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Z-Bolt 3-5 mW BLUE laserpointer?

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#1 Stefan Rostyne

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Posted 14 November 2012 - 10:49 AM

http://www.z-bolt.co...onomy/gx-5.html

Anyone tried these? I am overthinking these as GLP's are pretty useless here, in winter.

The Z-Bolt® Sapphire Galaxy is the product of new design technologies and manufacturing efficiencies. Z-Bolt® Sapphire Series laser pointers are fabricated with InGaN semiconductors, which emit blue laser light without frequency-doubling. Blue laser is eye safe - IEC Class 3R and FDA Class IIIa. The BX-5 features true blue 445~455nm blue laser light (not 405nm violet/purple) The new design blue laser module operates on 1 pc CR123A lithium battery (2 pcs included). Projects a brilliant sapphire blue laser beam and dot. Visible beam at night - dot only during daytime hours. Six (6) hours constant on operation.



#2 dan_h

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Posted 14 November 2012 - 11:32 AM

I like blue but why are the green lasers useless in winter? I know that they typically don't work in extreme cold but I thought that is because the batteries fail at low temps. Won't the blue laser have the same battery issues?

dan

#3 Shneor

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Posted 14 November 2012 - 02:38 PM

Yeah, price for this item starts at $188. You can find a 5mw blue laser on Ebay for under $5.

Clears,

#4 Stefan Rostyne

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Posted 14 November 2012 - 03:17 PM

price for this item starts at $188. You can find a 5mw blue laser on Ebay for under $5



$188 ain't cheap; I agree with that. But my first GLP was similar in price. I do, however, feel just as much object on the $5 Ebay lasers. Gettin' what you payed for, and stuff like that.

My question isn't really about pricing, however. Rather just : does it do the job we astronomers expect it to do, or not?

#5 Stefan Rostyne

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Posted 14 November 2012 - 03:23 PM

I know that they typically don't work in extreme cold but I thought that is because the batteries fail at low temps. Won't the blue laser have the same battery issues



GLP's fail because of the optical train shrinking out of collimation, as they are in fact IR pumped. New generation 450nm blue lasers are direct injected diodes, so no IR leaks, and no collimation issues due cold. In fact, they work similar as the old fashion cheap red keychain lasers you find all over.

#6 hottr6

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Posted 15 November 2012 - 08:16 AM

My question isn't really about pricing, however. Rather just : does it do the job we astronomers expect it to do, or not?

I recall reading that the eye is not as sensitive to blue as it is to green, so the GLP will work better than a BLP. This is the reason why RLP are never used as finders. More knowledgeable folk are welcome to correct me.

#7 Jon Isaacs

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Posted 15 November 2012 - 08:44 AM

My question isn't really about pricing, however. Rather just : does it do the job we astronomers expect it to do, or not?

I recall reading that the eye is not as sensitive to blue as it is to green, so the GLP will work better than a BLP. This is the reason why RLP are never used as finders. More knowledgeable folk are welcome to correct me.


I suspect that you are correct. This Wikipedia graph of sensitivity vs color says that at 450nm, the eye's sensitivity is down to less than 5% of what it is in the green.

Wiki Graph: Sensitivity to color

Color Vision

And as you say, more knowledgeable folk are welcome to comment.

Jon

#8 Stefan Rostyne

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Posted 15 November 2012 - 08:54 AM

I recall reading that the eye is not as sensitive to blue as it is to green, so the GLP will work better than a BLP



Well, I found this experience on another forum:

At this power, and at 445nm, a lot of people may be concerned with visibility. After all, we all know that 555nm is the center of human vision - the most "visibility per milliwatt", and that wavelengths in either direction (towards blue or towards red) fall off in visibility from there.

One might think that this means that a 450nm laser appears very dim.

I can assure you that this is not the case

445nm - VISIBILITY AT NIGHT :

Tonight is a clear winter night in Colorado. We're about to go watch the lunar eclipse. When I took my *brandname* outside, I was actually VERY pleasantly surprised at how vividly visible the beam is!

Part of the reason for this is, in laymans terms: while 555nm green may be the peak of our vision during the day (called 'photopic vision'); at night, the center of our vision actually shifts towards blue. This is called 'scotopic vision', and centers around 506nm. When the eye is seeing scotopically, 450nm may appear almost just as bright as 532nm.

