Choice of UHC Filter?

[Stu]

There are just too many reviews where the NPB and Lumicon UHC have been tested and the NPB has just edged out the UHC's in contrast. Even though the Lumicon UHC has the better OIII transmission the NPB still comes out on top, figure that one out!?

Seeing colour in M42 and noticing a huge cloud of gas around M17 were both things I had never noticed before with my old Astronomik UHC.

The NPB also delivers a more of a natural appearance, almost as if you aren't using a filter at all (although I think the new 'improved' NPB isn't quite as neutral as the old one).

I like seeing stars with my NPB, just look how many PN's have nearby OC's. Both Astronomik and Lumicon slightly dim those star fields.

The Lumicon OIII is still widely regarded as the best OIII but for me at least the NPB delivers views which the Lumicon UHC doesn't and cant.

I'm sure you are right there Mike. The Lumicon UHC is pretty close to the OIII (outside the inclusion of the Hb line of course) whereas others have a slightly more generous band pass which probably has benefits.

I've just received a DGM NPB filter but have yet to try it. The filter had a problem with it on arrival, but to their credit they immediately shipped a visually inspected replacement. Excellent customer service . Hopefully it should be here in a week or so.

Looking forward to giving it a go, as you say the OIII is great on the Veil and other similar objects but being able to see both the nebula and associated star cluster together is great.

[YKSE]

Excellent resources above.

David K does not rate the Astronomik O-III too much though which is different to my experience with them.

I think David Knisely main concern about Astronomik's filters are the wider pass band, as he expressed here

[Mak the Night]

I may have to wait a bit for a Lumicon UHC as there seems to be a paucity of them at the moment and the TeleVue NebuStar is being discontinued. Is the Astronomik UHC Deep Sky Filter comparable to the Lumicon as it is a similar price?

[John]

I agree with Mike73 on the Omega DGM NBP and Lumicon O-III filters, having bought his previous pair from him a little while back

The NBP filter did some very interesting things to M42 and is the first filter that I've really enjoyed using on that object.

I think David Knisely main concern about Astronomik's filters are the wider pass band, as he expressed here

Yes thats my take on his view as well. Personally I think it's a darn fine filter that works really well across a wide range of apertures

[Mak the Night]

Does anyone have any experience of using both the Lumicon Deep Sky Filter (LF3010) and the Lumicon Ultra High Contrast Filter (LF3025) and if so, how do they compare?

[John]

The Lumicon Deep Sky is a broadband filter rather than a narrowband as the UHC is. It's effects will be more subtle in terms of contrast enhancement. I've tried some broadband filters (Orion Skyglow, Antares ALP, Meade Nebula) and I thought their impact was very modest at most really. Nothing like the difference that a UHC or O-III can make.

[YKSE]

Personally I think it's a darn fine filter that works really well across a wide range of apertures

I can only second that

The Lumicon Deep Sky is a broadband filter rather than a narrowband as the UHC is. It's effects will be more subtle in terms of contrast enhancement. I've tried some broadband filters (Orion Skyglow, Antares ALP, Meade Nebula) and I thought their impact was very modest at most really. Nothing like the difference that a UHC or O-III can make.

That's my impression too by reading David K's filter comparison a  couple of times through and through, although I've not had any of them.

[jetstream]

There are just too many reviews where the NPB and Lumicon UHC have been tested and the NPB has just edged out the UHC's in contrast. Even though the Lumicon UHC has the better OIII transmission the NPB still comes out on top, figure that one out!?

Seeing colour in M42 and noticing a huge cloud of gas around M17 were both things I had never noticed before with my old Astronomik UHC.

The NPB also delivers a more of a natural appearance, almost as if you aren't using a filter at all (although I think the new 'improved' NPB isn't quite as neutral as the old one).

I like seeing stars with my NPB, just look how many PN's have nearby OC's. Both Astronomik and Lumicon slightly dim those star fields.

The Lumicon OIII is still widely regarded as the best OIII but for me at least the NPB delivers views which the Lumicon UHC doesn't and cant. 

I thought the color was from a "red" leak in the NPB's spectrum  

[Mak the Night]

The Lumicon Deep Sky is a broadband filter rather than a narrowband as the UHC is. It's effects will be more subtle in terms of contrast enhancement. I've tried some broadband filters (Orion Skyglow, Antares ALP, Meade Nebula) and I thought their impact was very modest at most really. Nothing like the difference that a UHC or O-III can make.

OK, thanks for the information. I'm tempted to buy the Astronomik UHC and get the Lumicon UHC later when they become more readily available. 

[John]

I thought the color was from a "red" leak in the NPB's spectrum  

The Lumicon UHC and O-III have, or had, a similar "red leak" I understand. Not that this seems to damage visual performance as far as I can tell.

[Piero]

I think David Knisely main concern about Astronomik's filters are the wider pass band, as he expressed here

It is an interesting thread. Thanks for the link. 

