Honest Review: Spartan BP 40mW V.3 w / LPT

[phoenix77]

If I remember correctly from Algebra & Mathematics when I was back in high school (Back in '69-'72) in order to get an average, one must add up all the figure values, then divide by the total of figures. ex; readings, 2-4-6mW's, added together=12mW's 2-4-6=3Figures so, take the 12mW's & divide by the 3 figures & that will = 4 answer. At least thats the way I was taught to take an average, whether that kind of Math works here, will have to be decided by brainier minds than mine. Just tried to help. phoenix77/rob

 

[VW]

Thanks. Yeah I remember a bit of that now, kind of like the range and meduim. However I'm clueless as how to get the right figures required for pin pointing an average.

 

[Helioplasma]

Eye are sensitive to light intensity variation at 40 Hz Tops. When moving around you don't even see your light bulbs flashing on and off at 50Hz, so if you have a 2 KHz flashing laser, I highly doubt your eyes will percieve the variation, but the camera does on long exposure.

 

[VW]

Eye are sensitive to light intensity variation at 40 Hz Tops. When moving around you don't even see your light bulbs flashing on and off at 50Hz, so if you have a 2 KHz flashing laser, I highly doubt your eyes will percieve the variation, but the camera does on long exposure.

Do you mean the variation of power? Or the variation of pulses?

 

[millionaire]

Very nice laser you have there. The outputs seem to slowly fluctuate but thats not bad. Umm isnt htis advertised as the strongest blue laser there is right. Well the optotronics makes a 35 mW CW laser which isnt it more powerful than a pulsed one? and ive seen a CW rpl blue hit 82 mW peak and i cant remembered what it averaged but can you really compare a pulsed laser to a non pulsed for power wise?

 

[VW]

Very nice laser you have there. The outputs seem to slowly fluctuate but thats not bad. Umm isnt htis advertised as the strongest blue laser there is right. Well the optotronics makes a 35 mW CW laser which isnt it more powerful than a pulsed one? and ive seen a CW rpl blue hit 82 mW peak and i cant remembered what it averaged but can you really compare a pulsed laser to a non pulsed for power wise?

Kind of missleading, I know. I think the logic of it is that they sell the highest rated mW for 473nm, I.e "the most powerful."

As for fact, it's debatable. The only way I would ever know is to have them both side by side and test them properly, unbiased. I'm pretty confident the RPL would shine victorious, but not without a challenge. I tested this laser with a thermal unit, meaning the heat measured by this laser was what I discribed. That includes it's 50/50 duty cycle, meaning each pulse would generate roughly 80mW. With brightness, again that would be down to thorough comparison. From what I gather by other people's posts, 2000Hz is fast enough for the eye to not detect the pulsed action mid beam. However to me this is speculative as it can clearly be seen when drawn across a wall, so yeah, only comparison can tell. The RPL's divergence would make an unfair advantage on brightness, but that's a flaw on the Spartan's part, so it's all fair game. As for burning, I have no idea. Again divergence would help the RPL here, but with a lens, a bit of patience (got to respect it's slow power climb) and full power I'm sure the Spartan will have no problem burning.

If I only had $1200...

 

[millionaire]

[quote author=millionaire link=1212168225/12#20 date=1213227304]Very nice laser you have there. The outputs seem to slowly fluctuate but thats not bad. Umm isnt htis advertised as the strongest blue laser there is right. Well the optotronics makes a 35 mW CW laser which isnt it more powerful than a pulsed one? and ive seen a CW rpl blue hit 82 mW peak and i cant remembered what it averaged but can you really compare a pulsed laser to a non pulsed for power wise?

Kind of missleading, I know.  I think the logic of it is that they sell the highest rated mW for 473nm, I.e "the most powerful."

As for fact, it's debatable.  The only way I would ever know is to have them both side by side and test them properly, unbiased.  I'm pretty confident the RPL would shine victorious, but not without a challenge.  I tested this laser with a thermal unit, meaning the heat measured by this laser was what I discribed.  That includes it's 50/50 duty cycle, meaning each pulse would generate roughly 80mW.  With brightness, again that would be down to thorough comparison.  From what I gather by other people's posts, 2000Hz is fast enough for the eye to not detect the pulsed action mid beam.  However to me this is speculative as it can clearly be seen when drawn across a wall, so yeah, only comparison can tell.  The RPL's divergence would make an unfair advantage on brightness, but that's a flaw on the Spartan's part, so it's all fair game.  As for burning, I have no idea.  Again divergence would help the RPL here, but with a lens, a bit of patience (got to respect it's slow power climb) and full power I'm sure the Spartan will have no problem burning.

