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H-Beta Filters

John

By John
in Discussions - Eyepieces

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John

John

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I'm thinking of getting an H-Beta filter for the winter months to give the Horsehead nebula a try when my 12" newtonian is up and running, under dark skies of course.

I've been looking around at what's available and all the ones I've found seem to be intended for imaging wheras I'm purely a visual astronomer.

Are there visual and CCD versions of H-Beta filters, as there are for other narrowband filter types or will the H-Beta filters on offer serve both purposes equally well ?

Thanks :smiley:

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John

John

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Thanks Keiran :smiley:

I've looked at lower cost options than the Astronomik and Lumicon ones to be honest though I have an Astronomik O-III and it's superb, though costly. Rother Valley Optics sell the Lumicon H-Beta for £97 for the 1.25" size but I really need a 2".

365 Astronomy do a Skywatcher H-Beta in the 2" for a reasonable price but that is described as a CCD filter:

http://www.365astronomy.com/skywatcher-hbeta-filter-2-inch-p-2945.html?zenid=ac3faf1985be4df2e45ae58ef578c4f2

Telescope Services do a 2" which seems to be OK for both uses now I read the blurb:

http://www.teleskop-express.de/shop/product_info.php/language/en/info/p4683_TS-H-Beta-Filter-2--fuer-Beobachtung-und-Fotografie.html

They also do the Baader H-Beta which does seem aimed at imagers:

http://www.teleskop-express.de/shop/product_info.php/info/p495_Baader-H-Beta-Filter---8-5nm---2-.html

I need to have a closer look at the band pass graphs I think and see what, if anything, is different about the ones that are said to be suitable for visual.

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Keiran

Keiran

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Im not sure if i would go with the SW one. I have the LP filter, it works, but it doesnt. It seems a little cheap, and doesnt cut the LP great at home but helps in a dark site :)

The TS one looks like a good price, but as you said you will have to compare the graphs.... Sorry i could help more. my knowledge stops there :)

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John

John

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Thanks for the links :smiley:

I've just been reading of somebody who has spotted this elusive object with a 6" newtonian and a regular UHC filter - under very, very dark skies ! His description of it was wonderful I think:

".....it's like trying to see a little bit of nothing with a little bit of less than nothing resting over it....."

Now theres a challenge :smiley:

I'm wondering now if I could get away with a 1.25" H-Beta filter used with my 13mm Ethos eyepiece. I think that would show enough sky (.82 of a true degree). More thinking to do !

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alan potts

alan potts

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A good question indeed. I don't understand these filters much at all. Anyone know a link " Astro filters for the brain dead ". I could do with reading up on this as I have thought about the same and the OIII myself.

If you need one of these for only 1 target it's expensive.

Alan

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Damo636

Damo636

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I have read that a H-Beta is the filter of choice for the Horsehead, but also that it can be done with an O-Ill, especially the ones with the broader bandpass like your Astronomik John. I haven't tried the Horsehead with any real conviction but the California Nebula (another that apparently stands out best with a H-Beta) really pops with my relatively inexpensive Skywatcher O-lll. It might be worth a try before shelling out a lot of money for a filter that is useable on such a limited number of targets. This guy also seems to think the same.....

http://tech.groups.yahoo.com/group/starmaster_scopes/message/12421

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John

John

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Interesting stuff folks - thanks for your thoughts :smiley:

The chap I quoted in my previous post had glimpsed the Horsehead with his 6" scope using an Orion Ultrablock (is that the one you have now got Robin ?) so clearly an H-Beta is not the only way to do it, as your post also suggests, Damo.

I had an Ultrablock a couple of years back and thought it a very good UHC filter.

Thanks for the info in exit pupil Shane. Looks like the 20mm and 31mm Naglers would be the optimum tools with an F/5.3 scope.

Lots to think about and I think I'll hold back from splashing any cash for a while yet.

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John

John

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I believe this object does need very dark skies. From the descriptions I've read from folks who have seen it, a decent view of the Flame Nebula is a pre-requisite for standing any chance with the nebulosity that the dark mass of the Horsehead is projected against.

