22 replies to this topic

[plofstof]

I am new to fast optics like Hyperstar.  Recently got one for my EdgeHD 11 and keen to try it out.  I love NB imaging and was hoping to try it on the Hyperstar...

 

But as always in this hobby, I learned that things are a bit more complicated than just using my existing Antlia 3nm SHO filters

I watched this video from Cuiv and read the excellent article linked in it, and I now get the problem with blue shift and all that.

 

My EdgeHD11 will image at f/1.9 using Hyperstar.  Which is super fast.

 

A friend of mine talked to a vendor who recommend Astronomik MaxFR filters like this one or this one which is ostensibly rated for f/1.7  

Boy, are they expensive.  And I thought I was done investing in filters

 

Do any brands other than Astronomik offer high-speed NB filters?

 

As far as I can tell I need to buy the Astronomik MaxFR 12nm filters as they are ostensibly rated all the way up to f/1.7

 

Is there any other brand that I can check out?  Or any other recommendations about NB using a Hyperstar.

 

 

 

 

[afd33]

Chroma also has ones that in Agena Astro's description say are optimized from F2.8 to F3.6. Linked is the 36mm set. https://agenaastro.c...-unmounted.html

[plofstof]

Chroma also has ones that in Agena Astro's description say are optimized from F2.8 to F3.6. Linked is the 36mm set. https://agenaastro.c...-unmounted.html

Thanks.  My Hyperstar will apparently take me to F1.9 so I'm not sure how important it is to get a filters that are rated up to that kind of speed.  So far the only ones I can see are Astronomik MaxFR 12nm (not 6nm)

[happylimpet]

Thanks.  My Hyperstar will apparently take me to F1.9 so I'm not sure how important it is to get a filters that are rated up to that kind of speed.  So far the only ones I can see are Astronomik MaxFR 12nm (not 6nm)

If you get filters that work up to (for example) f3, then the scope will effectively be stopped down to f3 for that emission line. i.e. you're wasting A LOT of light. Another way round is just to get wider filters - its only expensive to get narrow ones which are also suitable for fast fratios.

[dac4215]

If you get filters that work up to (for example) f3, then the scope will effectively be stopped down to f3 for that emission line. i.e. you're wasting A LOT of light. Another way round is just to get wider filters - its only expensive to get narrow ones which are also suitable for fast fratios.

How wide does the filter need to be? Would an L-extreme be wide enough, or would you need wider like a L-enhance?

[bobzeq25]

I am new to fast optics like Hyperstar.  Recently got one for my EdgeHD 11 and keen to try it out.  I love NB imaging and was hoping to try it on the Hyperstar...
 
But as always in this hobby, I learned that things are a bit more complicated than just using my existing Antlia 3nm SHO filters
I watched this video from Cuiv and read the excellent article linked in it, and I now get the problem with blue shift and all that.
 
My EdgeHD11 will image at f/1.9 using Hyperstar.  Which is super fast.
 
A friend of mine talked to a vendor who recommend Astronomik MaxFR filters like this one or this one which is ostensibly rated for f/1.7  
Boy, are they expensive.  And I thought I was done investing in filters
 
Do any brands other than Astronomik offer high-speed NB filters?
 
As far as I can tell I need to buy the Astronomik MaxFR 12nm filters as they are ostensibly rated all the way up to f/1.7
 
Is there any other brand that I can check out?  Or any other recommendations about NB using a Hyperstar.

C8 RASA here. F2.

The 6nm MaxFR works great for me. You lose a bit of signal compared to the 12, but you lose MORE light pollution, and dial back the stars more, so it's a win. I got it because the camera has low dark current, and I wanted to use it in Bortle 7. You think the 12 is expensive? Example below, click on it for a good version and details. Got the dim outer area in Bortle 7. Most people don't get it, anywhere. I only have Ha and O(III). Few targets have much S(II), so it wasn't worth it to me.

This is not a cheap hobby, nor is it easy. Use a big fast scope, and it gets more expensive and harder. Yes, there are other high speed filters. But no magic cheap ones that work well.

Sign in an automotive speed shop. "Speed costs money. How fast do you want to go?" <smile>

The 12nm should work OK for you. But the 6 will work better. There are good reasons it costs more.

