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One might well ask why anyone needs a finder, a Telrad or setting circles? A laser is just another tool that helps us navigate around the sky. 

Many of us are getting a little long in the tooth and don't enjoy the pain of trying to crank our necks to view a red dot or straight through finder or dealing with the field flip and narrow views of a right angled or RACI finder.

A laser pointer has definitely improved my star hopping experience. I gave up on my Telrad  and finder.

Of course I understand the dangers of LP's and those that use them stupidly or maliciously should be punished to the full extent of the law.

But let that not condemn all of us as pariahs.

We all own a knife or a hammer but we don't rampage through the neighborhood stabbing and bludgeoning people. We use them to eat or drive nails.......

I use my laser to aim my scope....

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Proportion and common sense come into this. As others have said, lasers can be a boon for those operations which get harder as you get older. For a quick polar alignment onto Polaris, for instance, just aim one through your polar scope to be sure Polaris will be what you're seeing.  That cuts the knee-grovelling, neck straining time in half. They are also a godsend for showing people around the night sky. 1 Mw is plenty.

Very obviously, there are places and circumstances in which you shouldn't use them and we all know what those are. I don't think this thread should turn into one of those car manuals which tell you not to drink the battery acid.

Olly

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I have family that are pilots and military aircraft crew, they are intentionally targeted by lasers every time they fly but it's really hard to hit a fast mover, a helicopter is possible and they get it all the time. It's not difficult to use a green laser safely if you are mindful. They are very dangerous to eyeballs on the ground and are used effectively by bad guys to blind the good guys. Which is why no one touches my laser except me. I love it though. 

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1 hour ago, ollypenrice said:

1 Mw is plenty

Should this be 1mW? A 1MW laser would have 10 to the power 9 times the power. Ideal for removing foreground obstructions, when wishing to view low-altitude objects 😎.

Geoff

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2 hours ago, Geoff Lister said:

Should this be 1mW? A 1MW laser would have 10 to the power 9 times the power. Ideal for removing foreground obstructions, when wishing to view low-altitude objects 😎.

Geoff

This nicety was lost on me but, yes, I'm happy to spare any intervening life forms!

Olly

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I think it is reasonable to say contributors to this forum will be using a laser pointer in a sensible manner. Not deliberately pointing at an aircraft or a person.
We are hopefully trying to buy lasers that are suitable for the task. That is limited power, not the biggest baddest brightest light sabre around.w
In reality what are the risks to others if a laser is used sensibly?

Considering aircraft first. You intend to turn on your laser for a few seconds, pointing to the sky. You are going to be looking at the sky before doing this.
Any aircraft in the vicinity will be displaying navigation lights, so are conspicuous. You therefore delay turning on the laser until the aircraft is well away.

If the worst happens and you point at an aircraft, you have a fixed heading and the aircraft is moving so any illumination is fleeting.
If - another big if - a crew member happens to be looking towards you, they will only have momentary illumination as they continue their track.
In general at night flight crew use instruments more than the view outside. Final approach on landing and police observation is different.
You will be well aware of either of these situations apply.

The probability of an aircraft heading directly towards you, or tracking on the same path as your searching is all but zero.

The lasers we buy are not that good in terms of beam spread. This means energy per unit area received at a distance is going to be small.
I have tried laser pointers on solid fixed targets like walls. At a couple of hundred metres, you can get a metre or more beam spread.
Some are better than others. The point is, at distance the energy into an eye is going to be small.
At hundreds of metres (aircraft distance) there is not enough to do harm before the unintended recipient can blink or turn turn away.

Exposure by those around you is something different. The full energy is available to go into an eye.
The biggest dangers (to me) are a scope pointing at head height, rather than the sky, and a nearby reflection.
If the scope slips on the mount, the pointer can go anywhere. We will always try to catch a falling scope/tripod.
By having a push button, rather than maintained switch, the danger is removed. Unless you happen to push the laser button while catching the scope.
A properly sited button, or a gurd ring reduce risk here.
By siting the scope sensibly, you don't have to worry about reflections - unless someone on outreach waves a mirror in front of your scope.