I never tried Lumicons or the DGM NPB, so I cannot say how my Astronomiks compare to those.

They look effective to me. I agree with David about the wide bandwidth of the Astronomik UHC. In my opinion it is a gentle filter, which I do not regret to have though. Interestingly, my findings and approach are pretty much similar to what Jon Isaacs in that thread (and others here in SGL too) say. If the sky is moderately light polluted, I generally prefer my OIII to UHC. Under a darker sky, well, it would be a shame not to have that UHC! The North America seen with UHC was Super!! .. and the Veil with OIII was a "Oh my..!!!"

I experienced other situations where I like the UHC under moderately light polluted skies. This is when I want to see the nebula extension (e.g. M42) or in the summer twilight where to me the OIII was really too much and obscured far too many stars. 

From what I read, in terms of decreasing bandwidth (=> increasing contrast) they go like this: 

Astronomik UHC > DGM NPB > Astronomik OIII > Lumicon OIII 

I believe a DGM NPB shows more contrast than an Astronomik UHC. The latter does not show much to me under a normal sky. However I like it as it is because it allows you to see a fairly rich star field. Personally, I am not sure I would like something filtering more than my Astronomik OIII, because although the contrast might be improved, I still want to see some star. 

So, here we are back to the exit pupil topic..would this opinion change when using eyepieces with larger exit pupils? .. larger than 4mm? ..mm.. dunno if I want to read the answer..! 

To the OP, I think the topic Astronomik/Lumicon/DGM is something similar to the topic Delos/Pentax. The quick answer is that they are all excellent filters and above the majority. You might not even notice the differences or for noticing them you need a very dark sky. If you normally observe from a moderately light polluted sky, I would get an OIII first and an UHC later if you choose Astronomik. Possibly a DGM is all what you need being in the middle of the two Astronomiks.

On the other hand if you are picky, have money/time to try the different brands before landing on your favorite, well, go second-hand!

[Mak the Night]

It is an interesting thread. Thanks for the link. 

I never tried Lumicons or the DGM NPB, so I cannot say how my Astronomiks compare to those.

They look effective to me. I agree with David about the wide bandwidth of the Astronomik UHC. In my opinion it is a gentle filter, which I do not regret to have though. Interestingly, my findings and approach are pretty much similar to what Jon Isaacs in that thread (and others here in SGL too) say. If the sky is moderately light polluted, I generally prefer my OIII to UHC. Under a darker sky, well, it would be a shame not to have that UHC! The North America seen with UHC was Super!! .. and the Veil with OIII was a "Oh my..!!!"

I experienced other situations where I like the UHC under moderately light polluted skies. This is when I want to see the nebula extension (e.g. M42) or in the summer twilight where to me the OIII was really too much and obscured far too many stars. 

From what I read, in terms of decreasing bandwidth (=> increasing contrast) they go like this: 

Astronomik UHC > DGM NPB > Astronomik OIII > Lumicon OIII 

I believe a DGM NPB shows more contrast than an Astronomik UHC. The latter does not show much to me under a normal sky. However I like it as it is because it allows you to see a fairly rich star field. Personally, I am not sure I would like something filtering more than my Astronomik OIII, because although the contrast might be improved, I still want to see some star. 

So, here we are back to the exit pupil topic..would this opinion change when using eyepieces with larger exit pupils? .. larger than 4mm? ..mm.. dunno if I want to read the answer..! 

To the OP, I think the topic Astronomik/Lumicon/DGM is something similar to the topic Delos/Pentax. The quick answer is that they are all excellent filters and above the majority. You might not even notice the differences or for noticing them you need a very dark sky. If you normally observe from a moderately light polluted sky, I would get an OIII first and an UHC later if you choose Astronomik. Possibly a DGM is all what you need being in the middle of the two Astronomiks.

On the other hand if you are picky, have money/time to try the different brands before landing on your favorite, well, go second-hand!

Hmmm ... interesting. Most people have recommended to acquire a narrowband UHC first. I live in the greenbelt so light pollution isn't a huge problem for me. I'll probably get a UHC first, the Lumicon LF3025 (UHC) was the emerging favourite but I may have to wait several weeks for one as they seem difficult to get both sides of the Atlantic from what I've been told. TeleVue are discontinuing some of their filters and I'm not sure where I can get a DGM from easily. I can order an Astronomik 8H0011 (UHC) easily enough though. I'll buy an O-III later still. At least I have a plan now lol. And I don't mind shelling out for a Lumicon and an Astronomik UHC. 

[John]

Once you experience what the UHC can do you will definitely want the O-III and quite quickly too.

The usual recommendation is indeed to go for a UHC first but I'd stick my neck out and say go for a good O-III. It might be all you need ?

[Mak the Night]

Once you experience what the UHC can do you will definitely want the O-III and quite quickly too.

The usual recommendation is indeed to go for a UHC first but I'd stick my neck out and say go for a good O-III. It might be all you need ?

