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Hydrogen Alpha Filter

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#26 Quartz

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Posted 10 September 2021 - 08:53 AM

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. 

Awesome, sounds good, thanks for the feedback! I think I'll go ahead and make a few purchases then. I don't care about the shipping time since I won't have my nv tube for at least another 4 to 6 months anyway. Appreciate the feedback!



#27 Speedy1985

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Posted 16 October 2021 - 01:59 PM

Awesome, sounds good, thanks for the feedback! I think I'll go ahead and make a few purchases then. I don't care about the shipping time since I won't have my nv tube for at least another 4 to 6 months anyway. Appreciate the feedback!

Just following up, but if you did order from Ali, have you received your filters yet? 



#28 Quartz

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Posted 24 October 2021 - 11:50 AM

Just following up, but if you did order from Ali, have you received your filters yet? 

Yep, I did. Came in pretty quickly, I want to say in just a few weeks and just as advertised.


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#29 Deadlake

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Posted 29 October 2021 - 07:36 AM

Has anyone used the Antlia 3 nm at all?

SQM is around 20.82 where I live.



#30 scoale

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Posted 29 October 2021 - 10:25 AM

Has anyone used the Antlia 3 nm at all?

SQM is around 20.82 where I live.

 

Has anyone used the Antlia 3 nm at all?

SQM is around 20.82 where I live.

I have.  I recently acquired the 2" Antlia 3nm pro.  I also own an Astronomik 6nm.  I've only had the opportunity to use the Antlia a few times , but my initial impression is that I am not seeing a significant increase in nebula visibility versus the Astronomik, and I prefer the overall view in the Astronomik. My skies are Bortle 8 and I am using a C11 @ ~ F/3 (AP .75 reducer and Televue 67 eyepiece.)  Again, these are initial impressions and I do plan on continuing to experiment with the Antlia.  Hope this helps.


Edited by scoale, 29 October 2021 - 10:26 AM.

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#31 Deadlake

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Posted 29 October 2021 - 11:23 AM

Given the Chroma is so expensive, lets rule it out. This leaves the Anitla Ha 3 nm is in stock and the Baader 3.5 nm @ F2. 

Any one compared the Baader and the Antlia? 

Ps: Since I was last here, filter threads have been multiplying. Maybe we need to update the master threads with some comparison of the new filters that are available?


Edited by Deadlake, 29 October 2021 - 11:23 AM.


#32 Joko

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Posted 29 October 2021 - 12:01 PM

Hi Deadlake,

In a dark sky, i don't see any difference between Antlia H-alpha 3nm and OVNI nebula filter (7nm).

In a light polluted sky, i see more details on nebulae with the Antlia 3nm.

Same results with the former Antlia H-alpha 3.5nm.

It seems that better is the sky, less noticeable is the difference, this is also something I read on CN few months ago but i can't find the post anymore.

Hope this helps.


Edited by Joko, 29 October 2021 - 12:15 PM.


#33 GeezerGazer

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Posted 29 October 2021 - 12:36 PM

A quote from previous testing:  "Understanding how filter placement in the optical system effects performance may help those who are considering the purchase of a narrower band (~3nm) filter.  If the optical system is too fast, a 3nm filter may not perform well.  On the other hand, if the optical system is too slow, increased scintillation/noise will result.  Between f:2.8 and f:5.6 seems to be a sweet spot for these very narrow filters when used rear-mounted.  When used front-mounted, the fastest optical systems do provide best H-a contrast on-axis, with the caveat that a bigger portion of the FoV will be pushed out of phase than when using a 5-7nm filter."  

 

Nearly all filter placement with a telescope uses a rear mounted filter, meaning that the filter is placed after the primary objective but before supplemental optics such as Barlows, reducers, or eyepieces.  

 

This is a link to the full thread with test photos:  

https://www.cloudyni...ilter-position/

Ray



#34 Deadlake

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Posted 29 October 2021 - 01:37 PM

Talking to other people the Antila are tested to 1/16 wave whereas the Baader are tested to 1/4 wave and a bit of an unknown quantity at present.

Speed of scope will be F6 native using a Tele Vue 55 mm Plossl. The scope will be close but not running at F2 native of device Antila seems way to go.

#35 ButterFly

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Posted 29 October 2021 - 03:35 PM

I was at a Bortle 3 site yesterday.  M33 was visible when it was high up.  I had the Baader UHC-S, Astronomik 6nm, and Antlia 3nm Pro in the wheel, after the Paracorr, in my 15".  The cone to the filter is about f/4.78.  There was a 67PP screwed onto the wheel, with a PVS 14 on that.  My EBI is 0.1.

