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GoodOleJim

Advice on nebulas

19 posts in this topic

Hello gang, I love your forum, and finally decided to make my own account and join the conversation.

I've been observing about two years, and I absolutely love it. It's become my passion, and I can't get enough of it.

I own an Orion 10" dob with a 1200 focal. I own a couple of the lower-end eyepieces that came with the scope, as well as a 30" GSO Superview 2" eyepiece. I just ordered a 2" 28mm Orion DeepView eyepiece yesterday.

 

I have a few amateurish questions. I love viewing Orion. It comes in great up here in North Dakota, my only problem is that I'm not seeing color within the nebula. I'm looking for advice on possible filters or eyepieces to aide in the process. I admit that I do quite a bit of my viewing within the city I live in, so light pollution is probably playing a part in that, but any advice is appreciated.

 

Thank you for allowing me to join your forum. I look forward to a long stay here!

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Hi ! Welcome to the forum.

Seeing colour is very subjective. I get a greenish glow from M42. Most of the bright planetary nebulae are blue or blue green. Some colours , such as " The Blue Snowball" in Andromeda are stunning. The " Eskimo Nebula" , NGC 2392 is up at the moment in Gemini and I get some colour with that. You should spot the centralwhite dwarf star in this one , along with the halo at x150-x200.

Best filter for general use is  the UHC. I use just a cheap SW one. It enhances the view , darkening anything else by blocking wavelengths that aren't emitted by nebulae. This will also enhance supernovae remnants like " the Eastern Veil" in Cygnus. It'll make a huge difference to M42.

Best views are from dark skies. Light pollution bleaches out contrast, but bright planetary nebulae are still observable, 

clear skies !

Nick.

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colour viewing is subjective. Some folks don't see colours in M42 even in a 300mm dob, others claim pink or green tint under dark skies in telescopes as small as 6". As for filters, UHC and OIII are a nice value, if you want to see a bit more. They also retain their value in second-hand market pretty well, if you decide, that you are not happy with the views they provide.

I read all there is about filters on this forum and on cloudynights and decided to pay a bit more and not wasting my time and resources with UHC-S or UHC-E and went for Astronomik UHC. I am happy so far, but I don't know how much difference there is between UHC-S and UHC-E and UHC, because I've seen the nebula only through UHC. So really can't tell if the price difference is adequate to viewing difference. Almost all of the more experienced folks agree thou, that it's better to go for better filters in the beginning.
And welcome to the forum, enjoy your stay!

Edited by kilix

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seeing colour is tricky due to the way the eye works in the dark. I think it is harder in Light polluted sites, as the eye doesn't fully dark adapt and the nebulae appear dimmer; when i go to a dark site, I find that I can draw some subtle colour from some of the brighter ones - still tricky though and you have to sit and relax and really observe it.

there is a pinned thread somewhere, entitled "what can I expect to see" (I'm sure someone will link it for you soon), well worth a read.

and welcome to the forum :)

 

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A warm welcome from me too.

I find filters such as a UHC are excellent for pulling out more contrast and detail in nebulae, but I don't find that they help with colour (other than via any caste that they add themselves which is of course false).

Contrary to some of the answers above, I believe that a little local light pollution can help to see colour in M42. Not the washed out orange haze you get covering the whole sky, but some local streetlights which stop you getting fully dark adapted. If your colour perceiving cones are still firing, then you will see the colour.

I've seen it myself in anything from a 4" refractor to a 12" dobsonian. Not every time, but enough to know it is possible, and real.

Enjoy!

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Here's a link to the excellent article by one David Knisely of the Prairie Astronomy Club:

http://www.prairieastronomyclub.org/filter-performance-comparisons-for-some-common-nebulae/

D.K. is a true 'Filter-Nut' - as am I, and the information in this article is quite accurate indeed. But before you go off and spend 'Bucket's O' Bucks' on these, do a bit of research into the brands of filters, learn about things like 'bandpass-width', and a few other things.

