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Hydrogen Alpha Filter

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#1 Quartz

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Posted 06 September 2021 - 09:39 AM

So, I'm taking the plunge into night vision and I'm on the waiting list for the night vision setup through TeleVue. Started looking at the Hydrogen Alpha filters and just wondering if anyone can offer me any advice on which filer(s) to get?

 

I live in a major city , so Bortles 8 skies 

I have a sky-watcher 10 inch dob so it's f/4.7

 

I've looked at the 2" Astronomik 6nm and saw that's almost $500 but I've noticed the Baader 7nm and Optlong 7nm are closer to $300. Is there really a discernable difference between Astronomik and the Baader / Optlong? I'd like to save a little money where possible and put some savings towards another filter but if Astronomik is that amazing, I'll probably just go with that. 

 

If anyone has any other advice, even non filter related, I'm all ears. 

 



#2 Mazerski

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Posted 06 September 2021 - 09:46 AM

Ha filter: I live in B7 sky and the Astronomik 6nm is what I use the most

 

You will need IR filter to darken background such that you have good contrast when looking at Globulars, open clusters and galaxies. The Baader 685nm works well. 
 

Can you use 1.25” Filters? 



#3 Quartz

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Posted 06 September 2021 - 10:07 AM

Ha filter: I live in B7 sky and the Astronomik 6nm is what I use the most

 

You will need IR filter to darken background such that you have good contrast when looking at Globulars, open clusters and galaxies. The Baader 685nm works well. 
 

Can you use 1.25” Filter

 

OK that's good to know as well, thanks!

 

Actually , I'm not sure if I can or not. It's the PVS-14 so I guess if I was using 1x I could use 1.25 but with the Televue 55, I'd need a 2". Not sure if I could use a 1.25 in conjunction with the 55 Plossl as well?



#4 Mazerski

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Posted 06 September 2021 - 10:43 AM

I don’t have a 14 nor setup for Afocal... either way, you will need / want the IR filter for without it you get no contrast between DSO and background and the view borders on terrible. 
 

I have no knowledge of other filter brands for Ha but the NV experts created this post and you should look as Optlong is mentioned

 

https://www.cloudyni...s#entry11173899

 

 

 

 

 



#5 stnagy

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Posted 06 September 2021 - 12:58 PM

OK that's good to know as well, thanks!

 

Actually , I'm not sure if I can or not. It's the PVS-14 so I guess if I was using 1x I could use 1.25 but with the Televue 55, I'd need a 2". Not sure if I could use a 1.25 in conjunction with the 55 Plossl as well?

I use the TV 55 and I can't think of how you'd use 1.25" filters without some kind of custom modification to put it between the eyepiece and the NVD. 



#6 GOLGO13

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Posted 06 September 2021 - 01:00 PM

So, I'm taking the plunge into night vision and I'm on the waiting list for the night vision setup through TeleVue. Started looking at the Hydrogen Alpha filters and just wondering if anyone can offer me any advice on which filer(s) to get?

 

I live in a major city , so Bortles 8 skies 

I have a sky-watcher 10 inch dob so it's f/4.7

 

I've looked at the 2" Astronomik 6nm and saw that's almost $500 but I've noticed the Baader 7nm and Optlong 7nm are closer to $300. Is there really a discernable difference between Astronomik and the Baader / Optlong? I'd like to save a little money where possible and put some savings towards another filter but if Astronomik is that amazing, I'll probably just go with that. 

 

If anyone has any other advice, even non filter related, I'm all ears. 

The Baader 7nm and astronomik 6nm will be very close in capability. Either one is good. Check the used market also for these.

 

One of those would cover your nebulas. In your situation I'd also suggest a 685 long pass filter. The Baader does well.

 

Good choice on the TeleVue. The 55mm plossl and the 67mm adapter would be worth getting. It's a really tall stack, but it works well with my scope (an Orion 10 inch F4.7). That scope is my best NV scope, so it will do very well. You'd probably want another eyepiece that is less reduced also.

 

Should be a lot of fun.



#7 GOLGO13

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Posted 06 September 2021 - 01:01 PM

Yes, get the 2 inch filters and the adapter for using the 2 inch filter at 1x.

 

In an afocal situation I think 2inch is the way to go.