 

The transmissions on both the 3 and 6 are very high.  There is no noticable difference in the brightness of the emissions portions.  It is the darks that get darker with the 3nm vs. the 6.  I consider the Baader UHC-S as an Astronomik 642, with even darker barckgrounds than the 642, and more blue pass from the stars.  There are typically fewer stars with the UHC-S vs. the 642, depending on color.

 

Wizard Nebula (SH2-142, NGC 7380):

The UHC-S shows the ridges of the first two mountain peaks, and hints of the third double peak off to the side.  The 6nm clearly shows the first two peaks, clearly shows the third double peak, and the veil in the background between the two peaks and the double peak.  The 3nm improves the double peak the most, showing the bend between the double peak more easily.  That's because the dark portion inside the double peak is darker.

 

Nessie Nebula (SH2-86, NGC 6820):

There is a Loch Ness Monster with its head in the cluster, a long neck with a slight curve, and a rounded body about as long as the neck.  A dark lane cuts through the nebula almost parallel to the neck, then forks under the body, and further off to the left.  Here again, the 3nm darkens the lanes.  That makes more of the body stand out.  The UHC-S here is mostly cluster, with slight nebulosity around it, with only the head being highlighted.

 

Elephant Trunk (IC 1396A):

I'm referring to the big, long dark lane here.  The UHC-S does nothing here.  With the 6nm, the big lane is almost broken into two separate dark nebulae.  Long narrow channel on the outside, and big bulbous head on the other.  I can still tell that between them is less bright than the surrounding nebulosity, but the dark is still rather bright.  The 3nm helps darken the lane, showing that the dark lane is clearly connected.  It's still not as dark as some of the darker nebulae in the region.

 

Cygnus:

Again, it's the darks that get darker.  It makes it easier to see the edges, and some of the wispier, fainter portions, just outside the edges of the emission portions.  All of Cygnus is a giant HII region, so darkening the darks helps a lot here.  Near B347 and the immediately surrounding region shows lots of differnce, as it contains some of the darkest dark in all of Cyg.  The "stripes" (too lazy to find the DWB#) on the side of the Propeller Nebula are also especially helped out.  The North America/Pelican region shows slightly more mottling.  Very subtle differences in this region.

 

Offbanding:

The 6nm maintains brightness up to the edge when the wheel is rotated.  The 3nm clearly offbands when rotated out of view.  I'd estimate that about 5 degrees of the 40 degree AFOV is entirely offbanded.



#36 careysub

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Posted 29 October 2021 - 09:46 PM

I was just out looking west into the LA light dome (I live in the Inland Empire about 40 miles away from city center), very low in the sky at the Lagoon, Trifid, Eagle and Swan nebulas with the 3.5 nm Antlia filter through a 500 mm catadioptric F/6.3 Bowen lens. This is not a particularly fast lens, but it is light and compact for its FL, giving 18X or so. 

 

They all showed up very well, under what must be considered very bad conditions, with the low altitude and high light pollution. I could see them well enough with 7 nm, but quite significantly better with 3.5 nm.

 

And now, a 1 AM Orion Nebula was was spectacular with the 3.5 nm Antlia and the F/6.3 Bowen as expected, but an easy target high in the sky to the east, away from the direction of the urban center. Flame Nebula was visible too.

 

Since I am using it with wider lenses I have it in the more affordable 1.25" format using the RAF Camera threaded ENVIS rings epoxyied with West Systems G-Flex into the adapter. SInce it is the best performing nebula filter I have I will eventually get the 3.0 nm and expect to see some further enhancement, not too bad in 1,25" (considering the cost of the Mod 3). 3.5 nm was what I could get early in the pandemic. 

 

My purchase of the Mod 3 was fortunately timed - just before the pandemic grounded me and kept me confined to home for more than a year.


Edited by careysub, 30 October 2021 - 08:09 AM.


#37 hoof

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Posted 29 October 2021 - 10:43 PM

I got the Antlia 3nm a few months ago. Put it in a filter wheel with my Baader 7nm. Both are 2” and the filter wheel is on one end of a TV 67mm plossl, inserted into the focuser of my 15” F/4.1 dob. I live at the edge of suburban Seattle.

No contest, the 3nm is much better at cutting out non-nebula lights. The Cygnus complex is more detailed and the veil is awesome, The Baader is nice, but washed out due to extra light. This is apparent flipping between the two filters. it’s like a veil if light being removed when I switch from the Baader 7nm to the Antlia 3nm.

For me the 3nm wad a good purchase, making h-alpha viewing another notch better.


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