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Old 18-10-2011, 07:47 PM
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Helix Nebula

I had my first observation of Helix Nebula (NGC 7293) over Melb last night (17/10/11) with my manual 12" dob. The only assistance was Stellarium on the laptop and S & T Pocket Atlas.

Around 10 pm, using Fomalhaut as a guide and star hopping to the north east, I was not seeing it no matter how hard a tried. At around mag 7, I knew it would be difficult over Melb skies. Kept persisting and then added my Astronomik 2" OIII to my 27mm TV Pan which was giving me X55 and bang there it was, dead centre in the eyepiece. Didn't get the marvelous colours or the details seen in all the photos, but there was a distinct grey circle, hinting at a central shape, filling about half the view. Tried with the 10mm Ethos at X150, but view was not as good.

I was wrapped to find and see it for myself. Looking at one of the closest neb to us, some 700 light years away. It was thrilling.

Clear skies

Rod
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Old 18-10-2011, 08:26 PM
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Woohoo,well done Rod!!!

Helix is a treat, try and see it under adark sky, it will jump out at you!!
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Old 18-10-2011, 08:51 PM
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Hi Rod,

Well done.
I've been told the OIII filter does make a difference, did you observe the same? did you try to view it with and without the filter?
I'm just curious to see how effective it would be from melbourne skies. are you a long way from the city lights?
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Old 19-10-2011, 02:30 PM
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Great stuff Rod

I remember when I first saw it through my 12" LX200GPS from outer suburban skies back in 02, was only just visible without a filter but the OIII reveled it nicely even the helix shape was glimsable
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Old 19-10-2011, 05:05 PM
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Thanks guys.

Alistair,
The neb was only just visible without the filter, but really jumped out using it. This is an expensive filter but so far is showing its worth. Similar result with Omega neb (M17), very small neb without the filter but showing up the clear omega shape with the filter. Will persist hunting down more neb.

Rod
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Old 19-10-2011, 06:41 PM
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Even cheaper OIII filters make a huge difference! I am really please I got an OIII filter - it has made backyard observing of nebulas a pleasure...
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Old 20-10-2011, 10:11 AM
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slightly off topic, I plan to get an OIII filter as well to use with my 8" F4 scope, but am stuck between choosing a 1.25" and 2" EP, both 68deg AFOV.

A 20mm 1.25 GSO superview EP or a 30mm 2" GSO superview. Not sure of the numbers, but the 20mm would provide reasonably better sized objects than the 30mm as the scope is only an F4 and as its 68deg, should be comfortable enough for viewing.
The 2" would be far better and you wouldn't have to shift your eye to cover the whole FOV, but then objects would be smaller.
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Old 23-10-2011, 07:55 AM
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mental4astro (Alexander)
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So cool, isn't it Rod!

The Helix is one object that does really surprise you on your first viewing of it. Such a distinct smoke ring. My first and so far only view of it was in June. While visible without a filter, an OIII does make it really stand out, and gives a more volumous shape to it. Cloud has made it impossible to have another crack at it. The Helix has been on my to-sketch list for some time. Scott Mellish has a sketch of the Helix on ASOD. He too used an OIII filter to bring out details.

My 1.25" OIII filter is the modestly priced GSO one. Does a brilliant job! Without it a lot of nebulae would be close to impossible to see from my home in Sydney. The most surprising part was seeing dark pillars in Eta Carina with my 8" f/4 scope (like Alistair's), from home. I could only see these from home with the OIII in this scope. I've recently purchased a 2" OIII filter for $100 on ebay from Omega Optical, the folks that make the DGM line. A dead-set brilliant filter for the price.

Alistair, this sketch will also give you an idea of what to expect with the 30mm Superview eyepiece in your 8" scope.
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Old 23-10-2011, 11:09 PM
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Thanks Alex,

looking forward to getting that OIII filter and giving the helix nebula a try.
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Old 24-10-2011, 03:40 PM
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Thanks Alex,

Eta Car is hidden behind the house at this time of year for me, but looking forward to summer when its higher. Also want get a good look at Orion neb, I hear that is also fabulous with an OIII. So next clear night I'm back out again.

Rod
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Old 24-10-2011, 04:32 PM
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Hi Rod, thanks for your report!