#8 GOLGO13

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Posted 06 September 2021 - 01:23 PM

Another thing I'd advise is stick with the single HA filter whatever you end up getting. I've found they are all pretty similar in capability. I think 6-7nm is a good in-between and works fine for most situations.

 

And in your skies the 685 should be fine. If you go to very dark skies, unfiltered would be fine and you wouldn't probably need the 685.

 

Do you have any other telescopes?



#9 Quartz

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Posted 06 September 2021 - 04:57 PM

Another thing I'd advise is stick with the single HA filter whatever you end up getting. I've found they are all pretty similar in capability. I think 6-7nm is a good in-between and works fine for most situations.

 

And in your skies the 685 should be fine. If you go to very dark skies, unfiltered would be fine and you wouldn't probably need the 685.

 

Do you have any other telescopes?

OK , great, thanks! 

 

I just have a 6" reflector besides my 10 inch.



#10 GOLGO13

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Posted 06 September 2021 - 07:43 PM

Ok...well, the 10 inch is very good. And with the 67mm setup it can get reduced fairly far to get a wider field. Is your 6 inch reflector F5? if so that would be pretty good too.

 

1x is nice for some things. Checking out the milky way, finding objects, watching satellites, seeing random shooting stars, seeing some of the larger nebulas, etc.

 

I think it maybe worth considering sometime in the distant figure a smaller scope for wide fields like a 100mm F5 refractor (if your reflector is a longer focal ratio). With heavy filtering achromats work fine.  

 

I don't do a ton of a-focal, I just got the 67mm setup and I do recommend it (just be aware it's a pretty crazy stack coming off the focuser). I'm not sure what eyepieces would be best outside of the 67mm setup. I'd imagine something like the 27mm Panoptic would be good. That would be a good neutral eyepiece and wouldn't have much or any reduction, but give you some more magnification on some objects. My device does both prime focus and A-focal. Don't worry about this though, a-focal is fine and you just need a few eyepieces to make that work. TeleVue has a listing of eyepieces to use with it.

 

If you have a Paracorr it does work with the 67mm setup, but I don't think it's necessary really. Especially for nebula work. 

 

NV provides dark sky like visual observing to a light polluted sky. Meaning, dark sky with glass feel to it. Don't judge your observations on one or two nights. Sometimes the conditions may not favor NV as well as others. At least that's how it's been for me. Could be different in Florida.



#11 Dale Eason

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Posted 06 September 2021 - 07:50 PM

If you live in Bortle 8 skies like me then the HA 3.nm from Antila  will show better than the 7nm.   However I used the 7nm for a year before getting the 3.  A few nights ago I compared the two once more and still prefered the 3nm Antila to the Baader 7nm.


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#12 GeezerGazer

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Posted 07 September 2021 - 12:46 AM

Hi Quartz,

A Google search for 685nm Long Pass filters reveals Baader is ~$144 and Optolong ~$120 from our US vendors.  I've used both and both are satisfactory; I seldom see distinctions between this sort of filter when used visually.  If you can wait for it to be delivered, you should try Laida Optics in China, found on Ali Express... a brand new 2" Optolong 685nm can be had for $40.  Delivery takes about 3 weeks, but they keep you posted on every step of delivery. 

https://www.aliexpre....64085218F6Avqc

 

The difference between a 6-7nm or a 7-8nm H-a filter is very subtle.  Even two nanometers of difference are not real obvious on many H-a subjects.  The difference between 12 & 6nm or 6 & 3nm is quite obvious.  You have been given good advice to start with a 6-7nm filter.  Most of the phone images in my gallery were taken using a 7nm Optolong filter.  The filter I used is listed under each photo if you click on the photo to open it.  Photography is a lot different than visual use, so keep that in mind... YMMV.   https://www.cloudyni...59-geezergazer/

 

Using afocal, you should almost certainly plan on 2" filters.  2" filters can be adapted to use on the 1x lens too.  The TV 55/67 lens is most valuable to afocal users, so you have made a good choice with it.  In my experience, results with it were best in my optical systems compared to any other useable option... I tried many.  

 

I hope your NVD arrives soon and you have Clear Skies.



