13 replies to this topic

[Whiteduckwagglinginspace]

Hi all,

I don't trust the Skywatcher UHC filter (don't get any effect on nebulae with this filter, except a green colour) so I decided to order the Astronomik UHC filter. According to threads on CN, a very good UHC filter.

But now there seems to be 2 different Astronomik UHC-filters: 
- Filter with blue/green glass - Astronomik UHC-E (65 euro)
- Filter with purple glass - Astronomik UHC (99 euro)

Which one to get...? 

[davidgmd]

I use the more expensive UHC version. It has a narrower bandwidth and will increase the apparent contrast more than the UHC-E (economy) version.

  
The other thing to consider, if you use 2” eyepieces in longer FLs for viewing emission nebulae, is to get the 2” version. Costs more, but can be used with both 1.25” and 2” eyepieces by screwing it into the diagonal.

[CrazyPanda]

UHC-E is more of a broadband filter than narrowband (something like 48nm of bandwidth instead of 24-26nm). The name is misleading. Stick to the regular UHC.

Edited by CrazyPanda, 24 February 2025 - 12:26 PM.

[Mike G.]

here's the spectral curves:

 

 

 

I like the UHC in my bigger scopes, but for my 100mm binos I use the UHC-E.  The more narrow UHC tends to darken too much to my liking with smaller apertures.  Just my personal preference.

[Whiteduckwagglinginspace]

All great answers. Thank you (all) very much! It's obvious I have to get the one with the purple glass.. 
 

[Starman1]

Hi all,

I don't trust the Skywatcher UHC filter (don't get any effect on nebulae with this filter, except a green colour) so I decided to order the Astronomik UHC filter. According to threads on CN, a very good UHC filter.

But now there seems to be 2 different Astronomik UHC-filters: 
- Filter with blue/green glass - Astronomik UHC-E (65 euro)
- Filter with purple glass - Astronomik UHC (99 euro)

Which one to get...? 

The inexpensive UHC-E has a 49-50nm bandwidth and it about the same as the Svbony UHC.

So the only one to look at is the UHC proper, as it's bandwidth is in the 26nm range and will yield a dramatic improvement in contrast.

 

since the filter will be used at powers no higher than 12x/inch, if your low powers are 2" eyepieces, get the 2" filter.

Edited by Starman1, 25 February 2025 - 05:19 PM.

[Apnee44]

You will not be disappointed with the Astronomik UHC filter. It is not cheap, but very efficient. You can try to get one from used market (about 40/50 euros).
Clear sky

[Starman1]

You will not be disappointed with the Astronomik UHC filter. It is not cheap, but very efficient. You can try to get one from used market (about 40/50 euros).
Clear sky

Careful with a used purchase, though.

Before ~2016, Astronomik UHC filters had a wider bandwidth.

You want a more current sample.

[Whiteduckwagglinginspace]

Careful with a used purchase, though.

Before ~2016, Astronomik UHC filters had a wider bandwidth.

You want a more current sample.

So, I bought a new one for 99 euro.
 
Don't know how long these kind of things can stay on the shelf, before selling. But I assume I have a new (after 2016) one. 

Do you know how you can see the difference between the old / new one? (added some pictures)

Hope I got the right one, because it was not easy to get one. Customs in Norway are terrible!


 

[Starman1]

So, I bought a new one for 99 euro.

Don't know how long these kind of things can stay on the shelf, before selling. But I assume I have a new (after 2016) one.

Do you know how you can see the difference between the old / new one? (added some pictures)

Hope I got the right one, because it was not easy to get one. Customs in Norway are terrible!

If you ask Astronomik, they can tell you all about the filter from the serial number. P.S. their stickers yellow after a couple years and yours are pure white.

Edited by Starman1, 13 March 2025 - 03:43 PM.

[Apnee44]

So, I bought a new one for 99 euro.

Don't know how long these kind of things can stay on the shelf, before selling. But I assume I have a new (after 2016) one.

Do you know how you can see the difference between the old / new one? (added some pictures)

Hope I got the right one, because it was not easy to get one. Customs in Norway are terrible!

I got new and old ones(Profi type, which cut IR), I could not see any difference. You will really enjoy it 🙂. Next will be the OIII

[Whiteduckwagglinginspace]

After purchasing the Astronomik UHC filter, I compared the Astronimik with the SkyWatcher UHC filter.

Astronomik UHC filter = 24 NM bandwidth.

Skywatcher UHC filter = 28 NM bandwidth.

Both bandwidth should be good.

In practice: (using both filters on emission nebulae and planetary nebulae)
- The Astronomik makes several emission nebulae visible, while they're not visible without this filter.
- The Astronomik makes planetary nebulae much more clearly, compared with the naked eye.
- The Skywatcher UHC filter makes no differences, compared with my own eyes. Planetary nebulae looks different through the filter, but are not clearer.

Maybe the Skywatcher filter will do better on other nebulae, but so far this filter does not work. 
If 28 NM bandwidth should work on nebulae, I'm in a doubt if this filter really is 28 NM bandwidth.   
 

[davidgmd]

Makes you wonder if the Skywatcher filter's bandwidth is significantly greater than the stated 28 nm. Or if its peak transmission misses one or more of the Ha and OIII lines. 

[Apnee44]

I got one Skywatcher in the past, it was really not same level as the Astronomik. I really understood the use of an UHC filter by using the Astronomik 🙂. I tried as well one Lumicon (old version), it was really good as well.