So, in some cases, especially at night, 445-450nm may be nearly as visible as, and possibly more visible than 532nm green. Visually, this laser can be described as
quite visible, and the beam at night, even in clear air, is very striking.


and an eye response chart :

Attached Thumbnails

  • 5520756-eye sensitivity.png


#9 Stefan Rostyne

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Posted 15 November 2012 - 09:07 AM

This Wikipedia graph of sensitivity vs color says that at 450nm, the eye's sensitivity is down to less than 5% of what it is in the green.



That is correct. It is, however concerning photopic or daylight vision. Scotopic vision (low light situations)
seems to have another sweetspot near 510 nm

another one :

Attached Thumbnails

  • 5520777-eye spectral response.png


#10 Stefan Rostyne

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Posted 15 November 2012 - 09:49 AM

The second graph shows that the scotopic eye is about 50% as sensitive to 450nm light as it is to 532nm (160 vs 320 AVG.REL.SENS.). This would mean that a 5mW BLP will appear half as bright as a 5mW GLP. To me, that may seem like a workable situation, as a true 5mW GLP is often described as being actually too bright, and many of us do prefer 2-3 mW over 5mW.

#11 csrlice12

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Posted 15 November 2012 - 11:16 AM

A simple test: Many electronic devices (especially TVs) have a red/blue led to indicate on/off. On my TV, the "blue" light means off. However, that blue light seems much brighter then the red one, it's not actually brighter, its just that we see blue better then red in the dark.

#12 jtaylor996

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Posted 15 November 2012 - 11:23 AM

Are you sure it's not brighter? I use a lot of guitar pedals on stage, and the ones with blue LEDs are obnoxious to say the least... but it's because they are just brighter than the others. Definitely not dark adapted under stage lighting.

#13 KJL

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Posted 20 July 2013 - 10:46 AM

I've been wanting to post about the Z-Bolt Sapphire Presenter which I purchased last winter, but then life intervened and now I can't do a cold-weather comparison shot! Until next winter, then, here are some salient observations:

1. Z-Bolt's blue lasers use some sort of "real" blue diode, not a pumped design like most GLPs. As far as I know, this sort of blue laser is not easily available on eBay, yet.

2. The Sapphire Presenter does not drop in brightness even when Boston weather fell into the mid-teens. That is, between the moment when I first tried the laser after I left the warmth of my house, and when I turned it on again after it had been sitting outside in the frigid cold unused for over an hour, the beam had the same intensity to my eyes. The GLP had long since called it quits: I could see that it was on by waving my hand in front of the beam, but the intensity was so weak I couldn't see anything in the air itself (my GLP is a Wicked Lasers Core, which is supposed to be regulated).

3. The blue laser's beam is utterly visible in the night sky, even in my Boston white zone and without any dark adaptation. It is definitely useable as a night sky pointer. Curiously, the beam's color is not so much blue as nearly white. It's perhaps about half to a third the brightness of a green laser beam, but together with the more neutral coloring this is actually helpful in that it looks less piercing to passer-bys. I've had people yell up at me (I observe from my third-floor deck) because they think I'm doing something nefarious with my GLP. There has been not a peep from uninformed pedestrians after I switched to the blue laser.

4. This first generation of blue diodes have a fat-tish beam pattern, like a (non-degenerate) ellipse with the width 2-3x wider than the height. I actually thought it looked like a 3mm-wide bar at first, until I looked more closely. This means that the beam is a bit diffuse as it travels into the night sky. You wouldn't mistake it for a "laser beam"-thin GLP. This is part of the reason why the blue laser looks dimmer than the green laser; the other is the fact that our eyes are more sensitive to green.

Hope that helps people with their winter laser pointer woes. Now back to waiting for this humid soup to pass ....

#14 Lee D

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Posted 20 July 2013 - 08:00 PM

The "circadian" curve above may be misleading because it has nothing to do with vision.

If you are seeing color, you are using, at least partly, photopic vision. That means best sensitivity around 550nm. Blue light will scatter more in the atmosphere than green light. That may be advantageous if you are using it to do outreach, since people should be able to see it farther off-axis, but it may make it less suitable as a finder.

#15 jerwin

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Posted 21 July 2013 - 12:18 AM

I use a cheap blue laser I got off amazon in a scopestuff starfinder mount on my dob. http://scopestuff.com/ss_sfind.htm

Worked all winter long in the cold Chicago area. My green laser wouldn't work lower than about 40 degrees. My blue one was perfect every night and is still on the first set of AAA batteries.

I have a slightly better green laser I got off ebay that have the key to lock them in the off position. I typically use it during outreach when people are trying to figure out what my scope is pointing at. The green one is easier for a group to see by far.

