nebula filter?

[lateralus]

I'm looking at purchasing a nebula filter for my scope. I have a 12" f/5 dobsonian, and I'm rarely able to get out to dark sky sites:mad2:.
So! What would be a sensible choice considering these circumstances?

Also, what would the contrast be like with the filter you suggest for my scope?

Thanks!:)

P.S. I'm not exactly rich, so something in a sensible price range what be good!

[Starkler]

There is much written about filters. There are different types with varying degrees of effectiveness on different objects.

Have a read of this, it pretty much says it all.

http://www.prairieastronomyclub.org/filters.htm

[jezza]

Thanks for the link to info on Nebula filters. Very enlightening. I had a related question. Cheers

[janoskiss]

Best value is the DGM narrow band-pass filter. Darkens everything except the gases in nebulae. I found it excellent in light polluted Melbourne. E.g. Swan neb. Can hardly see it without filter, but stands out clearly and shows a lot more structure through the filter. I found the filter to be of limited use under dark skies.

[janoskiss]

You will find a comparative review (one person's opinion) of 26 different nebula filters in the August issue of Astronomy:

Phil Harrington, Astronomy, Aug 2005, vol. 33(8), pages 82-85.

If you can't locate a copy and want to have a read, PM me.

[janoskiss]

One more post and that's it. Promise.
dhumpie has a Lumicon UHC for sale at a bargain price. These are supposed to be excellent too.

[iceman]

I can concur with the DGM Optics Nebula Filter - a very good price for a very good filter. About $100 cheaper than a new Astronomik/Lumicon OIII/UHC filter.

Are you after a nebula (narrowband) filter, or a skyglow (broadband) filter?

[Starkler]

I have a Lumicon UHC and it works well in dark skies also :confused:
In light poluted skies I have to drape a cloth over my head to shield ambient light to get the full benefit.

[iceman]

I agree with Geoff, I find the nebula (narrowband) filters to work equally as well under dark skies.

[Striker]

Dont forget the Baeder UHC-s filter.

I used it on My Orion images....and will be taking it to lostock to see how it goes under darker skies.

I have both the 1.25" and 2" version..I probably want need my 1.25" anymore if your interested.

If your intested in the 1.25" $90 includes postage.

it's virtualy Brand new.

[janoskiss]

I didn't mean they don't work. I meant they usually don't show you more than the unfiltered view. Under dark skies I only use it on fainter objects occasionally to show me if I'm looking at a nebula or an unresolved star field.

[ving]

ditto steve...wel i only have a broadband, but i still only use it on the faint ones :)

your light pollution must be shocking tho, i find the swan is quite bright (as long as theres no moon of course ) :)

[janoskiss]

Yes, it's not too bad with no Moon. But it really stands out with the NPB filter Moon or not. Funny thing is though that I just don't bother deep sky observing from the back yard all that much any more. It seems a futile exercise when I consider how much more I can see at a locations even only 45 minutes' drive away.

[Dobman]

Where can you get the DGM NPB filter from in OZ and who stocks the Orion filters?

[iceman]

Hi Simon.

You can't get the DGM optics NPB filter in Oz - you have to order it from overseas. The 1.25" version was shipped to my door for AU$80 - a bargain when compared to the very similar in performance Lumicon and Astronomik UHC/OIII filters for AU$190.

Just go to the DGM Optics (http://users.erols.com/dgmoptics/) site and order online. They were on sale when I got mine, i'm not sure how much they are now but it'll still be significantly cheaper than the more expensive brand.

[Dobman]

Thanks Mike, I've already sent an email. Hopefully it hasn't gone up much:thumbsup:

[Dobman]

Sent off email to DGM & got reply back within 24 hours (on a weekend too!) Dan @ DGM sent me a link direct to the filter ordering page. us$89 incl post (AU$115) Said it will be shipped within 24 hours. Great service & friendly too. He wished me good viewing
I ordered this filter on the strength of 2 reviews- one in Astronomy mag & one on cloudy nites. At this price it seems like a great deal compared to the cost of most filters thru Oz dealers. Has anyone used this filter?