If I only had $1200...[/quote]







im definatly not putting ur laser down in fact im very jealous its just that im wondering what one would burn better nothing against ur laser cause you normally dont get blues for burning there to look at and then CW and pulsed doesnt matter cause it will seem the same its just me wondering out loud.

 

[VW]

[quote author=VW link=1212168225/12#21 date=1213231111][quote author=millionaire link=1212168225/12#20 date=1213227304]Very nice laser you have there. The outputs seem to slowly fluctuate but thats not bad. Umm isnt htis advertised as the strongest blue laser there is right. Well the optotronics makes a 35 mW CW laser which isnt it more powerful than a pulsed one? and ive seen a CW rpl blue hit 82 mW peak and i cant remembered what it averaged but can you really compare a pulsed laser to a non pulsed for power wise?

Kind of missleading, I know.  I think the logic of it is that they sell the highest rated mW for 473nm, I.e "the most powerful."

As for fact, it's debatable.  The only way I would ever know is to have them both side by side and test them properly, unbiased.  I'm pretty confident the RPL would shine victorious, but not without a challenge.  I tested this laser with a thermal unit, meaning the heat measured by this laser was what I discribed.  That includes it's 50/50 duty cycle, meaning each pulse would generate roughly 80mW.  With brightness, again that would be down to thorough comparison.  From what I gather by other people's posts, 2000Hz is fast enough for the eye to not detect the pulsed action mid beam.  However to me this is speculative as it can clearly be seen when drawn across a wall, so yeah, only comparison can tell.  The RPL's divergence would make an unfair advantage on brightness, but that's a flaw on the Spartan's part, so it's all fair game.  As for burning, I have no idea.  Again divergence would help the RPL here, but with a lens, a bit of patience (got to respect it's slow power climb) and full power I'm sure the Spartan will have no problem burning.

If I only had $1200...[/quote]







im definatly not putting ur laser down in fact im very jealous   its just that im wondering what one would burn better nothing against ur laser cause you normally dont get blues for burning there to look at and then CW and pulsed doesnt matter cause it will seem the same its just me wondering out loud.
[/quote]
I'm wondering also, just throwing my thoughts out there.  Like I say though, the RPL has divergence at 1.0mrad, so it should always be better at burning if power was equal...

 

[Deleted member 10578]

Hi VW,
To get an accurate idea of the Spartan's duty cycle, could you post another picture taken at a much fast exposure.
The pictures on here are too long of an exposure to get a measurement.
Try doing an exposure of 1/200 or maybe even faster, while at the same time moving the beam across the frame in one or two quick passes. The idea is to get a picture that clearly shows the on/off cycles.

You can then easily measure the duty cycle by measuring the distance on your monitor from when a pulse turns on to the point it turns on again, this is the period of the cycle. Then measure the distance from when the beam turns on until it turns off, this is the "on" time. To get the duty cycle, just divide "on time" by the period to get the duty cycle.
I saw you have a pretty nice thermal head and meter, but you need to check it's specs to see if it's capable of accurate measurement pulsed lasers and if so what the fastest pulsed laser it can accurately test.

Thermal heads have a response time in that it takes a certain amount of time for the detector to fully respond to a pulse as well as how long the head takes to respond after the pulse is removed; much like the human eye cannot see the pulses as they are faster the eyes response time.
The best way to measure this would be to use a meter that records peak values, like the laser check provided you make sure the IR is filtered and removed beforehand. With the peak value in hand, just multiply the peak by the duty cycle to get the average output power.

One note I wanted to add about pulsed lasers.
It's true the most powerful lasers in the world are pulsed and that's because it's easier to make a laser that can output a megawatt for for a few pico-seconds than to make on that can do it continuously. The same goes for pointers as well, it's easier and cheaper to make an xxxmw pulsed pointer than a CW of the same power.
As far as burning power goes, continuous wave is going to always be more pwoerful as there is no "off" period for the target to cool down so to speak. (btw, I'm not commenting on the Spartan here, just CW vs pulsed of any type/wavelength).
Some people have commented that as long as the pulse frequency is faster than the eye can detect, it doesn't matter for pointer visual brightness, but that too is not true. Even though the human cannot detect on/off switching of these pulses, the eye will detect a difference in brightness as the duty cycle changes from 50% to 100%. Take a light dimmer for instance, most of these work by decreasing the duty cycle of the AC house current with the use of a triac, the frequency of the AC doesn't change, just the duty cycle and with the decreased duty cycle, the dimmer switch reduces the brightness of the light bulb even though the on/off frequency remains higher than we can dectect.

Jack

 

[VW]

I have no idea how to get a different exposure on this camera. Thanks for the good insight though. As for the average, wouldn't that just give you the peak power per pulse? Not the average power over a set period of time?