Help a noob out...

[firefox335]

I am looking for a green laser pointer to build a "light sculpture" on my ceiling. I need something with a very visible bright beam. I am not interested in cutting plastic, lighting matches or popping balloons, I'm just looking for the beam to be visible in the room under normal light. Can someone recommend a decent green laser pen in the $50 price range? I'd prefer a constant on. Maybe 100-150mw. Whadda ya think?

 

[kiyoukan]

for something that is going to be on for a long period of time you are not going to want a pen you will want a lab style.
aixiz make a 100mw one if i remember that happens to be often over spec meaning its power is around 130mw.
They can be on for long periods of time.
but i think their price is around 100$

 

[aryntha]

I honestly think 100-150mW may be a bit high for something like that... We get really 'relatively' fooled by these ultra powerful lasers lately.

Really I think 30mW would be fine for something like that.

 

[kiyoukan]

he said under normal light and my green is a bit visible at around 60mw but not enough for a nice visible piece of art, you want it to be noticed not dim.
Unless you want to use fog you will want around 100mw of green

 

[Crazy Jay]

I see this common with lack of understanding... to see a beam in daylight or a lit room you would NEED the higher powered lasers that melt plastic and pop balloons.

 

[kiyoukan]

so 100-200mw lab green should be what hes after correct?

 

[chipdouglas]

I'm a bit confused. Is he wanting to see the actual beam make a shape like a sculpture or does he want a scanner/spiro so he can get an image on the ceiling? if the latter then 30 mw is plenty. if the first then i don't think that will be possible.

 

[firefox335]

Thanks for all of the replies. Well, I'm wanting it to be bright. And I guess I'm just looking for something I can bounce off small mirrors that I can mount to the ceiling to create some kind of abstract crisscross pattern. As I said, I'm not interested in burning, but if a 100-200mw will be bright enough, the fact that it can burn is okay. I guess I would just be worried about the final destination of the beam as I don't want to set the house ablaze. What should the beam eventually hit? A cinder block? I am not oppose to a lab laser, but I will probably get a pen style first to try out my placement of mirrors.

Yes, I am ignorant. That's WHY I came here. If I was an expert, I would not be asking these questions. :thinking:

 

[TheRunner]

Welcome to the forum.I hope you are finding everything you need here.

As for your question, if I understand correctly, you are going to use a laser above everyone head, to make patterns with the beam, like a box or something.

If that is true, it will only be 2 dimensional, not a hologram or anything. Also, in order for the beam to be visible in conditions you are describing (regular lighting, BRIGHT beam) you would have to use fog, or use a laser so powerful, it would be a fire hazard. Or, you could turn the lights off/ dim them, and that would be the brightest way to get a beam.

Good luck.

 

[chipdouglas]

Thanks for all of the replies. Well, I'm wanting it to be bright. And I guess I'm just looking for something I can bounce off small mirrors that I can mount to the ceiling to create some kind of abstract crisscross pattern. As I said, I'm not interested in burning, but if a 100-200mw will be bright enough, the fact that it can burn is okay. I guess I would just be worried about the final destination of the beam as I don't want to set the house ablaze. What should the beam eventually hit? A cinder block? I am not oppose to a lab laser, but I will probably get a pen style first to try out my placement of mirrors.

Yes, I am ignorant. That's WHY I came here. If I was an expert, I would not be asking these questions. :thinking:

30 mw should be fine. but you will need to light some insence. If your ceiling is white you dont want to go to bright cuz th reflection might wash out some beam. also you will need a labby for constant on. Also you will want some front surface mirrors so you get the cleanest bouce off possible. you can make your own out of old hard drives.

michael

 

[firefox335]

Thanks for all of the suggestions. How long can a lab laser be left on at a time? And what are front surface mirrors?

 

[millirad]

Lab lasers with sufficient cooling and driven at a lower power than they are capable of delivering can be left on nearly 24/7. I'm not understanding why you wouldn't just put it on a wall timer though and give it a break for a few hours every day. ;-)

 

[qumefox]

Front surface mirrors are just that. Mirrors with the reflective surface on the front.

Normal general use mirrors have the reflective surface on the back with a layer of paint/epoxy over that, so the glass protects the reflective layer from the front and the paint protects the back side. These work fine for fixing your hair etc, but they're horrible at bouncing beams. The reason for this is that you actually have two reflective surfaces. The surface of the glass itself is reflective, and so is the silvered layer. This results in two spots getting reflected off rear surface mirrors, as well as lots of power loss due to internal reflections inside the glass itself.

Front surface mirrors have the silvering on the front of the glass, therefor only have one reflection surface. However they're more expensive than normal mirrors, and also more fragile, since it's not hard to damage the silvering since it's exposed directly.