Laser Pointer vs Telrad

[maddog]

Hi

I am about to purchase a Dobsonian telescope.  As a relative newbie what are your suggestions on either a laser pointer vs telrad to help me find the stars, etc, that I am looking for?

 

Your thoughts and guidance is very welcome.

[wookie1965]

Just my two pennorth I have just bought a 10" dob it had a red dot finder I have now taken that off and put a Telrad on with a riser for better position. You would have to be careful with a laser so it doesn't interfere with aircraft. 

[bosun21]

I would also go for a telrad on a 2” riser plate especially if you are in the UK as lasers can bring their own legal problems.

[doublevodka]

Telrad or Rigel Quikfinder would get my vote too, thanks to idiots pointing lasers at planes over the years they are very much frowned upon, so better to be safe than sorry.

Many of the dob guys like to have a combo of red dot and RACI finder, although starsense explorer is becoming very popular now too.

https://www.firstlightoptics.com/celestron-starsense-explorer-series/cel_starsense_exp_8_dob.html

[maddog]

Good point.  I'm right under a military air-lane, don't want to go upsetting our friends from Fairford!

[maddog]

1 hour ago, doublevodka said:

Telrad or Rigel Quikfinder would get my vote too, thanks to idiots pointing lasers at planes over the years they are very much frowned upon, so better to be safe than sorry.

Many of the dob guys like to have a combo of red dot and RACI finder, although starsense explorer is becoming very popular now too.

https://www.firstlightoptics.com/celestron-starsense-explorer-series/cel_starsense_exp_8_dob.html

This is looking very interesting.  Will be using with kids and so need to keep them hooked!

[Guest]

Give me a laser everyday of the week and twice on Sundays thank you very much.  I run a laser and a RACI finderscope in a dual mount on my 10 inch and a laser and RACI mounted separately on my 16 inch.  Once you get everything aligned i press and hold the remote switch and follow the line to where i want to be.  Laser close, RACI closer and when i do everything right ..... the object will be in the eyepiece.  You couldnt give me a Telrad or Rigel. 

Edited March 24, 2023 by Mike Q

[Louis D]

Just look and listen for aircraft when using lasers.  The ones getting arrested are lasing police helicopters or landing aircraft from the end of the runway.

I've switched over from Telrad/QuikFinder (I have both) to laser sight (check on ebay) as my neck and back have gotten stiffer and more painful to contort.  I can be on target with a laser sight in under 5 seconds if bright stars or planets are nearby.

From there, I generally rely on a wide field 2" eyepiece to center the object.  I have a RACI, but don't find myself using it much.

For times when the sky is washed out, I'll use SkEye on my mounted smartphone to get to scope within a few degrees of a target.

This image shows my RACI, GLF, and QF setup.

 

While this image shows my RACI, SkEye, QF setup.

Edited March 24, 2023 by Louis D

[Mr Spock]

I have a Baader RDF on my frac and a Telrad on the Dob. I do prefer the Telrad as it's rings are very useful. It's too big for the frac though. A negative is the Telrad is prone to dewing.

 

[John]

On my 12 inch dobsonian I used a Rigel Quikfinder alongside a 9x50 RACI optical finder. Coupled with wide field eyepieces this approach has provided a decade of satisfying observing with some challenging targets located close to the observing limit for the aperture where I observe.

On my refractors I use RACI optical finders for the majority of the time but occasionally I use an illuminated reticule finder.  

Top end of my 12 inch dob:

 

[wookie1965]

18 minutes ago, Mr Spock said:

I have a Baader RDF on my frac and a Telrad on the Dob. I do prefer the Telrad as it's rings are very useful. It's too big for the frac though. A negative is the Telrad is prone to dewing.

 

Make a dew shield dead easy get a couple of files from poundland take the black plastic off then cut to shape out. 

Strong double sided tape and bobs your uncle. 

[Neil H]

Hi I have a telrad on my newt but you will need a riser on a dob , but on my mak I have baader super sky surfer not cheap but it's really nice well built and I can remove it and refit it and it keeps its set up spot on 

https://www.firstlightoptics.com/finders/baader-40mm-super-sky-surfer-v-night-day.html

[Guest]

48 minutes ago, wookie1965 said:

Make a dew shield dead easy get a couple of files from poundland take the black plastic off then cut to shape out. 

Strong double sided tape and bobs your uncle. 

I know Bob.... You dont want him as your Uncle LOL 

[doublevodka]

6 hours ago, maddog said:

This is looking very interesting.  Will be using with kids and so need to keep them hooked!

You don't have to buy the celestron one by the way, there are plenty of people buying cheaper StarSense scopes and then diying them onto another scope like dobs, have a search of StarSense on the forum and you'll find some info. For me it's certainly one of the more interesting developments in astronomy recently 👍 some dob purists prefer all manual and that's fine too, each to their own, but for me with limited observing time any help to get on target is a winner!

[bosun21]

I use the Celestron  Starsense unit i removed from their cheapest refractor the LT70. This alongside a RACI works flawlessly for me. I first used it on an 8” dobsonian but have now swapped it over onto my 12”. I slew to the target with the Starsense then centre it in the RACI before viewing it in the eyepiece.