Edited by bobzeq25, 18 June 2025 - 10:10 AM.

[bobzeq25]

How wide does the filter need to be? Would an L-extreme be wide enough, or would you need wider like a L-enhance?

None of your optics are fast enough to worry about it. But, if you get a fast scope, using a filter designed for high speed optics is better. With a color camera, I use the Hutech IDAS NBZ. Example below, click on it...

[JGLeigh]

The 6nm MaxFR works great for me. You lose a bit of signal compared to the 12, but you lose MORE light pollution, and dial back the stars more, so it's a win.

Same here, I compared my SVB220 7nm filter against an IDAS 12nm filter on my Hyperstar/C6 rig. The 12nm gave more signal, but proportionately more noise. Not a huge difference, but noticeable, and every little bit pf performance helps.

[dac4215]

None of your optics are fast enough to worry about it. But, if you get a fast scope, using a filter designed for high speed optics is better. With a color camera, I use the Hutech IDAS NBZ. Example below, click on it...

Thanks. I have been thinking about getting a hyperstar for the c6, but having to spend more on new filters has me thinking twice.

[bobzeq25]

Thanks. I have been thinking about getting a hyperstar for the c6, but having to spend more on new filters has me thinking twice.

Something else to consider. The tiny depth of field means the optical train needs to be aligned perfectly, or parts of the frame will be out of focus. Took me weeks to get that under control.

[plofstof]

Thanks, these are very useful responses to my question.  Which leads me to two more questions.
 
First, considering this information that Astronomik provides on their website:

The MaxFR coating is designed to work perfectly with very fast optical systems.

• For 12nm filters with MaxFR coating, this means unlimited usability from f/1.7 to f/8 and approximately 85% of the maximum transmission at a f/1.4.
• For 6nm filters with MaxFR coating, this means unlimited usability from f/2.2 to f/8 and approximately 90% of the maximum transmission at a f/2.

Filters for even faster optics are available upon request.

 

 
Putting questions of price aside, and considering that the EdgeHD 11 Hyperstar is specced as f/1.9.  It seems the tradeoff now:

• with 6nm I will have the benefit of less light pollution
• at the cost of I guess ~10-15% of signal (the say "approximatley 90% at f/2") 

According to bobzeq25 this tradeoff is a win:

 

You lose a bit of signal compared to the 12, but you lose MORE light pollution, and dial back the stars more, so it's a win.

Question 1:
Does everyone agree with bobzeq25 here that the tradeoff is worth it?  I guess my reluctance to go to 6nm stems from the fact that I was so excited about speed I don't want to cut back on any signal.  For more background, I do a lot of my imagining in under bortle 6 skies using the ASI2600MM which has minimal dark current. 

Question 2:
Is Astronomik the only filter manufacturer that provides NB filters specifically for fast optics?  (Their MaxFR range in particular).  No one else?

[Fegato]

Q1 - I think there's a sliding scale here depending on your light pollution. In dark skies, the gains of narrower bands are there, but smaller.

 

Q2 Baader have a set of narrow filters for F/2.3 or faster. These are 3.5nm (Ha) and 4nm for OIII and SII. I don't have them, but some people have certainly had good results with them, although I'd do some research on that. Probably more expensive than the Astronomik 12nm. 

[plofstof]

Q1 - I think there's a sliding scale here depending on your light pollution. In dark skies, the gains of narrower bands are there, but smaller.

 

Q2 Baader have a set of narrow filters for F/2.3 or faster. These are 3.5nm (Ha) and 4nm for OIII and SII. I don't have them, but some people have certainly had good results with them, although I'd do some research on that. Probably more expensive than the Astronomik 12nm. 

OK I had a look, and this looks like a strong contender from Baader.

[Fegato]

OK I had a look, and this looks like a strong contender from Baader.

Yes they're the ones. Very positive feedback on the Baader site at least...

[plofstof]

Yes they're the ones. Very positive feedback on the Baader site at least...

I did some more searching and found this thread which seems quite negative about the Baader filters... 

 

Several reports on QA issues, and halos.  Perhaps it is Astronomik then... 

