Author Topic: Deciding between a laser collimator or a light filter  (Read 684 times)

blacosticna

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Deciding between a laser collimator or a light filter
« on: December 29, 2017, 06:00:38 AM »
Hi all,

 I am currently thinking of buying a telescope, that is the Skywatcher Heritage 130P, or as it is better known in the US, the AWB Onesky 130. I live in a highly light-polluted city (Bortle8-9) with some occasional opportunities to travel to less light-polluted places (Bortle 5-6). I am choosing between 2 different accessories now due to budget constraint, one being an OEM Laser Collimator for Newtonians, and another being the Optolong Moon and Skyglow Filter. Both are of roughly similar prices in the bundle that the retailer is providing, about US$40.
More specifically, I would like to ask 2 main questions:
1. How is the filter rated? Will it show a good result in filtering out unwanted light and improving contrast of planets and brighter DSOs? How does moon viewing rack up against a standard ND moon filter?
2. Will collimating the telescope be much more difficult and tedious without the laser collimator?
What do you guys think? Please do leave some experiences from using these accessories and if possible, specifically on the scope. Thank you all in advance and clear skies!

Regards,
Dennis

Skywatcher Heritage 130P:
https://www.firstlig...p-flextube.html
(This is the scope, but I am not buying from this retailer.)



Dave Jones

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Re: Deciding between a laser collimator or a light filter
« Reply #1 on: December 30, 2017, 07:25:55 AM »
Dennis:

First let me say, I think the SkyWatcher Heritage is a fine scope and should serve you well.

- Moon and Sky Glow filters: In general, these are not much help in combating light pollution. The filters that are effective are only effective on certain nebulae but on those nebulae, they are very effective.

- OEM laser collimator:  Lasers can be great tools for collimating a Newtonian. But there are a number of issues that complicate things. OEM lasers are generally not collimated themselves so the first step is collimating the laser. This is doable. But even with a collimated laser, adjusting the primary is problematic because if one just uses the return spot beam, it is of dubious accuracy. If one is going to use a laser for collimating a Newtonian, I consider it mandatory to use the Barlowed Laser technique. This only requires a Barlow lens and cutting out a paper target.

With a short, easily accessed telescope like the Heritage, using a collimation cap to align the primary is very easy, you can view through the eyepiece and adjust the collimation at the same time.

I would hold off on the accessories until you get your scope. If you want to buy something useful, a third eyepiece or a Barlow lens would be a good investment.

Jon

Ghassan Pham

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Re: Deciding between a laser collimator or a light filter
« Reply #2 on: December 30, 2017, 08:48:12 AM »
Quote
Dennis:

First let me say, I think the SkyWatcher Heritage is a fine scope and should serve you well.

- Moon and Sky Glow filters: In general, these are not much help in combating light pollution. The filters that are effective are only effective on certain nebulae but on those nebulae, they are very effective.

- OEM laser collimator:  Lasers can be great tools for collimating a Newtonian. But there are a number of issues that complicate things. OEM lasers are generally not collimated themselves so the first step is collimating the laser. This is doable. But even with a collimated laser, adjusting the primary is problematic because if one just uses the return spot beam, it is of dubious accuracy. If one is going to use a laser for collimating a Newtonian, I consider it mandatory to use the Barlowed Laser technique. This only requires a Barlow lens and cutting out a paper target.

With a short, easily accessed telescope like the Heritage, using a collimation cap to align the primary is very easy, you can view through the eyepiece and adjust the collimation at the same time.

I would hold off on the accessories until you get your scope. If you want to buy something useful, a third eyepiece or a Barlow lens would be a good investment.

Jon

Thank you so much for your reply, I genuinely appreciate it. I understand your point that the filter may not be effective overall, but can you provide some examples of the nebulae on which are the filter is "very effective"? Are there any galaxies with good effects too? Or are there any filters of a similar price range that are effective too?
I have not heard much about the collimation cap yet, I assume I will have to buy it separately as an accessory? Or is it possible to collimate without any accessory at all?

John Abreu

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Re: Deciding between a laser collimator or a light filter
« Reply #3 on: January 04, 2018, 07:58:02 AM »
It is better to buy and use chip Cheshire eyepiece instead the laser.
OptolongMoon and Skyglow can not help you against light pollution

SW Heritage? It looks like not so good a horse to buy her a saddle...

jumphindnore

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Re: Deciding between a laser collimator or a light filter
« Reply #4 on: January 09, 2018, 09:52:21 PM »
As it reads you do not yet have a scope I would suggest adding the filter/collimator money to he scope money and getting a 150P dobsonian.