I had the Helix neb on my "to-do" list and then gave it away as I heard it was incredibly feint, so I thought oh what chance have I got from suburbia. But your report has re-ignited my interest to have a go. I'll be sure to only look for it using the OIII filter. Knowing this, has saved me valuable observing time trying to hunt it down. I didn't realise it was so BIG! Half filling up the fov on a 27 Pan, is something to behold! Oooh I can't wait now..
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Old 24-10-2011, 04:56 PM
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Quote:
Originally Posted by alistairsam View Post
slightly off topic, I plan to get an OIII filter as well to use with my 8" F4 scope, but am stuck between choosing a 1.25" and 2" EP, both 68deg AFOV.

A 20mm 1.25 GSO superview EP or a 30mm 2" GSO superview. Not sure of the numbers, but the 20mm would provide reasonably better sized objects than the 30mm as the scope is only an F4 and as its 68deg, should be comfortable enough for viewing.
The 2" would be far better and you wouldn't have to shift your eye to cover the whole FOV, but then objects would be smaller.
Hello ---- I don't know your first name?

My 2c worth...

Go the 20mm GSO- at that f/length, it will be used a lot. Your 30mm probably won't get a lot of use (I know mine doesn't), tho still a useful addition to the kit never-the-less. The 30mm is mainly good for w/field views for finding things. So if you are going to filter anything, I'd be throwing the filter on the 1 1/4 eyepieces. I find the 14mm range also a necessary focal length which I use mostly.

Regarding an OIII filter on M42 (The Orion Neb.), in my experience from having used both the UHC and the OIII, I find the UHC does a better job with contrast and bringing out the dark structures. The OIII made it brighter (I believe that's the oxygen rich area thru the middle of the neb )- but didn't offer the best contrast, re: structure of the wings and fish's mouth. This nebula has an awesome greeny tinge at lower powers. My next obs of, I have to see if I can hunt down some pink in it- apparently it's there!
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Old 24-10-2011, 10:41 PM
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Oddly my 30mm gets the most use,
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Old 24-10-2011, 11:07 PM
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Quote:
Originally Posted by Suzy View Post
Hello ---- I don't know your first name?

My 2c worth...

Go the 20mm GSO- at that f/length, it will be used a lot. Your 30mm probably won't get a lot of use (I know mine doesn't), tho still a useful addition to the kit never-the-less. The 30mm is mainly good for w/field views for finding things. So if you are going to filter anything, I'd be throwing the filter on the 1 1/4 eyepieces. I find the 14mm range also a necessary focal length which I use mostly.
Hi Suzy,
Its Alistair.
thanks for the info, its pretty much what i concluded as well,
Alex, i'm guessing your 30mm gets the most cause you love widefields!
i'm getting a 2" 26mm Agena EP (70 deg FOV) from the classifieds here.

If I can get a 2" OIII filter I'll try it with the 26mm, else will get the 20mm 1.25" EP and a 1.25" OIII.

after all this talk I can't wait to catch some views as well. but if only we had clear skies, sigh.

I will do some reading, but what type of nebulae are good with OIII amongst the different types of nebulae, planetary, emission, reflection or the others?
same with Ha filters? what type of nebulae would they be used with?
once I understand that, I'd know what type of targets to look for and what filter to use.

thanks
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Old 25-10-2011, 01:56 AM
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Alistair,

Some food for thought.. if you want to bump up the mag on those targets, and many from what I understand take higher mag well, that 2" filter wont carry across your 1 1/4". Higher mag eyepieces don't come in 2". I didn't know that when I first bought my scope and spent lots of $$ on a 2" barlow.. Just something to think about.
I'm not a big expert when it comes to pn's but I know with the Ring neb (M57) takes a 10mm very nicely on my 10" dob (I see you have an 8" ?), the Ghost of Jupiter takes a 15mm nicely, and the Orion Neb looks amazing in a 15mm and a 10mm. Just a couple of examples.
My advice (whether taken is completely up to you of course), go the 1/4" filter for now, get the 20mm ep in a 1 1/4" and then later if you still find you want it, go for the 2".

As for your request, your wish is my command, so here you go.

http://www.eaas.co.uk/cms/index.php?...-zone&Itemid=8


http://www.lumicon.com/astronomy-acc...d=1&cn=Filters


And my favourite one: http://www.raycash.org/filters.htm

Knock yourself out!

Last edited by Suzy; 25-10-2011 at 02:10 AM.
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Old 27-10-2011, 05:00 PM
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wow, thanks for the links Suzy, that's a lot of information and very helpful.
But are they for northern targets? I can see some are visible from the Southern hemisphere.

I will be getting the OIII for sure, will hunt out those fuzzies. just adding some setting circles for my Dob mount.
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Old 27-10-2011, 07:26 PM
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Like Alexander, I have the modest 1.25" GSO OIII - and it has been a great addition to my scope! Well worth it!!
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