[Kerste]

That is old news and the reason why Baader got more specific with their filter selector:
https://www.baader-p...r-cmos-filters/

[plofstof]

That is old news and the reason why Baader got more specific with their filter selector:
https://www.baader-p...r-cmos-filters/

I'm glad to hear that this is old news...

 

I went through the filter selector which recommends the f/2 ultra-highspeed set for my situation.  By the way, why are they called CMOS optimized?  Does that matter?  I have a CCD camera (2600MM), like most other people these days.

 

I guess it comes down to Baader's ultra-highspeed 3.5nm/4nm set (above) vs Astronomik's MaxFR 6nm vs Astronomik's MaxFR 12nm.

 

• Baader shows the narrowest bands on paper and talks about "less than f/2.3"
• Astronomik rates the 12nm as giving 100% signal all the way down to f/1.7 
• But also says the 6nm will give around 85-90% of signal at f/2 (I'm going to be at f/1.9)

 

I'm sure if I ask for subjective opinions on Baader vs Astronomik I will get as many different views as I get responses...? 

But I'm keen to hear any views out there, disregarding price.  I never know whether more expensive is necessarily better.  

Edited by plofstof, 19 June 2025 - 06:12 AM.

[Fegato]

I'm glad to hear that this is old news...

 

I went through the filter selector which recommends the f/2 ultra-highspeed set for my situation.  By the way, why are they called CMOS optimized?  Does that matter?  I have a CCD camera (2600MM), like most other people these days.

 

I guess it comes down to Baader's ultra-highspeed 3.5nm/4nm set (above) vs Astronomik's MaxFR 6nm vs Astronomik's MaxFR 12nm.

 

• Baader shows the narrowest bands on paper and talks about "less than f/2.3"
• Astronomik rates the 12nm as giving 100% signal all the way down to f/1.7 
• But also says the 6nm will give around 85-90% of signal at f/2 (I'm going to be at f/1.9)

 

I'm sure if I ask for subjective opinions on Baader vs Astronomik I will get as many different views as I get responses...? 

But I'm keen to hear any views out there, disregarding price.  I never know whether more expensive is necessarily better.  

2600MM is a CMOS camera...   modern astro cams are CMOS these days, which have largely replaced the older CCD technology. No real difference in the actual pixels, just the way the data is read I think.

 

As for "CMOS optimised"...  I suspect that's marketing blurb, but I stand ready to be corrected!

[MichaelACG]

...  By the way, why are they called CMOS optimized?  Does that matter?  I have a CCD camera (2600MM), like most other people these days.

Like most others, you have a CMOS camera. CMOS has (for imaging) nearly completely replaced CCD. 
 

CMOS sensors have a slightly different spectral response (i.e. sensibility) than CCD, therefore I believe Baader (high end offering) that they have optimized their filters for CMOS.

[plofstof]

Like most others, you have a CMOS camera. CMOS has (for imaging) nearly completely replaced CCD. 
 

CMOS sensors have a slightly different spectral response (i.e. sensibility) than CCD, therefore I believe Baader (high end offering) that they have optimized their filters for CMOS.

Doh!  That was embarrassing.  I always end up confusing the two.

[calypsob]

fast filters have to be tuned to pass the specd bandwidth requirement for fast apertures and they need to be of appropriate thickens and have correct coatings to avoid generating halos around bright stars. 

[bobzeq25]

I guess it comes down to Baader's ultra-highspeed 3.5nm/4nm set (above) vs Astronomik's MaxFR 6nm vs Astronomik's MaxFR 12nm.

Three good choices. I happen to like Astronomik, and the argument for image quality with the 6nm was convincing. But they are way more expensive than the 12, which would work.

I'm not rich, but I put a lot of my precious time into imaging, and wanted to make the most of it.

[bobzeq25]

I did some more searching and found this thread which seems quite negative about the Baader filters... 
 
Several reports on QA issues, and halos.  Perhaps it is Astronomik then... 

It's the safest choice. Astronomiks had some issues with halos several years ago, you'll find that complaint way back then. More recently complaints about Astronomik filters have been few and far between.

Except for the prices. <smile>

Edited by bobzeq25, 19 June 2025 - 05:36 PM.