#13 Quartz

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Posted 07 September 2021 - 07:10 AM

Hi Quartz,

A Google search for 685nm Long Pass filters reveals Baader is ~$144 and Optolong ~$120 from our US vendors.  I've used both and both are satisfactory; I seldom see distinctions between this sort of filter when used visually.  If you can wait for it to be delivered, you should try Laida Optics in China, found on Ali Express... a brand new 2" Optolong 685nm can be had for $40.  Delivery takes about 3 weeks, but they keep you posted on every step of delivery. 

https://www.aliexpre....64085218F6Avqc

 

The difference between a 6-7nm or a 7-8nm H-a filter is very subtle.  Even two nanometers of difference are not real obvious on many H-a subjects.  The difference between 12 & 6nm or 6 & 3nm is quite obvious.  You have been given good advice to start with a 6-7nm filter.  Most of the phone images in my gallery were taken using a 7nm Optolong filter.  The filter I used is listed under each photo if you click on the photo to open it.  Photography is a lot different than visual use, so keep that in mind... YMMV.   https://www.cloudyni...59-geezergazer/

 

Using afocal, you should almost certainly plan on 2" filters.  2" filters can be adapted to use on the 1x lens too.  The TV 55/67 lens is most valuable to afocal users, so you have made a good choice with it.  In my experience, results with it were best in my optical systems compared to any other useable option... I tried many.  

 

I hope your NVD arrives soon and you have Clear Skies.

 

Hmmm, definitely worth a try. How come it's so much cheaper through Ali Express? noticed their Optlong 7nm H-a is half the price as well. Definitely worth it if they're both the real deal, however I tend to be skeptical. Have you bought from them before?


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#14 GOLGO13

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Posted 07 September 2021 - 08:03 AM

Hmmm, definitely worth a try. How come it's so much cheaper through Ali Express? noticed their Optlong 7nm H-a is half the price as well. Definitely worth it if they're both the real deal, however I tend to be skeptical. Have you bought from them before?

One potential issue with buying international right now is the shipping backlog. Ships stuck outside ports. I'm not sure if these items would come via ships or if they'd be airlifted. But I could see that being a potential issue. I've bought something from Aliexpress in the past and it came fine. It did take a bit of time (before the pandemic). There could be some bad experiences, but I've heard mostly good things. I just worry about the shipping issues causing more delays.

 

Why they are cheaper I don't know. Probably just cutting out the middle man and not marked up.

 

I think for me I'd try the classifieds instead. I don't see any currently in the CN classifieds or Astromart. 

 

It is interesting that Dale saw good improvement with the 3nm Antila: https://agenaastro.c...-2-mounted.html

 

I have a 3.5nm Antila in the 1.25 inch format. It did seem to be a hair more detailed compared to my 6nm. But not super dramatic to my eye. But going from 12nm to 3.5nm is where I see the most difference. The nebulas are just more defined with the 3.5nm. That doesn't mean the 12nm isn't good, just not as defined as the more narrow filter. 

 

It is possible that in heavier light pollution that could be a consideration to what you'd want to use. My level is Bortle 6 so not quite as bad. 

 

The Antila filter I have seems to be of high quality. My opinion is you only really need one filter from 8nm to 3nm. I have seen a few times having a 12nm is helpful. Maybe in situations where less light is needed to be cut out. But if I remember this was not very often.

 

So you may want to consider that Antila 3nm filter for bortle 8 situations.



#15 Quartz

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Posted 07 September 2021 - 08:45 AM

One potential issue with buying international right now is the shipping backlog. Ships stuck outside ports. I'm not sure if these items would come via ships or if they'd be airlifted. But I could see that being a potential issue. I've bought something from Aliexpress in the past and it came fine. It did take a bit of time (before the pandemic). There could be some bad experiences, but I've heard mostly good things. I just worry about the shipping issues causing more delays.

 

Why they are cheaper I don't know. Probably just cutting out the middle man and not marked up.

 

I think for me I'd try the classifieds instead. I don't see any currently in the CN classifieds or Astromart. 

 

It is interesting that Dale saw good improvement with the 3nm Antila: https://agenaastro.c...-2-mounted.html

 

I have a 3.5nm Antila in the 1.25 inch format. It did seem to be a hair more detailed compared to my 6nm. But not super dramatic to my eye. But going from 12nm to 3.5nm is where I see the most difference. The nebulas are just more defined with the 3.5nm. That doesn't mean the 12nm isn't good, just not as defined as the more narrow filter. 

 

It is possible that in heavier light pollution that could be a consideration to what you'd want to use. My level is Bortle 6 so not quite as bad. 