It is an extra £70 but if using and transporting it is not a problem then it will be a better option.

The 130 reads nice but you will need a surface on which to place it - kneeling on the ground that low is not an option. So the relative ease of transport disappears as there is then the need for a table which has to be transported. Also the collimation adjustment looks a little questionable - single rod to the secondary. Being collapsable and f/5 I guess you would need to collimate it (or check it) at almost every use.

Better say I do not like those small newtonians. I always have the idea someone has sat down and thought up a way to make a small scope just to sell and the reality and practicallity of them is secondary. Probably a case where I suspect they deter as many from astronomy as they are supposed to attract to it.

Picking up on the other reply: Collimation cap is a insert into the focuser which has a small central hole in it. You adjust everything so they appear central. One of the "best" are the "Posh Plugs" sold on Astroboot. On all the ones I have under the Astro Engineering sticker there is a central well engineered 2mm hole through the thing, remove that and you have a "Posh collimation cap". Go find Astro Baby's site as she has mention of them.

Many are hand made from an old 35mm film cannister. The Astro Boot plugs are much better.

Galaxies are "white" so any filter does nothing for them other then to nake seeing them worse. Remember that no filter "adds" they all remove. It is a question of what they remove and how much. I see too much mention of a filter making something "brighter", they cannot - they may improve contrast but that is not brighter.

At 130mm the scope needs all the light it can, even the moon will not be excessively bright, but it will leave a residual image for 30 seconds. So do not look at moon, stand up and walk anywhere immediatly, you will just walk into things or stand on cats, dogs, little children. Been there, done that, got told off for being childish.

Have you literally just changed your signature? Sure I read Southampton in it somewhere, Probably me going mad.

Find a club if possible whereever you are, seeing equipment that people use is very useful. Generally not what you half expect.

trualolalun

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Re: Deciding between a laser collimator or a light filter
« Reply #5 on: January 10, 2018, 01:02:19 PM »
I use Moon and Skyglow filters. They help some with the Moon and Sodium Vapor street lights. I have one that's a Svbony filter from eBay for $8 an another one made by Ostara that cost $19. They don't eliminate all the light pollution, but they help some. I use the Moon and Skyglow filters when the moon is less than half full. When the Moon is more than half full, I use a 13% ND Moon filter. I also use the Moon and Skyglow filters when starhopping.

Nate Flores

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Re: Deciding between a laser collimator or a light filter
« Reply #6 on: January 11, 2018, 02:26:47 AM »
Quote
As it reads you do not yet have a scope I would suggest adding the filter/collimator money to he scope money and getting a 150P dobsonian.

It is an extra £70 but if using and transporting it is not a problem then it will be a better option.

The 130 reads nice but you will need a surface on which to place it - kneeling on the ground that low is not an option. So the relative ease of transport disappears as there is then the need for a table which has to be transported. Also the collimation adjustment looks a little questionable - single rod to the secondary. Being collapsable and f/5 I guess you would need to collimate it (or check it) at almost every use.

Better say I do not like those small newtonians. I always have the idea someone has sat down and thought up a way to make a small scope just to sell and the reality and practicallity of them is secondary. Probably a case where I suspect they deter as many from astronomy as they are supposed to attract to it.

Picking up on the other reply: Collimation cap is a insert into the focuser which has a small central hole in it. You adjust everything so they appear central. One of the "best" are the "Posh Plugs" sold on Astroboot. On all the ones I have under the Astro Engineering sticker there is a central well engineered 2mm hole through the thing, remove that and you have a "Posh collimation cap". Go find Astro Baby's site as she has mention of them.

Many are hand made from an old 35mm film cannister. The Astro Boot plugs are much better.

Galaxies are "white" so any filter does nothing for them other then to nake seeing them worse. Remember that no filter "adds" they all remove. It is a question of what they remove and how much. I see too much mention of a filter making something "brighter", they cannot - they may improve contrast but that is not brighter.

At 130mm the scope needs all the light it can, even the moon will not be excessively bright, but it will leave a residual image for 30 seconds. So do not look at moon, stand up and walk anywhere immediatly, you will just walk into things or stand on cats, dogs, little children. Been there, done that, got told off for being childish.

