H-Beta Filters

[Moonshane]

cheers Mark - looks like another future purchase!

[Mark at Beaufort]

Shane as a follow up just in case someone decides to buy a 1.25" H-Beta filter and one of these adapters.

Its a sunny afternoon in Hereford and I have tested the adapter on my 66mm William Optics frac

20mm Nagler - no apparent vignetting

26mm Nagler - some vignetting but not a major problem

38mm Panaview - alot of vignetting with the eyepiece cup screwed it. Things improve with the eye cup completed wound out - this could give an okay view although I need to test it out at night.

Hope this helps just in case someone does not want to spend the extra cash on a 2" filter.

If people want to wait to SGL8 they are welcome to use the H-Beta filter and the adapter if that helps.

Mark

[Mark at Beaufort]

The information on various websites given in this thread gave me hope that I might find the HH with my H-Beta filter using a 25mm 1.25" plossl. I have produced a image from Stellarium matching my 25mm plossl on my 10" Dob. Image attached.

If you start at Alnitak there are 3 - 7+ mag stars above it. In between the star on the left and the middle star of the group is 3 - mag 12+ stars in a triangle. The one on the top right is close to the HH nose. I think if you can pin point these 3 stars with a dark transparent sky I might be successful. Well its worth a try.

The image below is that seen in a Reflecting telescope.

Mark

[Moonshane]

very cool mark - thanks! I'll be printing that methinks.

[Damo636]

Yep, me too, thanks for posting :-)

[Sarah]

Yes, thanks for posting Mark. It confirms what dawned on me earlier today, that I was looking in the wrong direction from Alnitak, when I tried looking on Saturday evening! And thanks for mentioning in an earlier post about seeing the Flame without Alnitak in the FOV. That is also helpful! I suspect our skies at home may not be quite dark enough, but I will give it a try!

[John]

Thanks Mark - very useful post

I've seen stars down to around mag 13.5 with my 10" from my back garden so there might be some hope with a 12". Extended objects and dark ones are much more challenging than point sources though.

You folks might get there first though as my 12" is not yet mounted and I've just sold my 10" !.

[Sarah]

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You folks might get there first though as my 12" is not yet mounted and I've just sold my 10" !.

You may have your 12" mounted before we get another clear night!

[John]

You may have your 12" mounted before we get another clear night!

Possibly, from recent weather experience !

It's clearish tonight but not really DSO-clear. Jupiter has been superb though

[rwilkey]

You can put a 2" filter in the 2" adaptor and place the 1.25" adaptor in and use 1.25" ep's, check your 2" adaptor has thread for filters though, as some don't. If you need extra length to stop the ep hitting the filter, use the Baader FTR's, 14 or 28mm, which both have 2" threads.

[Moonshane]

not sure if it's the same for Ha filters (and it's obviously a long exposure) but given this was taken under a full moon, perhaps there's hope for those in light polluted areas and larger apertures to see the HHN at our convenience with a Hb filter?

[Damo636]

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

I had a go at the Horsehead Saturday night/Sunday morning past with a Skywatcher O-IIl filter, and contrary to the above, found it to be of no benefit whatsoever viewing this target. I could see the Flame Nebula unfiltered, not that difficult actually, but even though I knew I was looking right at where the Nags head should be, I couldn't detect it. I tried both 21 & 31mm ep's, 4-6mm exit pupils, filtered & unfiltered, but it made no difference. Oddly enough, I didn't think the O-lll did much to enhance the Flame either!

Maybe a UHC might work better here? Anyway, as much as I had hoped to check this elusive object off my to do list, its not going to happen with an O-lll, at least not the Skywatcher version.

[Mark at Beaufort]

The Prairie Astronomy Club make this statement in their website about the o111 filter and the Horsehead Neb

IC 434 HORSEHEAD NEBULA (diffuse nebula in Orion)

(10 inch f/5.6, 52x, 71x, 104x).

