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NV MOD3C with Baader and Chroma Ha filters

NV observing report
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#1 slavicek


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Posted 10 July 2019 - 08:21 PM

Here is brief filter report from my recent NV observing night.


Sky: Bortle 5, 1/4 Moon
Set up: See picture
2x MOD3C white phosphor, filmless with
2x 75mm f1.8 Kowa lens (effective aperture 41mm each) modified for 2" filters. FOV=13 deg
Wilcox military helmet with dual MOD3 mount and 5lb counter weight (those Kowas are heavy)
Ha Filters: Baader 3.5nm (2x), 7nm (2x), Chroma 5nm (2x)


Before I began my observation my guess was that since I am observing from light polluted place the 3.5nm filter will perform best.
So, by panning around the sky (moving my head) I've looked at and I could see these nebulas:
Cygnus - North American, Pelican, Gamma Cygni, IC1318, and Veil
around Sagittarius (half way between Saturn and Jupiter) - Eagle, Swan, Lagoon and Prawn
To my surprise the 3.5nm Baader gave me the "weakest" view, or a view with least contrast. Next was 7nm Baader and the best view (= best contrast) was with the 5nm Chroma. However it could be that 5nm is the best filter for NV, rather than Chroma is higher quality filter than Baader. That I do not know. What I do know that at Bortle 5 sky I am using Chroma 5nm.
I do not (yet) take pictures of what I see, however the smart phone pictures of the above mentioned nebulas using NV (and which are posted elsewhere on CN) pretty much represent what I've observed.
I could not see any of the weaker Sharpless catalogue nebulas (in Cygnus and Sagittarius). I am curious whether I need darker sky or I need to use bigger telescope to see them. I plan to do just this in the future, so stay tuned.

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  • Jeff Morgan, Ptarmigan, moshen and 4 others like this

#2 The Ardent

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Posted 10 July 2019 - 09:20 PM

Nice setup! 

Try without the H-alpha for the dark dust lanes in the Milky Way. Majestic at 3x. 


With my 18” , Mod 3, and dark red 630 filter, the Ring M57 and Dumbell M27 show nice detail that is difficult for me to see without NV. 

The Trifid M20 is especially interesting with the dark lanes, in both wideband and H-alpha. 

#3 Jeff Morgan

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Posted 10 July 2019 - 09:47 PM

Nice set up!


The moon makes it tough - you're more intrepid than me. When the moon starts waxing, I'm usually winding down until Full + 3 days.


If you can get the Prawn the War & Peace (NGC 6357, aka Lobster) and Cats Paw (NGC 6334) should be possible, perhaps easy. I find them both to be brighter than the Prawn.


Try your luck in eastern Serpens too. While M16 draws the attention, nearby Sharpless 2-54, 2-64, and 2-68 are also quite good, probably comparable in brightness to the Prawn.

#4 alanjgreen


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Posted 13 July 2019 - 03:04 AM

Great report. I love the 5nm Ha filter for NV use too. I also agree that 5nm is good for “beating the moon” and it’s surprising what you can still see with the Devils Orb up in the night sky. 


The main issue with seeing the Sharpless objects is finding them. They are more likely to be found and observed with a GOTO mount and 4” frac then going handheld.


I have posted an excel spreadsheet in a couple of my recent observing reports that list nearby GOTO SAO star references to help anyone find them.


But as Jeff says, do have a look towards the southern horizon for M8, M17, M16, M20.


Try fitting two UHC filters on the front for some Milky Way observing too.



Edited by alanjgreen, 13 July 2019 - 03:05 AM.

#5 11769


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Posted 17 July 2019 - 05:20 PM



A 5lb counterweight is no joke. Good neck muscle exercise I guess. Views are always amazing at 3x. Both 1x and 3x and my faves for observing. 

#6 Clutch5150


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Posted 01 August 2019 - 11:52 AM

Heavy or not, great set up...  Definitely a lean back system and enjoy the night sky!

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