Have you literally just changed your signature? Sure I read Southampton in it somewhere, Probably me going mad.

Find a club if possible whereever you are, seeing equipment that people use is very useful. Generally not what you half expect.

I have not changed my signature, and I do not live in Southampton XD But that's OK
A great thanks for your reply anyway, but unfortunately as I intend to fly it overseas to relatively less light-polluted regions for hopefully better views, the 150p would be a little too bulky and heavy for me to carry up a plane, checked or not. Still, thanks for the recommendation, as I have indeed considered that scope before, only to be eliminated by the factor of portability. While the 130p is indeed a little smaller than I can hope for, it seems to give a decent balance of size, weight and power for a newbie like me
Also, I do appreciate your experiences on the collimation cap, filter and the little humourous episode on moon-viewing. I shall heed that well. Astronomy clubs are uncommon in my city as far as I know, and I have not heard of any events from the existing ones in the recent many months.

Jason Rivard

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Re: Deciding between a laser collimator or a light filter
« Reply #7 on: January 11, 2018, 07:28:27 AM »
Quote
I use Moon and Skyglow filters. They help some with the Moon and Sodium Vapor street lights. I have one that's a Svbony filter from eBay for $8 an another one made by Ostara that cost $19. They don't eliminate all the light pollution, but they help some. I use the Moon and Skyglow filters when the moon is less than half full. When the Moon is more than half full, I use a 13% ND Moon filter. I also use the Moon and Skyglow filters when starhopping.

Thank you for your experience. I would assume then that these filters you recommend do help to bring out brighter DSOs against a bright night sky? How do the two individual filters by Svbony and Ostara rank against the Optolong?

Richard Reed

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Re: Deciding between a laser collimator or a light filter
« Reply #8 on: January 12, 2018, 07:12:03 AM »
Sort out collimation first. What good would any filter do, if the view is cr^p?

Don't get thrown off course with all the options for first scope. Stick with your plan and learn from there.

thesaroha

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Re: Deciding between a laser collimator or a light filter
« Reply #9 on: January 13, 2018, 05:22:21 AM »
Quote
Quote

I use Moon and Skyglow filters. They help some with the Moon and Sodium Vapor street lights. I have one that's a Svbony filter from eBay for $8 an another one made by Ostara that cost $19. They don't eliminate all the light pollution, but they help some. I use the Moon and Skyglow filters when the moon is less than half full. When the Moon is more than half full, I use a 13% ND Moon filter. I also use the Moon and Skyglow filters when starhopping.

Thank you for your experience. I would assume then that these filters you recommend do help to bring out brighter DSOs against a bright night sky? How do the two individual filters by Svbony and Ostara rank against the Optolong?

There is a lot to know about filters for the deep sky but most observers find that broad band filters are of very limited usefulness, I have a Lumicon Deepsky filter but I just don't use it..

Jon

Matt Christopherson

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Re: Deciding between a laser collimator or a light filter
« Reply #10 on: January 13, 2018, 10:43:24 AM »
Use the collimation cap that comes with the scope, they're fine for the 130 f5. Filters won't help on seeing galaxies...nothing will but darker skies. I'd get a Planesphere and a red dot finder....the red dot finder would be the best investment for the scope. I prefer the Telrad finder, but that's a bit too big and heavy for that scope, but the red dot will work just as well and is very lightweight.  I'd give up an eyepiece before I gave up my Telrad or red dot, you'll find they're the best investment you could make. As the 130 is a widefield scope, you may not even need the regular finder much.

Tumbness Mendez

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Re: Deciding between a laser collimator or a light filter
« Reply #11 on: January 14, 2018, 03:59:32 AM »
Quote
Quote

I use Moon and Skyglow filters. They help some with the Moon and Sodium Vapor street lights. I have one that's a Svbony filter from eBay for $8 an another one made by Ostara that cost $19. They don't eliminate all the light pollution, but they help some. I use the Moon and Skyglow filters when the moon is less than half full. When the Moon is more than half full, I use a 13% ND Moon filter. I also use the Moon and Skyglow filters when starhopping.