Here's another article, also courtesy of David Knisely:

http://www.prairieastronomyclub.org/useful-filters-for-viewing-deep-sky-objects/

Dark-adapted eyes, as dark a place as you have - and can create - averted-vision - we'll get you to see colors! :p Though, as you likely know, the majority of deep-sky objects will appear as 'gray-smudges' regardless of filters or even apertures.

Oh - Greetings to you, Jim, from snow-covered Vermont!

Dave

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2 hours ago, GoodOleJim said:

Hello gang, I love your forum, and finally decided to make my own account and join the conversation.

I've been observing about two years, and I absolutely love it. It's become my passion, and I can't get enough of it.

I own an Orion 10" dob with a 1200 focal. I own a couple of the lower-end eyepieces that came with the scope, as well as a 30" GSO Superview 2" eyepiece. I just ordered a 2" 28mm Orion DeepView eyepiece yesterday.

 

I have a few amateurish questions. I love viewing Orion. It comes in great up here in North Dakota, my only problem is that I'm not seeing color within the nebula. I'm looking for advice on possible filters or eyepieces to aide in the process. I admit that I do quite a bit of my viewing within the city I live in, so light pollution is probably playing a part in that, but any advice is appreciated.

 

Thank you for allowing me to join your forum. I look forward to a long stay here!

Hi Jim,

Try using a blackout blanket over your head and the eyepiece. Observe the same object for at least 15 minutes before moving on to the next. As long as you leave breathing room your eyepiece won't fog up and you will greatly increase your dark adaption. I suspect the reason you can't detect the perlescent green hue in M42 is due to poor dark adaption. The bright and dark nebula as well as the colour will definitely be enhanced by blocking out stray light by using the blanket, and M42 will take on a 3D effect. It's a very effective and a very cheap way of improving the view. 

Mike

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As expected, the amount of advice didn't disappoint! Is their a particular brand of UHC any of you would recommend? I've looked at them before, but haven't pulled the trigger on one yet.

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Hi Jim!

I have a 10" Skywatcher - same focal length.  For my first two winters with the scope, I never saw colour in the Orion nebula.  I was using a 70° 15mm GSO eyepiece - my favourite for ages in that scope.

Then I took the plunge on a 13T6 Nagler.  Wow! I saw obvious strong green throughout Orion the first time I used it... expensive yes, but so worth it imho for the wonderful views on all manner of objects over the last 7 years.

Just my experience, all our eyes are different of course :)

I'd strongly recommend an O-III filter, for the Veil and planetary nebs (not for colour, but to make hard to see detail visible).

Best of luck

-Niall

 

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Hi Jim! I love North Dakota, the best steak I've ever had was in Fargo :thumbsup:

There are 2 things that will help see color, primarily green, in M42- #1- dark skies, #2 using a filter in dark skies. It is possible to see a very faint green in 19 mag skies with a filter though, I've done it myself.

I would cautiously approach buying a filter as they are expensive and can vary in quality even within "top" brands. My most recent purchase was a DGM Narrow Passband (UHC type filter) and am very happy with it and Dan McShane is great to deal with.

My story so far: 2 OIII's Lumicon and Astronomik, both very good, the Lumi is tighter and with more contrast but fussier on eyepieces.

                        Orion Ultrablock- I got a very poor example, chucked it out

                        Astronomik Hb- excellent

                        Lumicon Hb- not so good, its off for testing

                        Lumicon UHC- superb

                        DGM NPB- excellent, same or better than the Lumi UHC

Jim I would research Lumicons recent sale to Farpoint and see if the quality is back to where it was, this is just my thought... baseless really.

So far the DGM NPB appears to be a very good cost effective filter and is worth researching, along with Astronomik filters, IMHO.

http://www.npbfilters.com/order-usa.html

Edited by jetstream
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16 hours ago, GoodOleJim said:

The bandpass on these are too wide reducing their performance, so honestly I would not buy one of these. The bandwidth of the Celestron is about 60nm instead of an effective 23-27nm, such as the ones I mentioned above.

Edited by jetstream

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1 hour ago, jetstream said:

The bandpass on these are too wide reducing their performance, so honestly I would not buy one of these. The bandwidth of the Celestron is about 60nm instead of an effective 23-27nm, such as the ones I mentioned above.

