Orion Ultrablock filter - issues

[Siegfried1969]

Hello all,

I need your advise about my Orion Ultrablock filter I have bought years ago. This filter is a 'Made in Korea' one and thus the newer version. My telescope is a small 110 mm Newtonian TAL-1 at f/7.3.

 Now, at several occasions I have tried this filter on the Orion nebula and the documentation says I should see "a very dark sky background and somewhat dimmer but high contrast image". Actually that is not what I am seeing at all. Everything gets indeed much darker but the nebula itself almost disappeared and I see actually much more details in the nebula without this filter. Only what left of the orion nebula with this filter is a very faint patch of gray, much smaller than without filter and not details at all. This is not what people usually say about this class of filters. Everybody is speaking about huge improvements in contrast but I do not see that. My observing site is at home which is a bortle 5. Now I am thinking of some reasons why that can be:

• Telescope is too small
• Filter has a too low transmission for the Hbeta and O3 lines or transmits the wrong spectral lines and is somehow faulty
• That is just the way this filter works

Anyway, this filter is clearly not delivering the expected results and I am thinking on how to remediate that:

• Or buying another UHC filter from another brand like Astronomik or the DGM NPB, Televue bandmate or whatever in the hope this gives a better result
• Or buying a broader filter like the baader UHC-S or Astronomik UHC-E
• Or buying both if there is not too much overlap between these filters and if each of them would have their use

I would like to know if my experience with this Orion Ultrablock filter is normal behaviour and if no, by what I should replace it.

 
Thanks a lot !

[Stu]

Can I ask what magnification you are using? With small scopes, you need to keep the exit pupil size up with these filters or the view does get too dark. Somewhere around 4mm and above would be good which would mean around a 30mm eyepiece and x26 ish. Too much power and yes, it will get dark.

[Guest]

There are a lot of factors going on when it comes to how well a filter works, up to and including the kind of lighting around you down to the kind of scope you have.   I will agree with Stu on this one.  You have a smallish reflector there that can only gather so much light, now you are throwing a fliter in there that cuts it down more.   I have that filter and use it once in a while.  Another option that might work better is a OIII filter.  I will provide a link to a filter shoot out that was done a while ago.  Maybe you will find some useful info in it.

https://www.prairieastronomyclub.org/filter-performance-comparisons-for-some-common-nebulae/

 

 

 

 

[jetstream]

3 hours ago, Siegfried1969 said:

I would like to know if my experience with this Orion Ultrablock filter is normal behaviour and if no, by what I should replace it.

I dont mean to be rude here. I had an Orion Ultrablock years ago and had the same experience. It tainted my view of filters to the point that I thought all UHC types dont work very well. I was new at astronomy then.

I bought a top quality (tight, high transmission) UHC and the difference was staggering.

I threw my Orion Ultrablock in the garbage and didnt look back.

Gerry

[Siegfried1969]

3 hours ago, Stu said:

Can I ask what magnification you are using? With small scopes, you need to keep the exit pupil size up with these filters or the view does get too dark. Somewhere around 4mm and above would be good which would mean around a 30mm eyepiece and x26 ish. Too much power and yes, it will get dark.

I used my lowest eyepiece which is a 25 mm Vixen SLV. That is a magnification of 32 x and an exit pupil of 3,4 mm. I did not try higher magnifications as 32 x is already so dreadful. I can say it simply like that: If you would let 100 people compare the view of M42 with and without the filter, nobody would choose the view with the filter.

[Siegfried1969]

50 minutes ago, Mike Q said:

There are a lot of factors going on when it comes to how well a filter works, up to and including the kind of lighting around you down to the kind of scope you have.   I will agree with Stu on this one.  You have a smallish reflector there that can only gather so much light, now you are throwing a fliter in there that cuts it down more.   I have that filter and use it once in a while.  Another option that might work better is a OIII filter.  I will provide a link to a filter shoot out that was done a while ago.  Maybe you will find some useful info in it.

https://www.prairieastronomyclub.org/filter-performance-comparisons-for-some-common-nebulae/

 

 

 

 

Thanks a lot Mike ! I still have to read it more in detail but that looks a very interesting review. But what they are saying is that an OIII filter can also be used on smaller telescopes, what you are suggesting as well. I thought exactly the opposite... going broader instead like baader UHC-S or Astronomik UHC-E.

[jetstream]

3 minutes ago, Siegfried1969 said:

exit pupil of 3,4 mm

Need around 5mm IMHO, plus or minus a bit

[Siegfried1969]

12 minutes ago, jetstream said:

I bought a top quality (tight, high transmission) UHC and the difference was staggering.

What exactly did you buy if I may ask ?

[Guest]

3 minutes ago, Siegfried1969 said:

Thanks a lot Mike ! I still have to read it more in detail but that looks a very interesting review. But what they are saying is that an OIII filter can also be used on smaller telescopes, what you are suggesting as well. I thought exactly the opposite... going broader instead like baader UHC-S or Astronomik UHC-E.

I am still learning this too.  So all i can say is what I have seen here under my conditions.  For the Orion Nebula in my 10 inch.... No filters needed.  One night i will try both the OIII and UHC on it.  Where i have used them is on the southern sky nebula like the eagle, triffid and lagoon.  Some nights the OIII is better and some nights the UHC seems better.  So all i will suggest is get one and give it a go and see what happens.  

[jetstream]

1 minute ago, Siegfried1969 said:

What exactly did you buy if I may ask ?

I have numerous top filters now, including an older but great Lumicon UHC and also the NEW Televue Nebustar.

Forget about Lumicon now.