Well, as I'll probably be using any filter I eventually decide to get on my small Mak first, I think the UHC will be more suitable. I do plan on getting a 9.25" SCT early next year however so the O-III would be the logical next step.

[MarsG76]

For UHC, Lumicon is the way to go, I have a few different types of UHC/Nebula filters, Lunicon, Orbinar, Seben.

I first purchased the Orbinar and then Seben filters in my search for the best filter to use on nebulae... Mainly I got them because the price was low, and as they say, you get what you pay for... they do work to a point but I didn't exclaim "WOW" until I started looking through the Lumicon UHC filter... the views and detail I saw on Carina Nebula and Orion has to be seen to be believed, the nebulosity just simply pops out.

The Celestron UHC/LPR filter (apparently the same as Baader UHC-S filter) is only slightly useful on some objects when already in a darkish site.

I can't recommend the Lumicon UHC filter enough, very happy with it.

[Dave In Vermont]

Just a quick look at the Baader UHC-S filter tells me it's a broadband-filter. And not a very good one at that. It has it's uses, but causing one's jaw to drop isn't part of it's repertoire.

A good filter that many overlook is the Orion Ultra-Block. It's quite capable of pulling out fine details, and loosening the jaw. Oddly enough, it's usually offered as a filter for curbing light-pollution. I'm certain I don't understand Orion's marketing-department.

Below is a filter for the enthusiast who claims to have seen them all.

Dave

[Mak the Night]

Just a quick look at the Baader UHC-S filter tells me it's a broadband-filter. And not a very good one at that. It has it's uses, but causing one's jaw to drop isn't part of it's repertoire.

A good filter that many overlook is the Orion Ultra-Block. It's quite capable of pulling out fine details, and loosening the jaw. Oddly enough, it's usually offered as a filter for curbing light-pollution. I'm certain I don't understand Orion's marketing-department.

Below is a filter for the enthusiast who claims to have seen them all.

Dave

Singularity Filter.jpg

I'm looking for a decent cloud filter LOL!

[Mak the Night]

For UHC, Lumicon is the way to go, I have a few different types of UHC/Nebula filters, Lunicon, Orbinar, Seben.

I first purchased the Orbinar and then Seben filters in my search for the best filter to use on nebulae... Mainly I got them because the price was low, and as they say, you get what you pay for... they do work to a point but I didn't exclaim "WOW" until I started looking through the Lumicon UHC filter... the views and detail I saw on Carina Nebula and Orion has to be seen to be believed, the nebulosity just simply pops out.

The Celestron UHC/LPR filter (apparently the same as Baader UHC-S filter) is only slightly useful on some objects when already in a darkish site.

I can't recommend the Lumicon UHC filter enough, very happy with it.

It looks like there is a very good possibility I can get a Lumicon UHC and an O-III filter in about a fortnight. So I'll wait until then.

[Mak the Night]

I use a Lumicon O-III filter and an Omega DGM NBP filter. The latter is a UHC-type filter. Both are pretty much as good as these things get from my experience using them and reports from others.

Filters is one accessory where Tele Vue would not be top of my list to be honest with you. Their quality will be good of course but their narrowband and line filters tend to have rather wide band pass widths than are considered optimum with medium and larger aperture scopes.

A rather good but less expensive UHC type filter that I've owned in the past is the Orion (USA) Ultrablock. The filter guru on the "Cloudynights" forum, David Knisely rates those highly as well.

David Knisely told me that the older Astronomic versions (I had mentioned the Astronomik UHC Deep Sky Filter 8H0011) full width at half maximum bandwidth was a huge 34.2 nm. Yet Astronomik list their ideal filter curve as about 25 nm, which he reckons would work if they actually achieve that.

[YKSE]

From what I read, in terms of decreasing bandwidth (=> increasing contrast) they go like this: 

Astronomik UHC > DGM NPB > Astronomik OIII > Lumicon OIII 

I believe a DGM NPB shows more contrast than an Astronomik UHC. The latter does not show much to me under a normal sky. However I like it as it is because it allows you to see a fairly rich star field. Personally, I am not sure I would like something filtering more than my Astronomik OIII, because although the contrast might be improved, I still want to see some star. 

UHC filters are meant to let through lights in H-beta line (486nm) and OIII lines (496nm and 501nm), while OIII filters are meant only to let through the OIII lines. So the UHC type filters will have wider bandwidth by definition than OIII.

Also by their design purpose, stars will look dimmer in OIII  than in UHC and with more greenish tone (496nm and 501nm are right in the green color wavelength), same is true that a filter with narrower passband wiill show dimmer stars and less color variations, that's just simple nature of narrower passband.

The purpose of these filters are meant to enhance the contrast of nebulas with lights mainly in these wavelengths, some nebulas have very strong light in OIII lines  like the Veil, an OIII will surely be better than UHC, while others have strong H-beta line, like Cave nebula or Cocoon, then an UHC will be the right filter.

Edit:

Here a picture of color spectrum copied from Wiki: