam in the eye.

 

[Guyfromhe]

BTW I have one of those cheaper Dino projectors and they are freekin awesome! (Check out my review on the Reke 500RGB in the reviews section)

 

[crazyhobo]

BTW I have one of those cheaper Dino projectors and they are freekin awesome! (Check out my review on the Reke 500RGB in the reviews section)

Funny you mentioned that - it was that very review that led me to ask! I'm really considering buying that exact model.:drool:

 

[ARG]

Funny you mentioned that - it was that very review that led me to ask! I'm really considering buying that exact model.:drool:

If you are, leave it in your cart for a week or so, eventually dino will send you a coupon for 10$ saying you have pending items in your cart, at least they did for me.

 

[Guyfromhe]

I think dino10 will give you 10 percent off..
I got a popup with a 15 percent off code when I was surfing their site when I placed my order...
I also have a 60 dollar cash coupon I'd be willing to part with for like 35 bucks if your really looking to pull the trigger...save you another 25 bucks on it...

They have some even cheaper ones in the rgv and rg/y range but I think the rgb is the sweet spot.. I honestly have nothing bad to say about tht unit based on what I paid for it... The other 4 people I convinced to buy them should be getting theirs this week if you want to wait for others opinions on it and I should be getting my DAC this week too... I want to do an audience scan but where all the beams are pointed at the floor like a moving sidewalk or runway effect and since it will be on the ground no one can get it in their eyes... Other than a weird scan failure it should be safe I think... not that I'm going to be doing a public display or anything...

 

[Benm]

These units are -strictly speaking- not suitable for crowd scanning even if you do the MPE calculations... they lack safety features such as a mechanism to shutdown or block the output if one or both scanner mirrors gets stuck in a certain position.

 

[Guyfromhe]

These units are -strictly speaking- not suitable for crowd scanning even if you do the MPE calculations... they lack safety features such as a mechanism to shutdown or block the output if one or both scanner mirrors gets stuck in a certain position.

Yes I said that in the my first post:

It's not something you want to do with a cheap projector that doesn't have interlocks, scanfails, beam blocks, attenuation zones and so on and so forth

 

[crazyhobo]

I think dino10 will give you 10 percent off..
I got a popup with a 15 percent off code when I was surfing their site when I placed my order...
I also have a 60 dollar cash coupon I'd be willing to part with for like 35 bucks if your really looking to pull the trigger...save you another 25 bucks on it...

Oh it will be a while before I can afford it. If I do go with it I'll see if you still have that coupon. :thanks:

 

[Guyfromhe]

It's good for a year I think... I don't really want to buy anything else from them so unless someone else decides they wanted it I will probably have it... anyway just drop me a PM if/when you are interested