Blue laser for astronomy

[vasilas432]

Hi to everyone, this is my first post in the forum!
I would like a blue 445nm high power laser for my telescope. I have searched the web and I would like it to be a quality portable laser. From where do you suggest to buy it and what model?
I have seen the products catalogue from Laserglow and Laserbtb so far.
If you think that blue 445nm isn't appropriate for star pointing, please let me know your thoughts.
Thanks

 

[olympus mons]

Blue is a fairly dim wave length to the human eye and most blue lasers are diodes which mean they don't have as tight and clean of a beam as a dpss laser. You should consider a 532 nm dpss. Best beam in the buisness and as close to peak visible spectrum. They are also quite common so quality ones are not terribly expensive. I believe for star pointing and such you will want between 50-100mW. At least this is what I have read about astronomy laser pointers but IME I would go with 100mW. Unless you're in very dark areas 50mW can be quite faint.

 

[vasilas432]

Hi,
Thanks for your answer!
In Astronomy when you are observing on a dark site there must be no lights to affect your night vision. So it must be a faint 532nm if going green. That's is why I have in mind a 200mw 447nm blue laser. I also read the specs of the laserglow's portable Blue Polaris 200mw one and it says: Operating Temperature Range (°C) -5 to 35. If this correct it can work under low temperature while observing with a telescope.

 

[Trendkilla254]

I have read it is not a good idea to mount the laser to the telescope. Just an FYI.

 

[vasilas432]

I am in Greece,
aircrafts don't fly arround where I observe. Thanks

 

[RB astro]

Hi to everyone, this is my first post in the forum!
I would like a blue 445nm high power laser for my telescope. I have searched the web and I would like it to be a quality portable laser. From where do you suggest to buy it and what model?
I have seen the products catalogue from Laserglow and Laserbtb so far.
If you think that blue 445nm isn't appropriate for star pointing, please let me know your thoughts.
Thanks

Ya-sou Vasilas :wave:
I'm from Australia, parents from Greece. :yh:

I do Astro Photography as my other hobby.
We usually recommend green because it's easier to see, even at low power, like Olympus Mons suggested.
You could use 445nm but it would need really dark skies and using 200mw is getting up there in power.

I mount my green laser directly on my scope, to use as a pointer.
If you haven't got a laser bracket for the scope yet, you can get one on ebay to mount the laser onto.
Laser Pointer Bracket for Telescope Wo William Optics Type Fitting | eBay
This comes with a ring that you can screw down the laser button so it stays on, or leave it off for momentary push button use.

A basic pointer, in the green 532nm would work well.
There are heaps on ebay, do a search.
Or you can buy a cheap set of three colours and see if they suit your location first.
For example something like this:
BMK 3 PCS Green Purple RED Laser Pointer Light PEN 1mW High Power Beam | eBay

Another option is to get a green or red laser rifle scope setup and mount it on the scope.
Again there are heaps on ebay and they come with a continuous button or momentary push button setup.
One example:
Hot Powerful Green Dot Laser Sight Rifle Scope w Rail Barrel Mounts Cap Switch | eBay

I have read it is not a good idea to mount the laser to the telescope. Just an FYI.

We do it all the time, care must be taken for flight paths etc. and not to leave the laser on for prolonged time, always be aware where its pointing.
Vasilas remarked later that he observes at a dark site and no flight paths so it would be ok if he exercises caution.
:yh:

BTW one of my astro images is in my avatar that I took.

RB

 

[olympus mons]

Another option if you have your heart set on blue would be a 473nm dpss 100mW from JetLasers. Down side is they aren't cheap about 300$ and pretty bulky heavy host but an excellent laser. I just bought one a few weeks ago and the color is beautiful and unique.mits also much more visible than 445. It being dpss the beam is very nice with low divergence. But, that being said I agree with Rbastro that green is best suited for your needs and 50mW in a dark area would be very visible. I attended a star and telescope open house night a few years back and one of the people pointing out stars was using a 20mW. It was faint but definitely pointed out the objects he was discussing.

Once you have decided feel free to pm me or ask the community for a good recommendation as to a quality laser pointer. I would advise getting some that has an IR filter for safety reasons as well as to ensure your getting actual true wattage of green light not green and IR which most lower end pointers combine the two wl as their power rating.

 

[Blarg King]

I thought blue light was worse on your night vision?

