2" Narrowband Filter Choice

[John]

Having invested quite heavily in a couple of 2" eyepieces now I think it's time to invest in a 2" narrowband filter to use with them - we are talking about visual use here rather than imaging.

Up to now I've been happily using a Baader UHC-S filter in the 1.25" format and I could just buy the 2" version of one of those.

I'm aware though that there may be other, better choices about these days and I wonder what other recommendations people might have. My scopes are 4" and 8" aperture which needs to be taken into account - I've found OIII filters a bit too severe for my taste which is why something like a UHC is what I'm aiming for.

The TS (Telescope Services) UHC filter seems quite reasonably priced in the 2" fitting - the bandwidth transmitted by it looks a bit narrower than the Baader UHC-S, more like a Lumicon UHS. Has anyone tried a TS UHC filter ?.

Astromik seem to be generally well regarded - which of their range might be worth considering ?.

Thanks,

John

[russ]

Well after weeks of researching i've just ordered the Orion UltraBlock 2" from SCS. There's a real lengthy discussion on Cloudynights about narrowband filters and the general consensus was if you can't afford the best filters on offer, then buy the Orion UltraBlock. Best of all, its the cheapest 2" option on offer at £68.

Russ

[bern]

The Astronomik UHC is well worth considering as it also passes Ha in addition to Hb and OIII. IMHO it's probably the ultimate UHC filter for larger scopes, ie 8"+.

The TS UHC looks good on paper, I'll have one in a few days so can advise better then.

For < 8" scopes I prefer the Astronomik UHC-E or Baader UHC-S

bern

[John]

.... Best of all, its the cheapest 2" option on offer at £68.

Thanks Russ - can I ask where ?

John

[John]

The Astronomik UHC is well worth considering as it also passes Ha in addition to Hb and OIII. IMHO it's probably the ultimate UHC filter for larger scopes, ie 8"+.

The TS UHC looks good on paper, I'll have one in a few days so can advise better then.

For < 8" scopes I prefer the Astronomik UHC-E or Baader UHC-S

bern

Thanks Bern, I'd like to know what you think of the TS UHC when you have had a chance to try it.

What's the difference between the Astromik UHC and the UHC-E ?

John

[bern]

You can see the filter graphs here http://www.astronomik.com/english/enghome.html

Basically the E version gives a wider bandpass for smaller scopes.

I reckon I'll sell the TS UHC for about £60 inclusive of delivery, subject to a satisfactory test of course!

bern

[russ]

John, the Orion is sold by SCS. I'm no expert on filters, in fact no nothing about them. So i'll defer to Bern's expertise on these matters.

But here's the CN thread with lots of input:

http://tinyurl.com/4xxzql

Hope it helps

Russ

[Andrew*]

I just got 2" Orion UltraBlock in the post today, after, like Russ, researching for quite some time. It seemed to be about as good as Lumicon and Astronomik, but alos about half the price! Especially good deal at SCS...

I will let you know how I get on with it.

Andrew

[ngc2403]

A word of warning about astronomik filters,

the things stated on their website are well to be blunt lies, however you do get what you pay for.

if you follow the stuff on the website then you would be lead to believe that the larger band pass is better however for narrow band imaging this is wrong. Narrower band filters have better contrast and blacker background which makes them far better.

- I've found OIII filters a bit too severe for my taste which is why something like a UHC is what I'm aiming for.

Astromik seem to be generally well regarded -

things like the veil are best seen through narrow band O[iII] filters and the north american is best seen and image with a narrow H alpha filter.

this is because they are large nebulae and have a low surface brightness so to see them you need a black background / dark sky site.

ally

[John]

Thanks for the tips Ally

I've owned and sold a couple of OIII filters - I just can't get on with the views they give - probably a personal thing !. They were however both Baader OIII's which I now understand have a narrower band pass than other OIII's - who knows maybe I'll give another OIII a try ?.

Of course I want it both ways - enhanced contrast of the DSO AND some background stars twinkling prettily

I guess it's truly dark skies that I should really be searching for !.

John

[John]

The Astronomik UHC is well worth considering as it also passes Ha in addition to Hb and OIII. IMHO it's probably the ultimate UHC filter for larger scopes, ie 8"+.

The TS UHC looks good on paper, I'll have one in a few days so can advise better then.

For < 8" scopes I prefer the Astronomik UHC-E or Baader UHC-S

bern

Thanks Bern, I'd like to know what you think of the TS UHC when you have had a chance to try it.

What's the difference between the Astromik UHC and the UHC-E ?

John

A quick update - I'm going to try a 2" TS UHC filter as supplied by Bern at Modern Astronomy - I'll be interested to see how it compares with the Baader UHS-C and I'll post my findings

John

[themos]

bagsy your old 1.25" UHC-S?

[GazOC]

I got a good deal on 2" UHC-S from Omega Optics on Ebay. Its not quite as sharp in the cutoff as the Baader 1.25" inch I had but for visual use thats not always a bad thing.

[bern]

I got a good deal on 2" UHC-S from Omega Optics on Ebay. Its not quite as sharp in the cutoff as the Baader 1.25" inch I had but for visual use thats not always a bad thing.

Gaz,

I tried an Omega Optics UHC type filter a while ago, against a few others that I had, it just didn't seem to perform as well :?

Was with a Watec camera rather than visually though.

bern

[GazOC]

I had it side by side with the Baader for a couple of weeks and while you could see more definition using the Baader, a lot of objects benefited from the fact the Omega let through more light. I'd guess this is less of an advantage when you are integrating frames though?

I would think it would be a good filter to try on scopes that are usually too small to take this sort of filter.

[bern]

Makes sense Gaz, the Watec is also more sensitive to Ha than the eye, which can confuse issues.

bern

[John]

Well I've been able to give the TS UHC filter a good workout tonight and so far it's performed very nicely. Just as good as the Baader UHC-S in my 4" frac and a tad better than the Baader with my 8" dob.

Managed to see the Owl Neb and E&W parts of the Veil using the TS UHC with my 4" frac which is pretty good going around here.

The Eastern part of the Veil looked superb with the 31mm Nagler and the 8" dob 8) .

Thanks Bern

John

[bern]

Thanks John, I guess you won't be sending it back then

bern

[John]

Thanks John, I guess you won't be sending it back then

bern

Nope

John