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Are my Ha halo problems now a thing of the past?


MikeD

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I hope so...... I have just received a free replacement 12nm Ha filter from Astronomik.

After Tony mentioned it (in this thread) I sent an email to Gerd Neumann at astronomik and he sent me a replacment filter the next day F.O.C.:icon_eek:

Next clear night I was planning to get some colour for my ngc7331 image but now I am chomping at the bit to target the heart of the heart neb to see if the halo's are indeed a thing of the past.:)

Mike.

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Steve, I hope so. Gerd told me "You have one of our filters with a production error" so I guess that means all the Ha filters should be anti halo .:icon_eek:

The filter I got to replace my 13nm was a 12nm.

Clear skies is what I need to provide the answer.:)

Mike.

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I think I could live with that Aza.

Conditions were not good last night ,big moon fireworks smog and high thin cloud between banks of thick cloud.

I did grab two 5 minute exposures to compare with two 5 minute exposures with the old filter taken last year under much better conditions.

The quality of the shots from last night make it hard to be sure that the halos are gone but I think it is obvious that there is a marked improvement so I am a happy camper.

the two subs from each image were stacked with no flats or darks and then exactly the same adjustments in levels and curves were applied to each.

Mike.

post-13376-133877408415_thumb.jpg

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I have been watching the posts on this subject with great interest as I bought an Astronomik 13Nm Ha filter in April 2006 and use it very rarely but mine seems to be OK. I have attached an image taken with my SXVF-H9C (note this is an OSC) comprising of 17 subframes of 200 seconds each, binned 2 x 2. Looking at the image, would you say that my particular filter is not faulty? - I cannot see any halo and certainly nothing like Mike's very interesting comparison set. Comments appreciated, thanks!

post-13675-133877408424_thumb.jpg

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Nice results with newer Astronomik. I had enough of halos even after Eric Vesting replaced all my filters bought 2-3 years ago with new ones (outstanding service). The new filters were slightly improved but I had already decided to go Astrodon.

If you add a UV/IR cut filter this may reduce residual halo further but I have to agree your halos are a lot better and PS-CS3 will remove any minor trace when stacked and stretched. I found the O3 filter gave the worse halos and the new filter made no difference and Eric said it may be the MPCC I used with Newtonian.

Glad thing look better for you and brilliant service from the Astronomik Guys.

JohnH.

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Just wondering if this "halo" effect occurs with the other Astronomik filters ? I've seen mentioned in this thread both Ha and O3. Are both the CCD and visual grades similarly afflicted ?

The problems were put down to a production error so one would assume they should be able to identify all the filters affected by their serial numbers ?

Andy

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Mike those halos are so soft and easily removed with little trace in PS using marquee tool and curves, a beautiful image by the way twisting tower of nebulosity have come out extremely well - a real winner.

Andy - I had halos on all my filters bought 3 years ago including LRGB although S2 filter had no halo at all - I sent Erik Vesting the Serial Nos he requested and he replaced them within a week from Hamburg, colours had a very minor improvement with Ha but O3 remained bad. My old NB halos where like Arrans had a bright circumference circle making it hard to PS out.

Baader filters seem free from these halos and O3 is 8.5nm v 12nm. It has been said 12/13nm are not really NB and the trend has been for narrower filters as the increased S/N ratio really improves the faintest/finest detail. The LRGB by Baader are outstanding and comparable with Astrodon but 30% cheaper than Astrodons.

JohnH.

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John,

Many thanks for the reply and the attachment which shows the issue at hand.

I haven't used my Astronomik filters in anger yet so it'll be a worthwhile exercise to do some test shots as per your example just to see if I have a problem before I spend lots of time imaging (hopefully) with them. I do appreciate that these things can be corrected by various software packages but I don't want to spend excessive time sorting out on the computer either.

Best wishes, Andy

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