 

[vasilas432]

Ya-sou Vasilas :wave:
I'm from Australia, parents from Greece. :yh:

I do Astro Photography as my other hobby.
We usually recommend green because it's easier to see, even at low power, like Olympus Mons suggested.
You could use 445nm but it would need really dark skies and using 200mw is getting up there in power.

I mount my green laser directly on my scope, to use as a pointer.
If you haven't got a laser bracket for the scope yet, you can get one on ebay to mount the laser onto.
Laser Pointer Bracket for Telescope Wo William Optics Type Fitting | eBay
This comes with a ring that you can screw down the laser button so it stays on, or leave it off for momentary push button use.

A basic pointer, in the green 532nm would work well.
There are heaps on ebay, do a search.
Or you can buy a cheap set of three colours and see if they suit your location first.
For example something like this:
BMK 3 PCS Green Purple RED Laser Pointer Light PEN 1mW High Power Beam | eBay

Another option is to get a green or red laser rifle scope setup and mount it on the scope.
Again there are heaps on ebay and they come with a continuous button or momentary push button setup.
One example:
Hot Powerful Green Dot Laser Sight Rifle Scope w Rail Barrel Mounts Cap Switch | eBay


We do it all the time, care must be taken for flight paths etc. and not to leave the laser on for prolonged time, always be aware where its pointing.
Vasilas remarked later that he observes at a dark site and no flight paths so it would be ok if he exercises caution.
:yh:

BTW one of my astro images is in my avatar that I took.

RB

Hi, very nice to hear you have Greek parents! Small world, isn't it? I have some relatives in Melbourne
Thank you for the bracket, I couldn't find any and was ready to buy a bracket for a 30mm Finder. You saved me!
Before I become a member here I ordered just for fun a 50mw 532nm with IR filter from Laserbtb. I will receive it in the next few weeks. After that I saw a 150mw 520nm on that site too but it wasn't available to buy it.
I then found Laserglow and started to search for a nice cool laser to have both for the telescope and for playing around. I would have bought their Blue Polaris 200mw portable if my card wasn't blocked due to capital control we still have in Greece. We can buy things but there are some codes that don't pass. Hobbies is one of them. While I could buy from Laserbtb, I couldn't from LaserGlow. I can send money to PayPal personal accounts or pro accounts that are not assigned as hobbies selling. I know it is a joke...

So here I am looking for help! I will probably buy a good 520nm and a 545-573 one. How many mw? I am not sure yet. A strong 532nm will be no good for my night vision. A very strong blue 545-573 maybe won't change the night vision while good on pointing? A good 520nm because I like its color

I have seen on the market section about Sci-Fi laser and Sanwu but I don't know what about them...
Thanks a lot for your help and great photo taken for your avatar!
Vassilios

Another option if you have your heart set on blue would be a 473nm dpss 100mW from JetLasers. Down side is they aren't cheap about 300$ and pretty bulky heavy host but an excellent laser. I just bought one a few weeks ago and the color is beautiful and unique.mits also much more visible than 445. It being dpss the beam is very nice with low divergence. But, that being said I agree with Rbastro that green is best suited for your needs and 50mW in a dark area would be very visible. I attended a star and telescope open house night a few years back and one of the people pointing out stars was using a 20mW. It was faint but definitely pointed out the objects he was discussing.

Once you have decided feel free to pm me or ask the community for a good recommendation as to a quality laser pointer. I would advise getting some that has an IR filter for safety reasons as well as to ensure your getting actual true wattage of green light not green and IR which most lower end pointers combine the two wl as their power rating.

I will look into Jetlasers and 473nm. I am also considering Sci-fi or Sanwu. They both look to have good products. I would like to buy quality lasers and I am not after a cheap solution unless it is both cheap and top notch. I prefer the portable size with the better heatsink anytime. I don't know if those 2 have equal or better quality than Laserglow.
Any help would be appreciated!
Thanks

 

[vasilas432]

I thought blue light was worse on your night vision?

I am not sure, I haven't seen any blue laser in person while dark or whatever light condition.
Thanks

 

[olympus mons]

I thought blue light was worse on your night vision?

I am just guessing but considering in the military we used red lights for map reading in infantry school because red light has the least effect on your night vision I would guess the further wl from 650 would be worse. So 532 would be better than 450? But that's just a logical deduction I could be wrong about that.