First test: see if I can see anything of the Flame neb !

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John

John

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My research on this tonight has thrown up this very interesting web page:

http://home.ix.netcom.com/~bwilson2/barbarasweb/MEyepiece.htm

I'm now thinking about a 25mm plossl + a 1.25" H-Beta Filter :smiley:

The information I've picked up so far has emphasised the importance of combining the "right" exit pupil with the most effective filtration.

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Mark at Beaufort

Mark at Beaufort

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John I have a 1.25" Thousand Oaks H-Beta filter and it certainly dims the view. I have tried many times to view the HH and the California Neb with this filter but have not been successful yet.

I have just obtained an adapter to screw 1.25" filters into 2" EPs so will have a go at the California Neb with the 26mm Nagler. I am likeky to have some vignetting but I will get a larger FOV. With regard to HH I used the 13mm Ethos with the filter but as stated above not seen as yet.

The webpage on the 'magic eyepiece' is an interesting read. I will certainly have a go with my Antares 25mm plossl with its 52 degree optics. I have a feeling once seen you will be able to return to these objects with more success.

John I will be interested how you get on.

Mark

PS - since posting my reply I have read this webpage in more detail - http://www.karmalimb...lters-findD.htm

It is interesting because my Thousand Oaks H-Beta filter is mentioned as a group A type. If the information is accurate then my 13mm Ethos with its exit pupil of 2.7 on my 10" Dob would not be the best EP for the job of seeing the HH. I can appreciate wanting to remove Zeta Orionis from the FOV so perhaps the 25mm Plossl is best with an exit pupil of 5.3. We will see!!!

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John

John

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Thanks Mark - I'll keep in touch on this. The 26mm Nagler sounds ideal.

Have you managed to see the Flame Nebula by the way ?

The more I read about seeing the Horsehead, the more I realise that achieving it is going to be about a number of factors coming together at the right time / place as well as giving yourself a fighting chance with the right equipment.

Perhaps I should just buy that 22" dob on UK AB&S !.

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rwilkey

rwilkey

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Hi John, my Orion filter is not the Ultrablock Filter, it is just subheaded ' Narrowband Nebula Filter', a different animal methinks. Numbered 05584, also G 22079 PO 40659, made in Korea - well that's all the info on the pack apart from 'Orion'!

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Damo636

Damo636

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I tried last year for the flame nebula with an 8" dob but even with dark clear skies I couldn't detect it. Thanks to this thread, I have now discovered that I had been using the wrong star as a signpost, Alnilam instead of Alnitak!

Doh.....

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Moonshane

Moonshane

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Hi Mark

I am interested in the filter for 2" eyepieces to allow you to fit a 1.25" filter. do you have a link please? that said my 32mm Plossl would give me a 6.9mm exit pupil in my 16" dob - working on f4 x 1.15 for the paracorr so might be worth a go. might even get away with my 15mm Plossl at 3.26mm at my light polluted site.

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John

John

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I tried last year for the flame nebula with an 8" dob but even with dark clear skies I couldn't detect it. Thanks to this thread, I have now discovered that I had been using the wrong star as a signpost, Alnilam instead of Alnitak!

Doh.....

Ha - we have all been there Damo :smiley:

Diligently searching in the wrong place and then blaming the seeing conditions, scope, whatever but never our celestial navigation :embarrassed:

Switching between refractors and newtonians can cause confusion too - I've often been looking on the "wrong" side of a guide star - M1 seems to give me these problems each time I search for it :rolleyes2:

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Mark at Beaufort

Mark at Beaufort

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I am interested in the filter for 2" eyepieces to allow you to fit a 1.25" filter. do you have a link please?

Shane

This is what I purchased - bought it mainly to view the California Nebula with my 26mm Nagler. Not used it yet and I guess I might get some vignetting but at least I can use my 2" EPs.

http://www.365astronomy.com/filter-adapter-from-125-inch-to-2-inch-p-3065.html

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