Green laser

[Rob72 (Robert)]

Recently I've found myself using a green laser more than my finderscope, albeit I'm strictly visual & practice star hoping rather than computer guidance.
I was wondering what people's thoughts are if this green light effects night vision.....
Rob

[RB (Andrew)]

Our eyes are more sensitive to the green 520/532nm wavelengths than other laser wavelengths, like 445nm blue and 638nm red at the same power level.
So green 532nm is ideal for visibility but is also detrimental to night vision if the power is too high.

Legally and ideally you should be using a 5mW laser for astro and only for short periods of time so it won't affect your night vision to any large extent.
Using a blue or red laser at their legal levels of 5mW would not be as visible so green 532nm at 5mW is ideal for astro use as a pointer.

Always be aware not to shine at aircraft and DO NOT look directly at the laser, even at 5mW because eye damage is instant even at low levels.

Also be aware that the green 532nm lasers also emit high IR which is invisible but very dangerous.
Better quality laser pointers have an IR filter installed to stop harmful IR emission but the cheaper Chinese eBay lasers don't and they are very dangerous to your eyesight.
Green 520nm lasers do not emit IR so they are safer in this respect but are harder to find and more expensive.

RB

[Wavytone]

Yes it will. There's another problem too - when aligned properly with your telescope, if the laser is on while you look through the scope you'll see the backscatter of the beam as green finger sticking into the field of view, which is more than a tad annoying if you're looking for something faint. The result is you need to switch the darned thing off while you use the scope.

While lasers are great for pointing things out to a crowd, they're not great as finders on a scope - IMHO a red-dot finder or Telrad are better, especially if the dot blinks off and on, you can see much fainter background stars etc in the vicinity of the dot. And you can leave them switched on too while you use the scope. Even the old-style 50 X 8 finder scope is better.

[RB (Andrew)]

.... but they do look cool on a scope.

[Rob72 (Robert)]

Thanks for your input everyone, I do only use the green laser for short bursts at any given time. I'm still learning to correlate what my charts show & what my naked eyes & scope see. For me I find the laser helps put the scope where I want it & then I zero in with the finder. I find using the finder alone a bit confusing as it shows so many more stars than a chart or star disk. I'm putting of a computerised mount until I feel sufficiently capable of navigating the old school way.

[barx1963 (Malcolm)]

I used a laser for quite a time. I had one that the switch only worked while I was pressing it so easy to use in short bursts. I now use a red dot finder which is just as good, but does involve a little neck craning, but I don't have to worry about legal issues or using at star parties.

I found a 10mw laser was fine, didn't overwhelm the night vision. One major downside is that they do not like the cold so have to be kept warm in winter or any cold nights!

Star hopping can be frustrating for the reasons you state. I found it much easier once I obtained a very high quality atlas ( Uranometria 2000) as it shows many more stars so the finder view was closer to the chart.

Malcolm

[lynkim1]

Never ever absentmindedly use a green laser pointer to highlight the location of an aircraft when your fellow observer asks "where?" ...especially when you live under the flight path of the RAAF base in your home town!

[Renato1 (Renato)]

Originally Posted by Rob72

For me I find the laser helps put the scope where I want it & then I zero in with the finder. I find using the finder alone a bit confusing as it shows so many more stars than a chart or star disk. I'm putting of a computerised mount until I feel sufficiently capable of navigating the old school way.

I've only ever done it the old school way. Good 6X30 finders are much easier to use for finding correlation between charts and what you see in the image, though with 8X50s I find a red dot finder or Telrad makes things a lot easier (since they basically do the same thing as your laser does).

Without using a red dot finder or laser, the tricky part is pointing the finder to the correct bright star in the sky from which to start your hopping. The trick is to keep both eyes open while doing so. If you close one eye, it is much harder to get that star in the field of the finder.
Regards,
Renato

[GrampianStars (Rob)]

Originally Posted by Wavytone

.....IMHO a red-dot finder or Telrad are better, especially if the dot blinks off and on, you can see much fainter background stars etc in the vicinity of the dot. ......

Hi
Which model red-dot finders blink
I could use one on very faint objects

[AndrewJ]

Gday Rob

Rigel quikfinders blink
You get two circles with ful control over intensity and blink rate.
Much smaller than a Telrad.

Andrew

[GrampianStars (Rob)]

Thanks Andrew

I will get a late Santa one for my beast
currently using a Orion EZ Finder II red dot finder
and it doesn't dim enough & it's a pain to manually blink it

[Renato1 (Renato)]

I've got the blinking option on one of my Telrads. I rarely use it, though the option would be handy if one only has the blinking finder rather than using it in conjunction with a regular finder.
Regards,
Renato