I have read in astronomy threads that 650nm would be ideal except they arent very visible and don't come in high enough power while maintaining a good tight beam. Hence, most people use 532's as its the safest and best wl for start pointing.
Another reason I think blue is a really poor choice for star pointing is safety. You would need a very powerful 450 to be able to point to things so the potential for an eye injury is tremendously more with a 500mW 450 opposed to a 50mW 532 with IR filtering. man, i would hate to take a blast from a half watt or more blue laser with my pupil fully dilated from being in the darkness like the OP is describing. Even a 50mW in those conditions would be pretty sever but a half watt? no thank you.

 

[vasilas432]

I am just guessing but considering in the military we used red lights for map reading in infantry school because red light has the least effect on your night vision I would guess the further wl from 650 would be worse. So 532 would be better than 450? But that's just a logical deduction I could be wrong about that.

I have read in astronomy threads that 650nm would be ideal except they arent very visible and don't come in high enough power while maintaining a good tight beam. Hence, most people use 532's as its the safest and best wl for start pointing.
Another reason I think blue is a really poor choice for star pointing is safety. You would need a very powerful 450 to be able to point to things so the potential for an eye injury is tremendously more with a 500mW 450 opposed to a 50mW 532 with IR filtering. man, i would hate to take a blast from a half watt or more blue laser with my pupil fully dilated from being in the darkness like the OP is describing. Even a 50mW in those conditions would be pretty sever but a half watt? no thank you.

I think 450nm blue does not shine enough to destroy night vision. White lights and yellow lights do light pollution. A high power 532nm would shine a lot too. Red lights are ok that's why they are used in the army. Red lights are allowed in Astronomy.
No one is going to have a laser hit while the telescope is aiming at zenith and the laser is on for 20 seconds the most. Also the observation site is located in the dark dessert where there are no people for miles away

 

[blasterman]

Was involved in serious astronomy years ago. A 30mw common 532 green won't affect night vision. Not even close. The problem is you won't find a green with a clickable off/on switch. At least I never did. 445 blues just consume 10x the power to get the same brightness levels. I would look for a 20-30mw lab laser that can be run off a battery.

 

[H2Oxide]

I thought blue light was worse on your night vision?

No, AFAIK blue is just as bad as green, but not worse.

However, blue light is bad for your overall vision. Fortunately, most UV has trouble penetrating our crystalline lens, so it gets absorbed and contributes to cataracts (that can be removed), but blue light can get through and hit our retina and cause AMD, which is much harder to stop, and impossible to cure.

So if you want to be able to observe the stars when you're older, use a green or red laser.

(Using it for pointing in the sky won't hurt your vision, but if you're using it for anything else then get a different color)

 

[Chicxulub]

Without reading the entire thread, I'd like to suggest 473nm DPSS. When using your dark adapted or scotopic vision, one must keep in mind that the peak sensitivity to light is at 505nm. This means that 532 DPSS is 27nm off peak, while 473 DPSS is only 32 off peak. The green would have an advantage mW for mW, but the advantage would be negligible.

Of course, with 473 DPSS comes the tremendous financial issue....

EDIT-

In the military we use dim red lights because the low energy red light doesn't disrupt scotopic vision. If you're using a blue laser in such a manner as to cause the beam to terminate on a wall or something causing a strong splash of light for your eyes to take in (a dot), it would doubtlessly disrupt your scotopic vision and cause you to drop into photopic. However, if you're using the beam to point into the sky to find targets with a telescope, you'll have to be using a laser of tremendous power to get that much backsplash through Rayleigh scattering alone. In this regard, lasers that are as close to 505nm are ideal.

Note- professional observatories use 589nm lasers. This isn't because 589 is inherently better for starpointing as compared to other wavelengths, but because the observatories are already set up to filter the low pressure sodium lighting which is used around them because it emits light at 589nm.

 

[olympus mons]

Note- professional observatories use 589nm lasers. This isn't because 589 is inherently better for starpointing as compared to other wavelengths, but because the observatories are already set up to filter the low pressure sodium lighting which is used around them because it emits light at 589nm.

I'm pretty sure that's not at all correct. They use 589 nm for what's called a laser guide star in an adaptive optics laser system. They use 589 because it excites the sodium atoms in the troposphere 19 kilometers into the atmosphere to create a glowing man made star to use to read atmospheric disturbances.
There not using a 50W laser to point to stars if that's what you meant.