Thank you for your experience. I would assume then that these filters you recommend do help to bring out brighter DSOs against a bright night sky? How do the two individual filters by Svbony and Ostara rank against the Optolong?
I never tried any Optolong filters, so I can't really say. The moon and skyglow filters help some with the Orion nebula, but don't really help with the Andromeda galaxy. These filters are very subtle. Some people like them, others don't. For me, they work ok enough to spend $8. I tried one Crystalview moon filter that really helped with moon contrast, but it made the Andromeda galaxy almost disappear. The Crystalview worked better for the moon than the generic moon and skyglow, but it didn't really help with anything else. From what I read, the Baader Neodymium are the best moon and skyglow filters, but I haven't tried one of those either.

Deandre Fulce

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Re: Deciding between a laser collimator or a light filter
« Reply #12 on: January 15, 2018, 01:12:54 PM »
The primary benefit of a laser collimator, as I understand it, is convenience when collimting large telescopes. When using a collimation cap or a cheshire you have to go back and forth to the screws on the end of the tube to make adjustments, then back to the eyepiece to see the effect.  With a laser you don't have to do that.

But on a small scope that benefit is really lost. If you had a 10" scope then the laser might offer some value.

I have an 8" Newtonian and I prefer the collimation cap. I have a laser but I find I get better results from the collimation cap.

Collimation tools you need and tools you don’t need
http://garyseronik.c...-what-you-dont/

How to Collimate an Orion Reflector Telescope using a collimation cap or a laser
https://www.youtube....h?v=YAVGcGEBmCE
As far as light pollution, as I understand it the filters can help with sodium and mercury vapor light pollution but don't do much for LED lighting.  My area has moved over to LEDs. I have two LP/Skyglow filters but I have not found them to be of much value.FILTERS
Useful filters for DSOs – Great intro/overview of filters and their use
Interesting application of the “blink” technique too.
http://www.prairieas...ep-sky-objects/
Cloudy Nights filter review and discussion
https://www.cloudyni...nebula +filters
Planets
The use of filters – by color
http://sas-sky.org/w...al-Filters1.pdf
Discussion about filters
http://www.cloudynig...-about-filters/
Planetary filters – By target
http://agenaastro.co...ary-filter.html
Using Planetary Filters – effect on the eye
http://www.alpo-astr...es/FILTERS1.HTM
Nebulae filters - DGM NBP filter review – This is from 2006 so may be out of date but how it was evaluaged may be useful.
http://www.cloudynig...la-filter-r1529For Nebula you are talking a different kind of filter. These might help you understand that better.

Scott Rogers

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Re: Deciding between a laser collimator or a light filter
« Reply #13 on: January 15, 2018, 11:51:27 PM »
Quote
Use the collimation cap that comes with the scope, they're fine for the 130 f5.  Filters won't help on seeing galaxies...nothing will but darker skies.  I'd get a Planesphere and a red dot finder....the red dot finder would be the best investment for the scope.  I prefer the Telrad finder, but that's a bit too big and heavy for that scope, but the red dot will work just as well and is very lightweight.   I'd give up an eyepiece before I gave up my Telrad or red dot, you'll find they're the best investment you could make.  As the 130 is a widefield scope, you may not even need the regular finder much.
The Heritage 130 does not come with a collimating cap. I know because that'sthe scope I chose for my first too. On the other hand one is not too hard to make, and the 130p does come with a red dot finder and with adjustable brightness to boot! It is a bit hard to use at first though due to its very narrow field of view so it's really easy to lose sight of the dot.
Based on my experience I would definitely recommend getting a better eyepiece or two with the 130p right from the start. I have a BST StarGuider 5mm coming this Friday, which I hear is a quite good piece for the price. Same thing is sold under many names. Others have recommended a 32mm plössl for it gives you the widest true field of view possible with a 1.25" eyepiece. I am thinking of getting one next.

Mark Rivera

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Re: Deciding between a laser collimator or a light filter
« Reply #14 on: January 16, 2018, 11:40:41 PM »
It's a great little scope. See my review on the AWB thread, about 2nd to last page. I used it last month as a travel scope in Hawaii.

As John said, save your money on filters, and forget the cheap collimating lasers. Get yourself a good collimating cap, or a Celestron combo collimating tool. BTW, I have only collimated mine once! When I set it up in Hawaii, I carefully checked collimation, and it was still spot on after traveling in a big duffle bag with clothes around it.

I use mine on a Vixen Porta mount, and at a dark site it is a very capable scope. I use a laser finder in lieu of any optical finder. Your money will be better spent on eyepieces and a barlow.