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Askar Super-Duo-Narrowband D2 vs Askar Duo-Narrowband D2 Filter

Equipment Filters Duo-Narrowband
10 replies•187 views
Georg N. Nyman avatar
Georg N. Nyman avatar
Hi everyone,

Some pictures of these filters show the (maybe) same filter - one says Super-Duo-Narrowband D2 and another image from another vendors says Duo-Narrowband D2.
Is there a difference - one of the German vendors told me no, they are the same as long as it state D and not C….
D series are narrower than C, that is clear, but what is your opinion or experience regarding that little word "Super" in front of the entire name of the filter?

Thanks and CS
Georg
Tony Gondola avatar
Tony Gondola avatar
Marketing? Are the bandpass plots the same?
Georg N. Nyman avatar
Georg N. Nyman avatar
Tony Gondola:
Marketing? Are the bandpass plots the same?

The bandpass plots look identical but for the "Super" it is often stated "halo-free".. I just do not know
Mark Fox avatar
Mark Fox avatar
At one point, Askar also made a "super narrowband" G1 (HO) and G2 (SO) set.  I believe they were spec'ed at 3nm.  Maybe a vendor isn't providing an accurate description?

Edit:  Don't worry about the G series.  What it's all about are the specs on bandwidth.  High Point and Agena show good specs, which are in the 6nm to 7nm range for each line on the D series.  Ignore those marketing terms like 'super'…. super, relative to what??? 

I think Askar has eliminated the G series and only has C and D, with D being tighter bandwidth than C.  So maybe they've migrated the 'super' descriptions from the G series to the D series.
Helpful
jmdl101 avatar
jmdl101 avatar
From personal experience, the D series is not halo free, but it seems to be luck of the draw. I'm pretty sure they are listed as not able to be returned for halos, at least on some sellers.
andrea tasselli avatar
andrea tasselli avatar
Can't see any major difference between the two and my copy is in fact "halo-free", to a considerable degree. Below is a 1 minute integration with Alpha Orionis off center to test what glare do I get at f/4. 

jmdl101 avatar
jmdl101 avatar
andrea tasselli:
Can't see any major difference between the two and my copy is in fact "halo-free", to a considerable degree. Below is a 1 minute integration with Alpha Orionis off center to test what glare do I get at f/4. 




​​​​​​Is this a non debayered color image? There definitely looks like a halo around the star, somewhat hidden in the brightness, but definitely defined circle. 

My experience with the D1 and D2 for comparison, including a relatively dim star near the California Nebula. 

Mine were from when they first released the filters also so they very well could have improved the performance since then. 
andrea tasselli avatar
andrea tasselli avatar
No halo in my image, sorry, just a off-center flare (which undoubtedly can be also annoying). Here is the debayered and stretched but otherwise unprocessed image. I can't see any hint of an halo, just diffraction effects from the spider system in my newt, whose vanes are circular. And, yes, my filter is a recent copy, just over a year old.
jmdl101 avatar
jmdl101 avatar
andrea tasselli (andreatax)No halo in my image, sorry, just a off-center flare (which undoubtedly can be also annoying). Here is the debayered and stretched but otherwise unprocessed image. I can't see any hint of an halo, just diffraction effects from the spider system in my newt, whose vanes are circular. And, yes, my filter is a recent copy, just over a year old.


I'm referring to that blue ring (not the reflection flare) in your image, now that it's color it confirms what I thought, of course it might just be an artifact or from the circular spider also, but looks like the same blue issues I had two years ago. They are still pretty good filters, and one of the only manufacturers that make the Oiii/Sii version. They are great for doing SHO images with a OSC camera. I just bought an Antila 5nm Ha/Oiii to see how it does compared to my old NBZ that I sold a while back. The NBZ was completely halo free but a little wider than I wanted. 

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jmdl101 avatar
jmdl101 avatar
Looks like Agenaastro also got rid of that non-returnable for halos statement, so maybe the improvements have made them much better. I am glad to see the true bandpass information, they used to just advertise them as 6nm, which they were clearly wider than that. The real specs are now listed in the description so that's great.
andrea tasselli avatar
andrea tasselli avatar
I'm referring to that blue ring (not the reflection flare) in your image, now that it's color it confirms what I thought, of course it might just be an artifact or from the circular spider also, but looks like the same blue issues I had two years ago


*Nope, that's how diffraction plays with colors and a circular strut. A halo is an image of the exit pupil of the system superimposed to the primary star's image.