Buy the latest Astronomik tight UHC or the Televue (made by Astronomik).  Seriously, a bunch of us went through piles of test results, specs etc and now these are the 2 top choices IMHO. Same goes for 0III.

The older Astronomiks were good but a bit wide- I have one of those too- but they tightened up the newest ones and are excellent.

 

[NGC 1502]

It’s a mystery to me why an Orion UltraBlock should not be excellent.  The one I had for years gave wonderful views when used on the right object.  This was even with very modest apertures like my 70mm TV Pronto, although that was under an excellent sky at Kelling Heath in Norfolk.

The only issue I had with the UltraBlock was thread compatibility.

I replaced it when a friend was selling off equipment and I bought his Lumicon UHC.  Direct comparison did show the Lumicon was marginally better, depending on the object in view. And zero compatibility issues, it fits any eyepiece or accessory I’ve tried it on.

[PeterC65]

7 minutes ago, jetstream said:

Buy the latest Astronomik tight UHC or the Televue (made by Astronomik).

I've been waiting for the new Astronomik UHC filter to appear (with IR cut). Have you seen it for sale anywhere yet?

 

[jetstream]

1 minute ago, PeterC65 said:

I've been waiting for the new Astronomik UHC filter to appear (with IR cut). Have you seen it for sale anywhere yet?

 

No, I'm not aware of this one- I havn' checked the filters out for a bit. I think Televues spec cut off the high end there though. Not sure if this matters- my old Lumicon is superb with out this and my new Televue is also superb,if I had to pick though it would be the Televue, but we are splitting extremely small hairs.

[jetstream]

Heres the difference

 

[jetstream]

[Siegfried1969]

21 minutes ago, NGC 1502 said:

It’s a mystery to me why an Orion UltraBlock should not be excellent.

Well to me as well. And this filter was not cheap. I bought it when I was living in Singapore and I paid 298 SGD for the 1,25". On teleskop-service, the 2" Orion ultrablock cost more than the Astronomik UHC 2". So it is by no means a budget filter. The main difference what I can see is that the transmission is around 10 % lower and everything in the red is blocked.

Any opinions on the Baader UHC-S ? 

 

[jetstream]

13 minutes ago, Siegfried1969 said:

Any opinions on the Baader UHC-S ? 

It only passes one spectral line in OIII. Some of  dob mob had one.

From Reiner Vogel

"a 2" OIII by Baader, which is in particular with fainter OIII objects clearly inferior to the Lumicon OIII and considerably cuts the fainter of the OIII lines at 496nm."

I''ll try to find the tests, its been a while

[jetstream]

Sorry that was the OIII, heres the Badder UHC tests- its wide

[jetstream]

vs the old, top lumicon

[jetstream]

https://www.astroamateur.de/filter/uhc.html

[Siegfried1969]

6 minutes ago, jetstream said:

https://www.astroamateur.de/filter/uhc.html

That is a very interesting site ! Thanks a lot ! I assume these are actual test results and not the generic graphs. Baader UHC-S and Astronomik UHC-E are very similar. 

[jetstream]

2 minutes ago, Siegfried1969 said:

That is a very interesting site ! Thanks a lot ! I assume these are actual test results and not the generic graphs. Baader UHC-S and Astronomik UHC-E are very similar. 

Yes, but the new Astronomik is much tighter as are their new OIII- they are not the same filters bandwidth wise. Look at the old Lumicon bandwith and transmission- this is what youre looking for.

The new Astronomik and Televue Bandmate II are the best of the best now. These 2 brands are the only ones I would buy currently.

BTW, when Lumicon transitioned to new owners I purchased a 2" Hb... it resides in the same place as the UltraBlock... I dont know how Lumicon is today, but Ive spent enough cash on the filters to know that a sure thing is needed.

[Guest]

2 hours ago, NGC 1502 said:

It’s a mystery to me why an Orion UltraBlock should not be excellent.  The one I had for years gave wonderful views when used on the right object.  This was even with very modest apertures like my 70mm TV Pronto, although that was under an excellent sky at Kelling Heath in Norfolk.

The only issue I had with the UltraBlock was thread compatibility.

I replaced it when a friend was selling off equipment and I bought his Lumicon UHC.  Direct comparison did show the Lumicon was marginally better, depending on the object in view. And zero compatibility issues, it fits any eyepiece or accessory I’ve tried it on.

I see people saying Orion filters only fit Orion eyepieces.  They seem to fit my Explore Scientific eyepieces very well.  

Edited February 12, 2023 by Mike Q

[PeterC65]

1 hour ago, jetstream said:

No, I'm not aware of this one- I havn' checked the filters out for a bit. I think Televues spec cut off the high end there though. Not sure if this matters- my old Lumicon is superb with out this and my new Televue is also superb,if I had to pick though it would be the Televue, but we are splitting extremely small hairs.

OK. I think it is yet to be released.

 

[Siegfried1969]

I got an update on this story. I bought an Astronomik UHC from Teleskop Service and received it last week. Yesterday night I tried it on M42. I can say that this was a whole different experience and much more in line with what I expected from an UHC filter.

I first looked at M42 without filter for a while with a 3,5 mm exit pupil. Then I added the filter and the sight was really impressive. The nebula was suddenly 2 to 3 times as big and immediately started to see the clear and darker regions in the nebula complex. With the Orion Ultrablock, the size was only half of the size in the view without filter. At the end I got decent results with the Orion Ultrablock but had to be real dark adapted which is not easy when observing from my home.

So without making generalizations, All I can say that this particular sample of the Astronomik UHC is far superior than my sample of the Orion Ultrablock. I will keep both and test them on some more objects. Maybe there will be objects where the Ultrablock will have the edge.