When we buy a laser from the likes of ebay, or amazon marketplace, we have no idea of the power output and performance.
A claimed 10mW might be 1mW or 100mW. We cannot measure it.
Think of it like like buying a battery with a 1.5V label, but not knowing if it produces 0.15V or equipment destroying 15V.
I don't use a laser in astronomy. But if I did, it would come from a specialist optical/laser supplier.
That ensures I have a product with the claimed power, rather than 10x and dangerous power.
Also a purchase record, part number, etc. showing a 'legal' laser to show to authorities if there is argument.

To get things into perspective. A brief web search says 200mW is enough to pop a balloon and melt black plastic.
I have a laser engraver with a claimed 1500mW (1.5W) power output. But no idea of actual power.
It runs at low power for focussing and setup, then switches to full power where it happily burns wood and melts plastic.
No I haven't tried it on my finger🔥

HTH, David.

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It is notable that views tend to differ depending on which side of the Atlantic the respondent is on.

Personally I feel no need or desire to use a laser pointer. My scopes are aimed by GoTo, which means that if I am using a red dot pointer at all I am not aiming at alignment stars with extreme altitude, and I also have a right angled finder. 

Starsense also avoids the desire to use a laser pointer.

Not trying to point the finger at anyone, but are some respondents (legally) using laser pointers that would be illegal under UK regulations?

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Probably worth reading this page:

https://www.gov.uk/government/news/tough-new-penalties-for-misuse-of-lasers

In the UK I would think it better not to have to defend oneself from an accusation of misuse. We all know that a laser can be handy and a legitimate use in astro but considerable caution needs to be applied. Each to their own choice, of course but a minority of idiots have resulted in official kick-backs and laws, unsurprisingly.

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14 hours ago, dobblob said:

One might well ask why anyone needs a finder, a Telrad or setting circles? A laser is just another tool that helps us navigate around the sky. 

Many of us are getting a little long in the tooth and don't enjoy the pain of trying to crank our necks to view a red dot or straight through finder or dealing with the field flip and narrow views of a right angled or RACI finder.

A laser pointer has definitely improved my star hopping experience. I gave up on my Telrad  and finder.

Of course I understand the dangers of LP's and those that use them stupidly or maliciously should be punished to the full extent of the law.

But let that not condemn all of us as pariahs.

We all own a knife or a hammer but we don't rampage through the neighborhood stabbing and bludgeoning people. We use them to eat or drive nails.......

I use my laser to aim my scope....

I don't understand why anyone would want any of the RDF/telrad kind of thing myself.  Why on earth would I want zero mag on a finder, but it is a to each their own kinda thing.  

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1 hour ago, Cosmic Geoff said:

It is notable that views tend to differ depending on which side of the Atlantic the respondent is on.

Personally I feel no need or desire to use a laser pointer. My scopes are aimed by GoTo, which means that if I am using a red dot pointer at all I am not aiming at alignment stars with extreme altitude, and I also have a right angled finder. 

Starsense also avoids the desire to use a laser pointer.

Not trying to point the finger at anyone, but are some respondents (legally) using laser pointers that would be illegal under UK regulations?

They are not illegal.  Improper use is illegal. 

Jim 

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26 minutes ago, Mike Q said:

I don't understand why anyone would want any of the RDF/telrad kind of thing myself.  Why on earth would I want zero mag on a finder, but it is a to each their own kinda thing.  

All sorts of reasons for using a Telrad.

-  You can put a Telrad circle (transparent overlay in Wil Tirion's atlas, virtual one to scale on software planetaria) and mentally note its position relative to a couple of nearby naked eye stars. You really only need two. It is then easy to replicate the Telrad's position on the sky relative to those stars and there's rarely any need to star hop. One can drop onto the target almost directly from the Telrad or directly from it when lucky. This is where the circle beats a dot because the circle gives a sense of scale. Certainly the way my visual perception works, and this does vary between people, there is no substitute for those circles.

- Initial alignment stars: you know without doubt that you're on the bright star in question and not accidentally centering on one nearby.

- It is nice to have this very direct link between the telescopic and the naked eye view. 'So where is this object, exactly?' is a question often asked by our beginner guests and the Telrad answers that for them precisely.

- My imaging rigs, like others no doubt, are complex in shape and bulky. (Two large refractors in parallel on a large GEM with CCDs and filterwheels in the back. There is literally no single position in which a finder is accessible at all positions in the sky. Because the Telrad has no parallax it can be viewed at a distance and sufficiently off-axis to be workable anywhere these rigs look. (my mounts don't have a home park position so I need a one-star alignment to start the session.)

- It will do many of the things a laser will do if you don't want to, or can't, use a laser.

For me the Telrad is one of those items which, once tried, you'll never want to be without. (A bit like heated handlebar grips on a motorcycle! 🤣)

Olly

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4 minutes ago, ollypenrice said:

All sorts of reasons for using a Telrad.

............

For me the Telrad is one of those items which, once tried, you'll never want to be without. (A bit like heated handlebar grips on a motorcycle! 🤣)

Olly

Totally agree, a Telrad is one of those rare pieces of astro equipment that simply work and do it very well.  Design classic really. 

Jim 

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2 minutes ago, saac said:

Totally agree, a Telrad is one of those rare pieces of astro equipment that simply work and do it very well.  Design classic really. 

Jim 

And long lived. One of mine has just croaked after about 25 years...

Olly

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8 minutes ago, ollypenrice said:

All sorts of reasons for using a Telrad.

-  You can put a Telrad circle (transparent overlay in Wil Tirion's atlas, virtual one to scale on software planetaria) and mentally note its position relative to a couple of nearby naked eye stars. You really only need two. It is then easy to replicate the Telrad's position on the sky relative to those stars and there's rarely any need to star hop. One can drop onto the target almost directly from the Telrad or directly from it when lucky. This is where the circle beats a dot because the circle gives a sense of scale. Certainly the way my visual perception works, and this does vary between people, there is no substitute for those circles.

- Initial alignment stars: you know without doubt that you're on the bright star in question and not accidentally centering on one nearby.

- It is nice to have this very direct link between the telescopic and the naked eye view. 'So where is this object, exactly?' is a question often asked by our beginner guests and the Telrad answers that for them precisely.

- My imaging rigs, like others no doubt, are complex in shape and bulky. (Two large refractors in parallel on a large GEM with CCDs and filterwheels in the back. There is literally no single position in which a finder is accessible at all positions in the sky. Because the Telrad has no parallax it can be viewed at a distance and sufficiently off-axis to be workable anywhere these rigs look. (my mounts don't have a home park position so I need a one-star alignment to start the session.)

- It will do many of the things a laser will do if you don't want to, or can't, use a laser.

For me the Telrad is one of those items which, once tried, you'll never want to be without. (A bit like heated handlebar grips on a motorcycle! 🤣)

Olly

I got to try one once.  Never again.  It's a to each his own thing

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Posted (edited)
14 minutes ago, ollypenrice said:

And long lived. One of mine has just croaked after about 25 years...

Olly

Wow , that was an investment. Wait, it wasn't like Trigger's Broom Olly;  how many times did you replace the glass flat, bulls eye reticule, led and plastic body? :) 

Joking aside they are built well, I use one on the school's 16 inch Dob, and it is simplicity itself. However I do  wish it had a non latching switch though to prevent the led being left on accidentally.  I suppose I could retrofit one. 

Jim 

Edited by saac
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Not only simple to use, robust and accurate but also lightweight. For those of us using startracker camera mounts which need careful balancing and weight is a factor, the good old RDF is perfect - especially as you can get a close-up through the camera live view anyway.

I must try a Telrad. I have been meaning to. It may cut down on the amount of test shots I need to take when trying to frame an object without visible reference stars.

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2 minutes ago, Astro Noodles said:

Not only simple to use, robust and accurate but also lightweight. For those of us using startracker camera mounts which need careful balancing and weight is a factor, the good old RDF is perfect - especially as you can get a close-up through the camera live view anyway.

I must try a Telrad. I have been meaning to. It may cut down on the amount of test shots I need to take when trying to frame an object without visible reference stars.

