RGB Filter question - Baader vs Astronomik DeepSky

Lasastard
15 Sep, 2017 09:48
Hi,

first off, I am almost certain this must have been asked before, but wasn't able to dig up a thread. Apologies!

I am about to pull the trigger on a QHY163m + QHY 7-slot filter wheel in combination with my 4" TS Triplet APO and 3" Reducer/flattener.

I have now to decide which LRGB Filter(s) to buy and am torn between:

Baader LRGB and Astronomik DeepSky RGB + L2

I did a bunch of searching on the interwebs, but there seems to be no clear recommendation one way or the other. Astronomik had somewhat mixed reviews in the past (2011ish), but seems to have improved a lot in the past year or two. Baader on the other hand has consistently produced good filters, but are not marketed quite as "top notch high end" as the DeepSky Set from Astronomik.

The way I see it:

Baader seems cheaper and narrow band filters in particular are a lot cheaper than the Astronomik ones (Baader 7nm Ha = 150€, Astronomik Ha 6nm = 280€). But they are twice as thick (i.e. add around 1mm to my working distances after the reducer) and may or may not produce halos around brighter stars. Baader filters have also been reported to not be fully parfocal, which would be annoying of course when running exposure series.

Astronomik are more expensive, but marketed as reflection free, super resistant and are thin enough to not matter as far as my working distances are concerned (not an issue one way or the other, really). Astronimik filters are also said to be fully parfocal.

So..what do do?! Any experiences that could help me decide? The price difference for the LRGB Set really isn't the issue, but it starts adding up when considering NB filters (which I want from the same manufacturers  for focusing purposes). Leaning towards Astronomik - assuming the criticism of Baader filters is in fact warranted. But wouldn't mind saving a few hundred bucks if the Baader filters would give me similar results.

CS,
Marc
Die_Launische_Diva
15 Sep, 2017 11:20
Hello Marc,

I have no experience on the subject but maybe this LRGB filter test be helpful.

HTH and Clear Skies!
Edited 15 Sep, 2017 11:20
Lasastard
15 Sep, 2017 11:36
Thanks, I also stumbled across Tommy's little review/test. His images seem to support the idea that Astronomik has a bit of an edge over Baader (stars look a bit tighter to me), but that both brands will produce some degree of artifacts; this seems unavoidable.
Caspar
17 Sep, 2017 17:42
Marc, take a look at my Pictures, i only  take Photographs with Astronomik- Filters. CS Caspar
TareqPhoto
06 Oct, 2017 08:34
Marc, did you buy or decide on which RGB filters yet?

I have an option for you if you still look for one.
Lasastard
06 Oct, 2017 08:42
Hi,

yes I went with the Baader ones but haven't had time to test them yet. i've been told that the halo and reflection issues are very much dependent on the imaging system - no way of telling beforehand how it will work out. Some people have had zero problems with Baader filters, others did - sometimes with only one color channel, or a particular NB filter. But the same is true for Astronomik.

So I am hoping that I won't run into problems smile Will update this thread once I had the chance to take a few subs..

/M
TareqPhoto
06 Oct, 2017 09:38
Great, congratulations then!  smile
Lasastard
19 Dec, 2017 10:35
Maybe as a small update since I haven't had too much time to test them yet (awful streak of bad weather here):

10mins Ha exposures - little to no problem (minor artefact around very bright stars, see my gallery for example)
LRGB Galaxy imaging - no issues at all, looking good (nothing to show yet, need more integration time)
LRGB imaging of bright stars - well, this is where we get into some problems. Tried the Pleijades the other night and am getting very noticable reflections on the blue channel. This is likely an issue with my imaging system overall and not specifically with the filters (triplet apo + multi-lens flattener/reducer). Some things I can try, like flipping the B filter over (recommended by Baader in such instances). Or stay clear of very bight stars (less ideal, but of course an option, plenty of objects left still)
TareqPhoto
22 Dec, 2017 18:02
Congratulations!

I tested mine and sounds it is doing fine, i am talking about LRGB only, i don't have NB set yet, and my Astrodon Ha 5nm 1.25" is definitely a top quality no doubt.
Lasastard
26 Mar, 2018 09:38
Here are a couple of things I have learned in the meantime:

I had to fashion small black card board rings (width about 1.5mm)  to put on top of the filter to cover the edge of the glass. It seems that the multi-coating does not stretch all the way to the edge, which can produce unwanted reflections inside the filter when taking flats. Cost me grant total of 15 bucks, but debugging the issue resulted in more than a few grey hairs.

I have since added the Baader UHC-S filter to deal with skyglow in my area. The background really benefits from this and the filter produce stighter stars than the normal L filter, but it also results in "nasty" halos around even moderately bright stars.
bobzeq25
27 Mar, 2018 03:22
Marc
Here are a couple of things I have learned in the meantime:I had to fashion small black card board rings (width about 1.5mm)  to put on top of the filter to cover the edge of the glass. It seems that the multi-coating does not stretch all the way to the edge, which can produce unwanted reflections inside the filter when taking flats. Cost me grant total of 15 bucks, but debugging the issue resulted in more than a few grey hairs.

I have since added the Baader UHC-S filter to deal with skyglow in my area. The background really benefits from this and the filter produce stighter stars than the normal L filter, but it also results in "nasty" halos around even moderately bright stars.
I use the milder Baader Neodymium for this, halos haven't been a problem.

https://www.astrobin.com/333099/?nc=user
Edited 27 Mar, 2018 03:25
huerbsch
27 Mar, 2018 03:27
I would get the DeepSky RGB and Astrodon for narrowband… I have the Deepsky filters
Lasastard
27 Mar, 2018 13:33
That would probably be my recommendation as well, in hindsight. The price is a bit higher, but I have at least not heard of any such issues. That said, for LRGB I am mostly happy (color representation etc looks good), but I had to put in some effort to make them work in my setup. People's mileage may/will vary, I suppose.
Edited 27 Mar, 2018 13:33
 
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