 

The Antila filter I have seems to be of high quality. My opinion is you only really need one filter from 8nm to 3nm. I have seen a few times having a 12nm is helpful. Maybe in situations where less light is needed to be cut out. But if I remember this was not very often.

 

So you may want to consider that Antila 3nm filter for bortle 8 situations.

Gotcha, at that makes sense about the delays but at the same time, the NV stuff I got on the waitlist for is 4 to 6 months out so if I have to wait even 2 months for these filters, that's fine. I'm not really worried about the shipping, just wanted to make sure the product is as described and is the real thing. I think I'd like to start off with the 7 nm right now and then see where things are and decide if I need to go lower like the 3nm. Good information though, thanks!



#16 GOLGO13

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Posted 07 September 2021 - 09:08 AM

Gotcha, at that makes sense about the delays but at the same time, the NV stuff I got on the waitlist for is 4 to 6 months out so if I have to wait even 2 months for these filters, that's fine. I'm not really worried about the shipping, just wanted to make sure the product is as described and is the real thing. I think I'd like to start off with the 7 nm right now and then see where things are and decide if I need to go lower like the 3nm. Good information though, thanks!



I think that makes sense. I can't say for sure on the Ali express stuff. May be worth doing more research. I'm personally more comfortable buying from a US company, but there is no doubt some serious money can be saved. And it's probably not a huge risk since the cost is low.

#17 Dale Eason

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Posted 07 September 2021 - 10:41 PM

Correction.  I have an Antila 3.5 nm  HA not 3 nm.   I remembered wrong. Sorry.


Edited by Dale Eason, 08 September 2021 - 01:14 AM.


#18 GOLGO13

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Posted 07 September 2021 - 11:10 PM

Correction.  I have an Antila 3.5mm  HA not 3 mm.   I remembered wrong. Sorry.

I have the 3.5nm in 1.25 inch format...it's a good filter.


Edited by GOLGO13, 07 September 2021 - 11:10 PM.


#19 bobhen

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Posted 08 September 2021 - 07:51 AM

I live in Bortle 8-9 and use a 6nm Ha filter. I had the 7 and I thought the 6 was “a tad better” and was worth it. I also use a 685 Pass filter for non-nebula objects. They are the only filters I use.

 

If you don’t have one, down the road you might also consider a small 80-102mm F5 achromatic refractor or 6” F4 Newtonian for very wide field, low power observing. The refractors are inexpensive and work very well with Night Vision.

 

You’ll soon discover the wonders of low power, wide field, deep sky observing, which with Night Vision is spectacular.

 

Bob



#20 GOLGO13

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Posted 08 September 2021 - 08:05 AM

I live in Bortle 8-9 and use a 6nm Ha filter. I had the 7 and I thought the 6 was “a tad better” and was worth it. I also use a 685 Pass filter for non-nebula objects. They are the only filters I use.

If you don’t have one, down the road you might also consider a small 80-102mm F5 achromatic refractor or 6” F4 Newtonian for very wide field, low power observing. The refractors are inexpensive and work very well with Night Vision.

You’ll soon discover the wonders of low power, wide field, deep sky observing, which with Night Vision is spectacular.

Bob


If using Afocal I suggest the 80-102mm f5 refractors over the 6 inch F4 newt. The 6 inch F4 newt is already kind of a tall stack as it's meant for imaging and gaining inward travel. It's really crazy with the 67mm setup. Not practical in my opinion.

The 6 inch F4 is good with prime focus and a filter wheel. But I think it's a poor choice for afocal work.

I think a 102mm F5 would be great though.

#21 Quartz

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Posted 08 September 2021 - 08:15 AM

If using Afocal I suggest the 80-102mm f5 refractors over the 6 inch F4 newt. The 6 inch F4 newt is already kind of a tall stack as it's meant for imaging and gaining inward travel. It's really crazy with the 67mm setup. Not practical in my opinion.

The 6 inch F4 is good with prime focus and a filter wheel. But I think it's a poor choice for afocal work.

I think a 102mm F5 would be great though.

 

I live in Bortle 8-9 and use a 6nm Ha filter. I had the 7 and I thought the 6 was “a tad better” and was worth it. I also use a 685 Pass filter for non-nebula objects. They are the only filters I use.

