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Curious, at last I found an Oiii filter that works.


lensman57

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Hi,

I bought an Astronomik Oiii CCD filter from a seller on ABS UK, it is the bug standard 12 nM variety. I had a lot of very large halo problems with my Baader 8.5 nM Oiii filter,  no matter which scope I used, doublet, triplet or Newt to extent that I was about to give up NB imaging altogether . Last night I took a chance and tried the new filter as part of SH2-132 Bi colour imaging and this is the Oiii stack with just a Histogram stretch with STF parameters applied and an ABE, the result : No Halos. This was the result of 8 x 900s subs with my WO Megrez 72 FD DDG @ F4.8 and a TRF 2008 FF/FR.  Now I have the confidence to go to 1800s subs for Oiii knowing that the dreaded Halo is not going to show up, the clouds are another problem. I guess Astronomik have laid the ghost of their earlier haloing versions of the NB filters to rest now. For what is worth I got better FWHM with Oiii filetr than I did using the Baader 35 nM Ha filter, although the sky was a bit darker than when I started imaging with the Ha.

Regards,

A.G

post-28808-0-19569200-1406651297_thumb.p

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Hi AG

All my CCD filters are astronomik never had a problem with them.

Steve

Hi Steve,

I have the RGB ones, Type 2c and they are great. I did post about the Baader filter not being right on my equipment but no conclusion was reached.

A.G

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I also just replaced my Baader - but with an Astrodon 3nM OIII. I've had some good images with the Baader (Veil neb had a strong OIII response, as did the Cateye), but I was also getting star bloat on bright stars. Anyway I went for the Astrodon for better contrast and alegedly good immunity from moonlight. Two nights ago I took a trial image of M27 in OIII to try it out and it works very well, albeit my mount was not tracking well (I know why - someone had walked into it and I need to get spanners on it to set the worm alignment again). Anyway, looking past the eggy stars I can see there is no star bloat.

OIIISTcrop_zpsc434b233.jpg

ChrisH

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Thank you Louise, Chris.

My Baader Ha and Sii work just fine it was just the Oiii and the problem was not just the star bloat huge halos. I posted a Bi colour of a sort as an experiment, please see the link, and it explains it all. Astrodon is the best  but the price is rather an overkill for my imaging skills. Amazing capture of the M27, Chris  as usuall.http://stargazerslounge.com/topic/221347-ic5070-bi-colour/

Regards,

A.G

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Thank you Louise, Chris.

My Baader Ha and Sii work just fine it was just the Oiii and the problem was not just the star bloat huge halos. I posted a Bi colour of a sort as an experiment, please see the link, and it explains it all. Astrodon is the best  but the price is rather an overkill for my imaging skills. Amazing capture of the M27, Chris  as usuall.http://stargazerslounge.com/topic/221347-ic5070-bi-colour/

Regards,

A.G

Hmm... I wonder if there's been a bad batch of OIIIs. Have you tried contacting the dealer, or even Baader directly?

Cheers

Louise

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Hmm... I wonder if there's been a bad batch of OIIIs. Have you tried contacting the dealer, or even Baader directly?

Cheers

Louise

I was wondering the same thing. There have been a few people with halo issues with the Baader 8.5nm OIII. I recently got the same filter and haven't had an problems so far but I have only shot 3 images with it.

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Hmm... I wonder if there's been a bad batch of OIIIs. Have you tried contacting the dealer, or even Baader directly?

Cheers

Louise

Hi Louise,

I have had this for a few months now but for the love of god I can't remember where I bought it from. I know that the Ha was from an SGL  member but no recollection of the Oiii. The Sii was from FLO.

A.G

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Interesting comments about the Baader filters. I'm not seeing any gross halos with mine.

 This a 20 minute sub straight out of the camera

14769377396_789f201d57_b.jpg

NGC6888_1200sec_filter6_003332_NGC6888_0004

Altair 115 triplet, Photoline .79 reducer, SX filterwheel and Atik 428EX

Could it be a bad batch? Or optics related (reflections or the optics bloating that particular frequency)?

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Interesting comments about the Baader filters. I'm not seeing any gross halos with mine.

 This a 20 minute sub straight out of the camera

NGC6888_1200sec_filter6_003332_NGC6888_0004

Altair 115 triplet, Photoline .79 reducer, SX filterwheel and Atik 428EX

Could it be a bad batch? Or optics related (reflections or the optics bloating that particular frequency)?

Well I'm guessing that particular image is not stretched so you won't see faint halos, obviously if the halos were gross then my Baader OIII filter would have been returned immediately. However, it doesn't really hit you until you process the images and combine with Ha and SII and then you realise the OIII stars are fatter and producing blue halos.

ChrisH

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Interesting comments about the Baader filters. I'm not seeing any gross halos with mine.

 This a 20 minute sub straight out of the camera

14769377396_789f201d57_b.jpg

NGC6888_1200sec_filter6_003332_NGC6888_0004

Altair 115 triplet, Photoline .79 reducer, SX filterwheel and Atik 428EX

Could it be a bad batch? Or optics related (reflections or the optics bloating that particular frequency)?

This is what I got on the same target while testing the filter with a Newtonian, Quattro 8s  rather than my APO. The same results, large halos. Again this one is had a simple stretch with STF parameteres and an ABE. The focus was just rough as it was a test .

Regards,

A.G

post-28808-0-20293500-1406800246_thumb.j

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 The focus was just rough as it was a test .

I wonder if this would affect it?

I don't have the OIII layer to hand but this is from an f/5 Newt and I pushed the OIII really hard but didn't get too much bloating around the stars. I haven't done any star touching up other than a global 'make stars smaller' from Noel's actions.

post-5915-0-78173600-1406808004_thumb.jp

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I wonder if this would affect it?

I don't have the OIII layer to hand but this is from an f/5 Newt and I pushed the OIII really hard but didn't get too much bloating around the stars. I haven't done any star touching up other than a global 'make stars smaller' from Noel's actions.

attachicon.gifpost-5915-0-95564600-1404335689.jpg

That is a very nice image with nice tight stars.  I first blamed the ED 80 for the halos, then when I used the triplet Apo I got the same result, I then tested it with the Quattro 8s  and halos were still there. I am going to give it another go with a filter box rather than wheel to see if it has something to do with distancing. But I guess now that the Astronomik is working I may stick to it and save for a 5 nm Astrodon as 12 nm is a lttle too wide  for some targets.

Regards,

A.G

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