match light at 215 Feet

[Morepower]

Sorry to say I'm not wowed like the rest. This isn't a 215 foot match light. It is a 12 inch match light since the magnifying lens is a short distance from the match. The setup is no different than what is done with a magnifying lens and the Sun lighting a match. Nobody would call that a 93 million mile match light, would they.
In order to qualify the lenses used to expand the beam and focus the beam would have to be close to the laser and the match would have to be 215 feet from the point where the last lens in the setup is positioned.

While what you are saying is true I think it is still a good demonstration showing that the Laser's Beam dosn't loose any negligible amount of power over distance.

 

[stevetexas]

Sorry to say I'm not wowed like the rest. This isn't a 215 foot match light. It is a 12 inch match light since the magnifying lens is a short distance from the match. The setup is no different than what is done with a magnifying lens and the Sun lighting a match. Nobody would call that a 93 million mile match light, would they.
In order to qualify the lenses used to expand the beam and focus the beam would have to be close to the laser and the match would have to be 215 feet from the point where the last lens in the setup is positioned.

I am not arguing the point. BUT, check out the diameter of YOUR lasers dot at 215 feet. I bet it wouldn't even fit into a 3" magnifying glass - anything that doesn't fit inside the magnifier you're using is "lost" for burning power. My beam diameter doesn't hit 3" until about 350 feet (roughly). So I could, with the same magnifier, easily light a match there as well.

I could probably light one up to 500 feet and will try it later this week. (The beam diameter should be about 4" diameter at 500 feet, my magnifier is 3" diameter) So assuming a rough estimate of 75% of the original 4" beam (and 240 mW output) is collected by the 3" magnifier I should have 180 mW to work with...

Even a low divergence unit (approx 1.25 mRad) grows to the 3" diameter mark at 200 feet - any distance over that and you'll lose power.

Steve001:
I never claimed a record, or asked you to be wowed. I also stated it wasn't a record, so hold off on the hostilities. I just wanted to show you what was possible. If you don't like it, don't try it. Pretty simple. :

For the rest who are interested, I'll try a match light at 500 feet with and without the beam expander.

 

[Gazoo]

I don't care what anyone thinks...LOL. Call me a wower or whatever.. ;D I am still very impressed.

Stevetexas, please keep us posted on your findings as you increase the distance. This is an experiment I could get into a little later on. I find what you accomplished to be very interesting

 

[pseudonomen137]

I am not arguing the point.  BUT, check out the diameter of YOUR lasers dot at 215 feet.  I bet it wouldn't even fit into a 3" magnifying glass  - anything that doesn't fit inside the magnifier you're using is "lost" for burning power.  My beam diameter doesn't hit 3" until about 350 feet (roughly).  So I could, with the same magnifier, easily light a match there as well.  

Oh don't make me pull out the RPL!

Anyway, I feel like getting into some fuzzy math here:

Assuming the 4" figure you give is the 1/e^2 spot size diameter (a standard spec which means that ~86.4665% of the total power is enclosed within that spot [to be precise: (e^2-1)/e^2]), the 3" diameter spot would contain ~67.53% of the 240mW would be contained - 162mW. If you dropped down to 2" you could still retain 94.4mW or so, and 28.2mW at 1" of that 4" spot diameter.

 

[Daedal]

Pseudo never fails to display quite a bit of into in a very little sentence... ;D

Nonetheless and regardless of what other may say... Lighting a match from such a distance regardless of using a lens or not is very impressive! Keep us posted on the outcome of the 500ft match light Steve, and great work.

Thank you;
DDL

 

[stevetexas]

Pseudo - what are the beam specs on the RPL?? Power?

I'd love to see another long distance match light without a beam expander!!!

Thanks,
Steve

 

[steve001]

[quote author=steve001 link=1185079181/0#13 date=1185197667]Sorry to say I'm not wowed like the rest. This isn't a 215 foot match light. It is a 12 inch match light since the magnifying lens is a short distance from the match. The setup is no different than what is done with a magnifying lens and the Sun lighting a match. Nobody would call that a 93 million mile match light, would they.
In order to qualify the lenses used to expand the beam and focus the beam would have to be close to the laser and the match would have to be 215 feet from the point where the last lens in the setup is positioned.

I am not arguing the point. BUT, check out the diameter of YOUR lasers dot at 215 feet. I bet it wouldn't even fit into a 3" magnifying glass - anything that doesn't fit inside the magnifier you're using is "lost" for burning power. My beam diameter doesn't hit 3" until about 350 feet (roughly). So I could, with the same magnifier, easily light a match there as well.

I could probably light one up to 500 feet and will try it later this week. (The beam diameter should be about 4" diameter at 500 feet, my magnifier is 3" diameter) So assuming a rough estimate of 75% of the original 4" beam (and 240 mW output) is collected by the 3" magnifier I should have 180 mW to work with...

Even a low divergence unit (approx 1.25 mRad) grows to the 3" diameter mark at 200 feet - any distance over that and you'll lose power.

Steve001:
I never claimed a record, or asked you to be wowed. I also stated it wasn't a record, so hold off on the hostilities. I just wanted to show you what was possible. If you don't like it, don't try it. Pretty simple. :

For the rest who are interested, I'll try a match light at 500 feet with and without the beam expander.
[/quote]


I was not being hostile sheesh people can't take a criticism.
Did you know that it can be done. By first expanding again the beam then focusing the beam at mid distance to the target, this will make the beam the same diameter as it is at the aperture when it reaches the target. Example if the beam is expanded to 1.3 cm at the lens and focused at 500m it will at 1000m have the same diameter as it did at the the lens- 1.3cm. So if you try this you should be able to light a match midpoint. See what the maximum focal distance is for your beam expander.
The original optics within the laser expand the beam then collimate the beam, by adding another beam expander you've extended the range to which the beam can be focused. Experiment. You'll need lenses with diameters at least 3 times larger than the beam. Do you follow what I've said

 

[Frosty]

lol I dont know if I follow all this but i gotta say that is cool!

Now go out to where the match was and put a mirror in its place, bingo theres your 500 feet then you get to be right next to the laser too. I gotta admit Steve001's idea is pretty neat expanding the beam then refocusing it at some crazy distance!!! awsome!!

 

[larrymz3]

Wow, interesting thread!

 

[Hemlock_Mike]

Steve --

You Cheated ??? NO -- You used optics and experimented to push the limits of the hobby That's why we're all here. How far can we push a diode --- how can we combine two beams -- etc etc?????? I know that none of my "pointers" could do that --- WELL -- I do have a 10" fresnel lens .... Hummmmmm

Mike