[RT65CB-SWL]

Hi @Louis D

Apologies from side-tracking this topic, but how do you get SkEye to track/view the target when it is in a horizontal plane? (as shown in your second image). I can only get it to show the horizon when it is in the vertical plane. I would like to do the same with an 'old' Google Pixel 3a that I have.

Edited March 24, 2023 by Philip R

[Louis D]

Read up on SkEye DSC star alignment.  The key is to mount the phone to the scope and then use one of two alignment options: 1) select an alignment object in Indirect mode and slew to it and confirm or 2) point to a well known object and then drag the screen to the object and confirm it when centered.  I generally use the second method.

[Louis D]

I discovered another plus for the laser sight last night.  I had both my 6" Newt and 6" frac on either side of my alt-az mount.  The two sides aren't quite perfectly aligned.  So, I put the laser on the Newt (and aligned it) and the RACI on the frac.  I would find a dim object scanning the sky with the Newt (shorter focal length makes it easier) and observe it for a bit.  Then, to center it in the frac for comparison purposes, I would light up the laser while looking through the RACI which was aligned with the frac.  I would note where it was pointing on the sky in the RACI FOV, quench the laser, and move the RACI crosshairs to where the laser had just been pointing.  BOOM!  The frac is centered on the same object in seconds.  It's much quicker, easier, and more accurate than jumping between two RDFs on two scopes to do the same.  Yes, I need to work on getting the two sides of the mount aligned better, but this was a great workaround.

[Spile]

A RACI and Telrad work for me.

[bomberbaz]

Plus 1 more here for a laser. Much more fun to use and as others have pointed out, I too find it much easier to use than a telrad or similar.  It is also used in conjunction with a RACI.

[bosun21]

After reading this thread I’m thinking about giving a laser pointer a try. I have an empty finder shoe fitting on my triple unit. I know that there’s a lot of Micky mouse pointers out there with wildly exaggerated power and rating claims. Does anyone have a recommendation for one, being from the UK? Thanks.

[AstroKeith]

9 hours ago, bosun21 said:

After reading this thread I’m thinking about giving a laser pointer a try. I have an empty finder shoe fitting on my triple unit. I know that there’s a lot of Micky mouse pointers out there with wildly exaggerated power and rating claims. Does anyone have a recommendation for one, being from the UK? Thanks.

You will note that those above suggesting lasers are in the USA. Lasers in the UK are more problematic.

a) Our air traffic density is higher. Also so is our population density, so more likely for someone to 'report' you.

b) The 'new' legal max power in the UK is 1mW. Anything beyond that (ie the 5mW often sold) require very careful use (formal training and sign offs, etc) to not fall foul of the Health and Safety legislation. 

c) No UK event will allow you to use one.

[Zermelo]

This comes up fairly regularly. Apologies @bosun21, you may have already done your research on the following, but for others looking at this, three more points:

(a) Lab tests have shown that significant numbers of imported lasers exceed the 1mW UK limit, even where  the specs says they don't. Some are massively over.

(b) Be especially careful if ordering the 532nm variety, as these use frequency doublers on IR lasers to get to the green output. The potential problem is that the efficiency of the conversion falls in cold temperatures, leaving substantial amounts of IR output. There is supposed to be a cut filter to remove it, but some don't work very well (or are missing). Your eyes can be damaged, and the blink reflex won't cut in as it's mostly IR.
520nm lasers are inherently safer as they don't use this mechanism, but most of the cheaper imports are not of this type.

(c) In the UK at least, the legislation now makes shining a laser at a plane (or other vehicles) a strict liability offence, i.e. they don't need to prove that you did it deliberately to ensure a conviction.

I do understand the appeal of using lasers on scopes, and I have several times thought about trying to find a "safe" one, but always decided against it.

 

[bosun21]

9 minutes ago, Zermelo said:

This comes up fairly regularly. Apologies @bosun21, you may have already done your research on the following, but for others looking at this, three more points:

(a) Lab tests have shown that significant numbers of imported lasers exceed the 1mW UK limit, even where  the specs says they don't. Some are massively over.

(b) Be especially careful if ordering the 532nm variety, as these use frequency doublers on IR lasers to get to the green output. The potential problem is that the efficiency of the conversion falls in cold temperatures, leaving substantial amounts of IR output. There is supposed to be a cut filter to remove it, but some don't work very well (or are missing). Your eyes can be damaged, and the blink reflex won't cut in as it's mostly IR.
520nm lasers are inherently safer as they don't use this mechanism, but most of the cheaper imports are not of this type.

(c) In the UK at least, the legislation now makes shining a laser at a plane (or other vehicles) a strict liability offence, i.e. they don't need to prove that you did it deliberately to ensure a conviction.

I do understand the appeal of using lasers on scopes, and I have several times thought about trying to find a "safe" one, but always decided against it.

 

Thanks for the further information and I have totally abandoned the notion of trying a laser. I was initially just curious to see what the fuss was about. Apart from all the technical pitfalls and legal issues in the UK, I reckon they are best avoided.

[Guest]

46 minutes ago, bosun21 said:

Thanks for the further information and I have totally abandoned the notion of trying a laser. I was initially just curious to see what the fuss was about. Apart from all the technical pitfalls and legal issues in the UK, I reckon they are best avoided.

Dont do it... Just dont.  No more sore necks, just look up and follow the beam is just too easy lol.  I have lasers on both my dobs, no way o would be without one now.