DEEP-SKY: (2) Little change is seen from viewing without a filter. When visible, it appears as a weak dark gap in the dim north-south nebulosity, and the shape is hard to see. Nebula is difficult, unless viewed under very dark and clear conditions.

UHC: (3) Horsehead now stands out weakly from dim glow, showing some of the horsehead shape with averted vision, a definite improvement over no filter or the DEEP-SKY.

OIII: (0) No Horsehead seen. IC-434 nebulosity not seen for certain.

H-BETA: (4) Nebula still dim, but Horsehead shape now fairly easy to see, showing up with more contrast than with the UHC filter. East edge of IC 434 seems brighter than the rest of the nebula with the H-beta.

RECOMMENDATION FOR HORSEHEAD: Lumicon H-BETA (UHC also helps, but OIII not recommended).

So Damo636 I don't think it's worth trying the o111 filter again but maybe a UHC is worth a try.

Mark

[Damo636]

Thanks Mark, that would certainly back up my findings. It looks like there's no way around it, its going to have to be a H-Beta for the best view!

[Mike73]

Pretty much confirms what this filter review on CN states, pretty sure most of you have seen it before.

http://www.cloudynights.com/item.php?item_id=1520

IC 434 HORSEHEAD NEBULA (diffuse nebula in Orion).

DEEP-SKY: (2) Little change is seen from viewing without a filter. When visible, it appears as a weak dark gap in the dim north-south nebulosity, and the shape is hard to see. Nebula is difficult, unless viewed under very dark and clear conditions.

UHC: (3) Horsehead now stands out weakly, showing some of the horsehead shape with averted vision, a definite improvement over no filter or the DEEP-SKY.

OIII: (0) No Horsehead seen. IC-434 nebulosity not seen for certain.

H-BETA: (4) Nebula still dim, but Horsehead shape now fairly easy to see, showing up with more contrast than with the UHC filter. East edge of IC 434 seems brighter than the rest of the nebula with the H-beta.

RECOMMENDATION FOR HORSEHEAD: Lumicon H-BETA (UHC also helps, but OIII not

recommended).

[Damo636]

I hadn't seen that review Mike, good read, thanks for posting. I mentioned in my original post that I have seen the California Nebula with the O-Ill, I see now that I have got it confused with the North America Nebula, doh!

[John]

I had a go at the Horsehead Saturday night/Sunday morning past with a Skywatcher O-IIl filter, and contrary to the above, found it to be of no benefit whatsoever viewing this target. I could see the Flame Nebula unfiltered, not that difficult actually, but even though I knew I was looking right at where the Nags head should be, I couldn't detect it. I tried both 21 & 31mm ep's, 4-6mm exit pupils, filtered & unfiltered, but it made no difference. Oddly enough, I didn't think the O-lll did much to enhance the Flame either!

Maybe a UHC might work better here? Anyway, as much as I had hoped to check this elusive object off my to do list, its not going to happen with an O-lll, at least not the Skywatcher version.

Interesting report Damo. I had a peek at that area of Orion a few nights back. The transparency was very good but I only had my 4" Vixen refractor out so I thought I'd just familiarise myself with the star patterns in preparation for when my 12" is up and running. I saw no sign whatsoever of the HH or the nebula it is projected against however I did fancy that I could just see the slightest traces of the flame in the right spot. This was without a filter. When I put the O-III in there was nothing to see there.

This might have been "averted imagination" as it's been called I guess

It was good to have a visual wander around the area though, for future reference

My reading on filters for this object concurs with the earlier posts. H-Beta is preferred although the Orion Ultrablock or a similar UHC might give half a chance.

[alan potts]

I will be giving a coat of looking at when these clouds get out the way, it's like living in England. I don't know if it can be seen without filters but I am going to try anyway.

Alan.

[Moonshane]

This might have been "averted imagination" as it's been called I guess

one of my favourite quotes along these lines was one guy when looking at the Pacman nebula said that he could not tell if he was seeing it or remembering it! classic.