Noodles, regarding framing etc. I've been using the ASiAir recently and I must admit it is a joy to use in that respect; target acquisition, plate solving, centring and framing is now a really effortless task.  The biggest drawback is it that it ties you to the use of ZWO cameras, unless you are using DSLR.  All said and done though, another worthy piece of kit. 

Jim

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2 minutes ago, saac said:

Noodles, regarding framing etc. I've been using the ASiAir recently and I must admit it is a joy to use in that respect; target acquisition, plate solving, centring and framing is now a really effortless task.  The biggest drawback is it that it ties you to the use of ZWO cameras, unless you are using DSLR.  All said and done though, another worthy piece of kit. 

Jim

Thanks Jim

I have a Raspberry pi4, guide scope 120mm etc. I just haven't got round to using it yet. 😄

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Posted (edited)

Tried red spot, and tetrad, went for a goto instead.

Lasers only used for entertaining the killer Kats, or collimation.

1 hour ago, saac said:

Noodles, regarding framing etc. I've been using the ASiAir recently and I must admit it is a joy to use in that respect; target acquisition, plate solving, centring and framing is now a really effortless task.  The biggest drawback is it that it ties you to the use of ZWO cameras, unless you are using DSLR.  All said and done though, another worthy piece of kit. 

Jim

works for me as all my cameras are ZWO or DSLR.

One day I must try a splitter cable for the DSLR shutter and run 2 side by side

Edited by iapa
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5 minutes ago, Louis D said:

Looks like stupid laser pointer use isn't limited to this side of the pond:

 

sadly not and of course once it's shown on TV series or news, loads more want to give it a go for a laff. It's not so much blinding that's the risk for aircraft but the fact that it lights up the windscreen and cockpit, wiping night vision for those operating under VFR which isn't good news when on final approach, esp in a tight built up area with tall structures lining the way.

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It’s illegal to point a laser pen at a flying aircraft. Otherwise, you have to exercise reasonable care as with, for example, fireworks. Leaving aside their legality, does pointing a laser pen at a star achieve anything tangible in terms of targeting? As a demonstration aid (“this is Arcturus, while this is  Vega”), I can see the value. Why would a laser pointer be better than a red dot finder? It would need to be mounted and aligned to be at least as good as a telrad or a Rigel. Are laser pens even collimated?! 

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5 hours ago, woldsman said:

It’s illegal to point a laser pen at a flying aircraft. Otherwise, you have to exercise reasonable care as with, for example, fireworks. Leaving aside their legality, does pointing a laser pen at a star achieve anything tangible in terms of targeting? As a demonstration aid (“this is Arcturus, while this is  Vega”), I can see the value. Why would a laser pointer be better than a red dot finder? It would need to be mounted and aligned to be at least as good as a telrad or a Rigel. Are laser pens even collimated?! 

Yes, pending the model, they can be collimatable.  Most use I suspect is for pointing stars/targets to others (outreach) and not as a finder type device mounted on a telescope.  That said, once mounted and aligned (there are suitable brackets for this) they can be used for exactly that. 

Jim 

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Posted (edited)
7 hours ago, woldsman said:

It’s illegal to point a laser pen at a flying aircraft. Otherwise, you have to exercise reasonable care as with, for example, fireworks. Leaving aside their legality, does pointing a laser pen at a star achieve anything tangible in terms of targeting? As a demonstration aid (“this is Arcturus, while this is  Vega”), I can see the value. Why would a laser pointer be better than a red dot finder? It would need to be mounted and aligned to be at least as good as a telrad or a Rigel. Are laser pens even collimated?! 

Here is my set up.  Works perfectly.  After I set the finder to the eyepiece I set the laser to the finder.  When I want to find something I press the switch and move the very visible beam to my next target.  Once there the button is released, the laser shuts off and the target is in my finder and generally fairly well centered in the eyepeice.  Is it better then a telrad or RD?  Well that is a personal choice.  I used a telrad once and I definitely don't want one.  Maybe they work in an application different then mine, but for me....my set up is as close to perfect as I can ask for.  As for collimation.....it not like using a laser to adjust your mirrors.  So it really isn't an issue when using it just as a pointer 

IMG_20220607_194155507.jpg

IMG_20220607_194200079.jpg

Edited by Mike Q
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