The author above is quite correct. It's not really a UHC Filter. It's more like an Orion Skyglow-Filter. Which is fine for reducing LP (Light-Pollution) from Mercury-Lights and Sodium-Vapor lighting commonly associated with streetlights. But not the recent move to use LED-Lighting adopted by many places. But that's a different matter.

Just to add to Gerry's posting above: I do have an Orion Ultrablock. Mine isn't a poor one - it's a very, very good UHC (IMHO). Sorry that Gerry had bad luck on this.

Looking at the World Through #25 Red-Filter Glasses,

Dave

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Some great input above on this :icon_biggrin:

The only thing that I'll add is that I've noticed that younger eyes seem to detect colour in astro objects more easily than "oldies" like me !

When doing outreach events it's invariably the younger observers that notice colour in stars and deep sky objects wheras older folks are saying "well I think I can see that ...."

 

 

 

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Gerry -

I was recently in contact with one of the new owners of Lumicon, and I was acting as a conduit for questions along the lines of your wondering if their quality would be up & running soon. And were they planning to change the formulae of what went into the original Lumicon-Filters. And he assured me they would be exactly the same as they were as Lumicon.

Read it for yourself:

Lumicon_change_of_ownership_-_Vendor_and_Group_Announcements_-_Cloudy_Nights_-_2016-11-17_16.43.05.png

If this can't be enlarged and be legible, do let me know with a PM and I'll get it to you another way, please?

Anyway - he was quite open about the current business-plans and know we want to see the 'classic' Lumicon-Filters to remain available for subsequent generations.

Fear not!

Dave

 

PS - I have the permission of all parties in the enclosed thread from CN to pass it on as I see fit.

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For a nebula filter I suggest one of the UHC filter that transmit both Ha and OIII. Some only it seems do one yet carry the same name of UHC. Equally I suppose it also depends on the definition of UHC.

Have a look at this: http://www.astrosurf.com/buil/filters/curves.htm

If you scroll down you will see that the Astronomic UHC and the Lumicon Deep Sky both transmit both Ha and OIII whereas the Lumicon UHC basically just transmits OIII and no Ha. The Baader UHC-S passes both, and the Televue Nubustar filter is again more or less just OIII.

Makes selecting a UHC filter a bit of a problem as you really need to have the curves. You also need to know the nature of the nebula you are going to look at. Bet you thought that nebula observing was a case of point big cope at one, nothing is ever easy/simple. :icon_biggrin::icon_biggrin::icon_biggrin:

Cannot help on the color aspect, I do recall people some time back (3 or 4 years) commenting that it needed about 14" to get color out of M42. Then of course others reported seeing it in smaller scopes. So it is apparently subjective and additionally dependant on your sky darkness - assume Minot @ND is fairly dark (?). Looks like it should be otherwise a short drive on {2} or {83} should get to a dark location rapidly.

Does anyone do a 40mm 2" eyepiece ? Just thinking that a 40mm should give about 30x magnification around about a 2 degree view, That might frame M42 better and sort of concentrate the image (color) more. Just a thought.

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3 hours ago, ronin said:

Does anyone do a 40mm 2" eyepiece ? Just thinking that a 40mm should give about 30x magnification around about a 2 degree view, That might frame M42 better and sort of concentrate the image (color) more. Just a thought.

The 40mm will give a very large exit pupil @ f4.7... 8.5mm,too large really. Joe's 30mm,28mm or a 25mm plossl with give nice results with a UHC, NPB or OIII in his telescope at an exit pupil of 5.3mm for the 25mm plossl.

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The city of Minot holds around 60,000 citizens, so light pollution can be pretty significant at times. I make a habit of taking a night a week and loading up the gear for darker skies. North Dakota is pretty raw in the winter, so temperature has to be fairly mild to make it worth the trip. :)

 

I do a lot of summer viewing though. I'm starting to compile a list of things I'd like to look at this summer. 

 

I'm definitely in the market to add a good filter. Just trying to locate the right one. I've been researching Lumicon, and Dave's input has them back in the running. I just want to make an educated decision on this one. All suggestions are appreciated!

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