Star Halos reduction

[shurik]

Hi, I would like to ask if there is a discussion or a script somewhere how to reduce very large halos around bright stars caused by using fast Newtonian and Ha filter. Thanks, Alex

also if there is an info what brand of filters is  more optimized for fast systems to reduce halo artifacts

[pfile]

there is a script called StarHaloReducer, under Scripts > Utilities. it's interactive. try it out. dunno about the filters. i know for a while astronomik was replacing certain Ha filters due to halos.

[troypiggo]

Yes, I went through all of this recently, assuming of course you're referring to Astronomik filters.  Here's my thread on IIS about it: http://www.iceinspace.com.au/forum/showthread.php?t=86869

In there you'll see links to Astronomik's site giving details of what to provide them to get the filters replaced etc.

[Andres.Pozo]

Last year Astronomik replaced my 13nm narrowband filters and the halos disappeared.

I had to send them some photos with halos and some information about the filters and the telescope. The process took some time because they were out of stock of one of the filters, but everything else went very smooth. Since I hadn't to send them my old filters until I had the new ones, I was never without filters.

[Geoff]

+1

[pfile]

that's weird - i have halos from bright stars when using my astronomik 6nm Ha filter. i sent them the images and they basically told me to take a hike.

[Harry page]

Hi

Exchanged mine no probs 

Harry

[pfile]

maybe i should try again. or maybe some 'small' halos are to be expected at f/4?

[Geoff]

that's weird - i have halos from bright stars when using my astronomik 6nm Ha filter. i sent them the images and they basically told me to take a hike.

I recall now that something similar happened to me. I sent in the pics and they (quite politely) suggested that the halos were not due to the filter. So I took two pics-- one through the L filter and one with no filter at all. The first showed a halo and the second did not, so it was clear that the filter was responsible and they replaced the filters promptly.
Geoff

[pfile]

that's good to hear. maybe they just do this to dissuade easily-dissuaded people  . i'll try again.

[troypiggo]

I think they are quite detailed in their assessment of the images you send.  Mine were taken with 10" Newtonian, and I had used an MPCC in the optical train.  They could tell that some of the reflections were due to the MPCC, and some their filter.

That being said, they were also a bit elusive/odd in their reply about the filters they sent back.  They were hinting that they had custom chosen the filters to suit my optics.  I asked them how they knew what other optics I used with their filters (ie I also have a refractor and at the time had an SCT), but no satisfactory answer came back.  I also asked them what the difference was, because on their website and packaging on the filters they sent back, there only appears to be one kind of 12nm filter for each bandwidth.

[shurik]

mine is astronomik too, so I found the recall note on their website and sent a picture plus all info., 3 days no answer or any notes from them...do you guys remember of any email communication with them so I can email that info to a different address maybe..., thanks ,Alex

[troypiggo]

They did take a week or 2 to correspond, so 3 days I wouldn't be too concerned.  Bit reluctant to post someone's full email address here on public forum, but it started with "support@" and the domain name was the filter brand's domain name.  The replies I got back from them were from an astro-shop.com domain.  Just be patient.  My experience, while slight delays between correspondence, was positive.

[pfile]

in my case i have halos in images taken with the canon 200L and also the canon 50 "nifty fifty". i only sent them one image. i should have sent them comparisons; no filter, cls filter, and ha filter. i'm pretty certain the halos come from the Ha filter as it never happens with my OIII filter, nor the CLS...

i'll have to work up the comparisons.