For whatever reason some peoples eyes don't pick up the blue beam, and you need to be within 10 or 15 feet of it to see the beam anyway. So it's perfect on a dob or a refractor that puts the normal finder in an awkward position all the time. Since your right next to it, the beam shows up fine. It is more difficult to see the beam in heavy light pollution or during dusk but as long as your eye can see it, it works perfectly in all temperature. I'll never give mine up.

Me and my AP buddy also did some basic field testing. He'd take a 30 second exposure of a given DSO and I'd shine my green and blue laser at it from a pretty close proximity, about 20 feet. The green one would ruin his image even up to about 50 feet. However the blue one he never picked up.

I think the people are saying it's brighter are just thinking about it the wrong way. If you shined the blue laser at the ground your night vision is going to be shot, but I'd argue if you shine a green laser at the ground your going to be in a similar situation. The beam your seeing shining into the night sky is visible, but it's way dimmer than a GLP.

My suggestion to you would be to buy a cheap one to make sure your eye can in fact see the beam, but I'm extremely happy with mine in my back yard and dark sites.

Belgium is a beautiful country, I've been twice about 10 years ago. Some of the best beer I've ever had.

Clear skies to you,
Jim

#16 Lee D

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Posted 21 July 2013 - 12:46 AM

I use a cheap blue laser I got off amazon in a scopestuff starfinder mount on my dob. http://scopestuff.com/ss_sfind.htm

Worked all winter long in the cold Chicago area. My green laser wouldn't work lower than about 40 degrees. My blue one was perfect every night and is still on the first set of AAA batteries.

I have a slightly better green laser I got off ebay that have the key to lock them in the off position. I typically use it during outreach when people are trying to figure out what my scope is pointing at. The green one is easier for a group to see by far.

For whatever reason some peoples eyes don't pick up the blue beam, and you need to be within 10 or 15 feet of it to see the beam anyway. So it's perfect on a dob or a refractor that puts the normal finder in an awkward position all the time. Since your right next to it, the beam shows up fine. It is more difficult to see the beam in heavy light pollution or during dusk but as long as your eye can see it, it works perfectly in all temperature. I'll never give mine up.

Me and my AP buddy also did some basic field testing. He'd take a 30 second exposure of a given DSO and I'd shine my green and blue laser at it from a pretty close proximity, about 20 feet. The green one would ruin his image even up to about 50 feet. However the blue one he never picked up.

I think the people are saying it's brighter are just thinking about it the wrong way. If you shined the blue laser at the ground your night vision is going to be shot, but I'd argue if you shine a green laser at the ground your going to be in a similar situation. The beam your seeing shining into the night sky is visible, but it's way dimmer than a GLP.

My suggestion to you would be to buy a cheap one to make sure your eye can in fact see the beam, but I'm extremely happy with mine in my back yard and dark sites.

Belgium is a beautiful country, I've been twice about 10 years ago. Some of the best beer I've ever had.

Clear skies to you,
Jim

Very interesting report, thank you. Now if your results become dominant, and airline pilots can't see them either, we're in great shape!

#17 Midnight Dan

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Posted 21 July 2013 - 07:40 AM

I use a cheap blue laser I got off amazon in a scopestuff starfinder mount on my dob. http://scopestuff.com/ss_sfind.htm

Worked all winter long in the cold Chicago area. My green laser wouldn't work lower than about 40 degrees. My blue one was perfect every night and is still on the first set of AAA batteries.
...
Clear skies to you,
Jim


Do you have a link to that laser?
-Dan

#18 jerwin

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Posted 21 July 2013 - 01:31 PM

I'm not sure why, but I can't find it on amazon anymore. I see it in my order history, but cannot find it or any others on amazon. This one on ebay is the design that fits in the scopestuff mount.

http://www.ebay.com/...Shipping-Fro...

for $6 it says it ships from NY, so shipping should only take a few days. There are some cheaper that look like they ship straight from China.

Jim

#19 jerwin

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Posted 21 July 2013 - 01:38 PM

Very interesting report, thank you. Now if your results become dominant, and airline pilots can't see them either, we're in great shape!


We have a pilot in our local club that reported they were targeted on their landing approach a month or two back. He said it was pretty blinding, but they were also looking towards it trying to assist local police. I think if you briefly shine it on a plane on accident it wouldn't be the end of the world, but I do try to give the sky a second look before I turn it on. This guy the pilot reported was clearly doing following them.

Mine is also a push button design, so it's only on when my finger is on the trigger and I'm aiming, as soon as I'm on my target I release it, so I think there is a pretty low likelihood I'd touch a plane anyway.

Jim


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