 

If you don’t have one, down the road you might also consider a small 80-102mm F5 achromatic refractor or 6” F4 Newtonian for very wide field, low power observing. The refractors are inexpensive and work very well with Night Vision.

 

You’ll soon discover the wonders of low power, wide field, deep sky observing, which with Night Vision is spectacular.

 

Bob

 

What kind of mounts are you guys using or would recommend for a refractor? I'm assuming this would be more for a grab and go? I like the idea of just going out for 30 minutes for some quick views. 



#22 stnagy

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Posted 08 September 2021 - 08:28 AM

What kind of mounts are you guys using or would recommend for a refractor? I'm assuming this would be more for a grab and go? I like the idea of just going out for 30 minutes for some quick views. 

For quick sessions with my 120mm refractor, I use the Stellarvue M2C mount on a Berlebach tripod. It's much more grab and go than using a goto or EQ mount. I usually leave the tripod, the scope, and a camera backpack with EPs and the NVD in my trunk. I can be observing in about five minutes. 



#23 bobhen

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Posted 08 September 2021 - 12:09 PM

What kind of mounts are you guys using or would recommend for a refractor? I'm assuming this would be more for a grab and go? I like the idea of just going out for 30 minutes for some quick views. 

I use 2 refractors for NV observing. One is my Tak TSA 120 which is also my general use refactor for the moon, sun and planets. It's also great on deep sky with my intensifier as a medium 900mm focal length scope. I can add a Barlow for 1800mm and a reducer for around 625mm and those focal lengths cover a wide variety of objects.

 

My other refractor is an inexpensive 102mm F5 achromat, and at 500mm native or around 350mm focal length reduced it is the scope I use for low power, wide field, night vision observing. 

 

I have a C8 for small objects (globulars etc.) or when I want more focal length. And I have a 50mm F3.75 guide scope that I use for ultra wide field, night vision, "handheld" observing. I had the 50mm out last night for a short handheld session. And even at my Bortle 8-9 location I was still able to easily see the large arc in the Veil Nebula

 

All my scopes used for night vision are used on simple, manual, alt/az mounts: A twin scope Desert Sky Astro DSV-3 or a single scope UA Macrostar. 

 

Below is my 102mm F5 refractor on the UA Macrostar alt/az mount (the Tak TSA 120 also uses this mount). A simple, lightweight, easy to set up, yet "very powerful" deep sky night vision scope/mount system for wide field observing. And yes 2 trips (maybe a 3rd if I bring out a chair) and you are ready to travel through the galaxy and beyond!

 

Bob

Attached Thumbnails

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Edited by bobhen, 08 September 2021 - 12:13 PM.


#24 GOLGO13

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Posted 08 September 2021 - 12:35 PM

I believe just about any grab and go alt/az mount would work for the 80 to 102mm F5. A Vixen Porta mount would work fine.

I use Unistar mounts, but they can only be found on the used market now.

What's also good about getting the 102 F5 is you get a wide field scope to compliment your larger newt. Could be useful for eyepieces as well as night vision.

#25 GeezerGazer

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Posted 09 September 2021 - 06:23 PM

Hmmm, definitely worth a try. How come it's so much cheaper through Ali Express? noticed their Optlong 7nm H-a is half the price as well. Definitely worth it if they're both the real deal, however I tend to be skeptical. Have you bought from them before?

Yes.  I ordered two filters from Laida Optics Store on 8-18-21.  They arrived in my mailbox yesterday, 9-8-21.  They appear to be the same Optolong filters I previously owned but sold.  I found myself in need of these filters again, so bought them from Laida this time.  I received at least 8 email updates on the shipping, including when it shipped, cleared sorting, cleared China's customs, arrived in US, cleared US customs, transferred to USPS, arrived at our local sorting center, out for delivery, and within minutes of actual delivery... that it had been delivered.  This was a first for such detailed tracking from a seller in China.  Impressive! 

 

As for the filters, they are nicely made and seem to perform well.  Sorry, too much smoke where I live in CA for a detailed report.  But my impression is that they perform just like the 685nm long pass filters I previously purchased from Agena... which is to say, they are just fine. 

 

If they are manufacturer seconds, I cannot yet distinguish a blemish.  Most of Laida's products are NOT sold at such a steep discount.  The on-line ad does not indicate that they are seconds.  Their packaging is the same as other Optolong filters I have purchased.  Them's the facts. 




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