[janoskiss]

Yes, I got mine from DGM too, no probs (1.25" version). It works very well, and it is quite impressive to see nebula appear from the murky skies, but once I got over the initial excitement, I haven't really used it very much. It is best for cutting out light pollution around nebulae, but I don't bother to observe much deep sky from the back yard. I rather drive to dark skies, where I usually prefer the views without the filter. I do use it for one purpose though, under dark skies: to distinguish between nebulosity and unresolved star fields, usually around the LMC.

[iceman]

In my opinion, it's much more than a light pollution filter - in fact I wouldn't call it that at all.

While it's true that it will most likely help to view nebula from light polluted sites, at dark skies it's equally as useful as the view WITH the nebula is considerably different than WITHOUT the nebula. They're different views - I think it's worth seeing a given nebula in both ways, as to my eye, they show different detail.

The view of the tarantula NGC2070 or NGC366 (I think?) are just superb when viewed with this filter - a much different view than without the filter. And this view was at a reasonably dark site, in both my 10" scope and hector (20" scope).

[janoskiss]

Yes, I imagine the filter would be more impressive in a larger scope. It does darken the sky and stars a lot and the nebula only a little, so it's a targeted contrast booster and can bring out detail you would not see without it. Even though I rarely use it, I don't think I'll ever sell it because it works so well. I'm looking forward to trying it out in my 16+" Dob one day. :dream:

[BerzerkerNerd]

:drink:
Hi Lateralus and everyone- i am noo to the forums- So please be gentle.
I own the Astronomik UHC in the 1 1/4"- I love and cherish it, it has a special container that secretely rests under my pillow at night- when i can not be not outside using it !!
Seriously though, over the recent moon cycle, on the wane with about a half or more moon, finding nebs was tough,- so, I wack the filter into the widest field EP I have at hand and search. Hey presto, with the UHC screwed into the EP you will then find Turantula, Carina, Orion, Crab.. (joking) anyhow the more popular nebs. The only drawback is the stars in the nebulosity taking on a peculiar greenish tinge- but the gas tendrils and filiments really do come out to play with your bio-optics. At around $180 the astronomik isnt a cheapy but not that excy' either, and please it really is worth scrimping for the extra money for this filter, my scope is a 10" Dob. Reflector 1250 F.L at F5. Skies here at Toogoom 25 Km north of Hervey bay are pretty good- Saturn and Jupiter at 420X around 2.30 am on calm mornings. Life could be worse, but the postage cost on equipment mounts up. In short get the best nebular filter you can afford. It will be your friend and ally.

[janoskiss]

Welcome Nerdmeister! I never thought of trying the filter for cutting out moonlight scatter. Great idea! I will try it next time I'm at a dark site. :D

[BerzerkerNerd]

Yes there is nothing they can not do:not. But Jano' what you said earlier about differentiating between neb. and other objects in the LMC and SMC is where the filters come into their own. Under dark clear skies, the astronomik performs excellently on DSO and nebular in general, so we differ here on their use, but again it all comes down to personal gear, inclination and optical perception of the individual, which seems to vary dramatically from person to person.

[rumples riot]

I have a meade broadband filter and it works very well on the tarantula, Eta carina and the swan in light polluted skies. Just my opinion.

[Merlin66]

M Gavin has tested the performance of various filters using a spectroscope.
Shows EXACTLY what is happening and which wavelengths are being transmitted/ blocked well worht looking at. When I get some time (!!) I'll do the same for the filters I have.

//home.freeuk.com/m.gavin/grism.htm

If this link doesn't get you there, go to his home page and look at the LH list near the bottom.

[acropolite]

I've got the DGM NPB as well, I agree with Mike & Steve.:D

[Dobman]

Just got my filter in the mail today:) . Cant wait to try it out. The next Bridgenorth viewing nite is coming and the weather is looking good so far( that could change in a blink here in Tas tho!!)
First lite has to be on M42 ( what else!) I'll post my initial thoughts after the weekend
Clear Skies
Simon:drink:

[iceman]

Good to hear.

Wavelandscott and I had a chance to try out his Astronomik CLS filter vs my DGM NPB on Saturday night.

While on M42 they appeared to do a similar job, Scott confirmed that on Eta Carinae, the DGM NPB showed much more nebula. So it's worth remembering that some filters work better on some objects - it depends what type of gas they're emitting.