Chroma 3nm halo

[souls33k3r]

Hi there, 

I'm reaching out to all Chroma 3nm NB filters users to find out if they have ever noticed what I am doing right now. 

I purchased the filters from @FLOduring the first lockdown. A few things happened in my life which put a stop to anything I wanted to do and AP was one of them and only just started to process images since I've had the filters so I am a little late on testing. I'm seeing halos!!! I did not notice anything in the individual subs when I was capturing it but then I wasn't expecting much to go wrong with these filters. It's only when I started to integrate the light frames is when the issue became quite evident. The first image that I processed didn't have many bright stars to take notice of the halos but the second image showed them. The first time I noticed them was when using Starnet, all the bright stars had a halo around them. Even though I wasn't happy about the fact that the 3nm still showed too many stars and bloated especially coming from 6nm, I thought that maybe I pushed the data too far and carried on processing the data. The first image was fine, only because it wasn't a fended star field but the second image showed the stars a bit too much for my liking that I really had to do star reduction. 

Now when I got the filters, I did ask if the orientation mattered and I was told that it didn't so I placed the reflective side (top writing) towards the camera and non/less-reflective side towards the scope end. When this issue started to bug me, I noticed that @Ken82mentioned here the filter orientation had to be in a particular way which then took me to a CN thread where it was again mentioned which way the filters had to be. The solution was to flip the filters. When I opened up the FW tonight, I realised that my filters were the positioned the correct (sugggested) way. I still flipped them because I have no other choice.

The scope that I used was EdgeHD 8" with ASI1600MM-COOLED camera. 

This is what my individual subs look like

Bottom right hand corner:

Middle:

It might not look much from these screenshots but I could definitely see this on my PC. OIII for the "middle" screenshot doesn't show much but in the corners it still does. Chose the corner because that's where the bright star was positioned. 

Below is the integrated SII which shows the banding for the middle image

The integrated subs for all channels (bottom right corner) 

The integrated subs for all channels (middle) 

Any advice/help is much appreciated. Thanks. 

 

[Laurin Dave]

Hi Souls..  I believe that is a microlensing affect from your camera and nothing to do with the filters.. obviously best to have them the right way round though 

Dave

Edited November 15, 2020 by Laurin Dave

[souls33k3r]

Unfortunately it's not the microlensing effect. That has a total different pattern and doesn't produce halos. 

[Whirlwind]

The effect is due to Newton's rings

https://en.wikipedia.org/wiki/Newton's_rings#:~:text=Newton's rings is a phenomenon in which an,the effect in his 1704 treatise Opticks

It's known on ASI1600s and believe it is an interaction between the cover slip and microlens of the sensor.  You are hence not likely to be able to get rid of the problem (because you can't tilt angle between these two glass elements.  It's probably occurring now because the filters are higher quality than previously (which probably masked the issue).

 

[david_taurus83]

I suppose the next step would be to try out a different camera to rule out the filters?

[souls33k3r]

I'm certainly not the first person to use this combination of camera and filters because otherwise you'd be hearing about it all over the web which we're not.

Unfortunately I don't have enough money to be spending on a different camera and neither can I ask someone for it. 

Edited November 15, 2020 by souls33k3r

[fireballxl5]

This doesn't look like "regular" haloing to me and I have experience from the bad batch of Baader OIIIs from 2014😉

I now have a set of Chroma 3nm and although not orientated as commonly recommended in my QSI camera (with FSQ85) they are essentially halo-free. I emailed Chroma earlier this year to check this and they confirmed that filter orientation did not matter.

Hope this helps, 

Andy

[souls33k3r]

1 minute ago, fireballxl5 said:

This doesn't look like "regular" haloing to me and I have experience from the bad batch of Baader OIIIs from 2014😉

I now have a set of Chroma 3nm and although not orientated as commonly recommended in my QSI camera (with FSQ85) they are essentially halo-free. I emailed Chroma earlier this year to check this and they confirmed that filter orientation did not matter.

Hope this helps, 

 

True, it doesn't look like a regular halo-ing and I can promise you these halo in the "bottom right corner" image (in the integrated) is so prominent on the TV screen that I use than on the mobile phone. 

I checked with FLO and they were kind enough to tell me the same thing thay orientation doesn't matter but then like I said there's a thread on CN which was from this year shows exactly that the orientation does matter. Now even though my filters were in the "suggeted" orientation, it still produced this. Now I've flipped them to see what happens but can't test them out until wr have the next clear night which God knows when is going to be happening. 

[newbie alert]

Don't look like a halo, or a micro lens effect to me.. 

Are you using any other filters in the imaging train? And are the filters as close to the sensor as poss? Maybe  from the glass in the reducer?

[Laurin Dave]

This is what I get with my ASI1600 and Astrodon Oiii and Ha filters...  this is the bright star in the Witches Broom, Ha shows it most.  My guess is that its the lack of other filter artefacts that allows it to show through . Might have a bit of tilt to although doesn't affect the star shapes 

 

Edited November 15, 2020 by Laurin Dave

[souls33k3r]

13 minutes ago, Laurin Dave said:

This is what I get with my ASI1600 and Astrodon Oiii and Ha filters...  this is the bright star in the Witches Broom, Ha shows it most.  My guess is that its the lack of other filter artefacts that allows it to show through . Might have a bit of tilt to although doesn't affect the star shapes 

 

OK but this is a big boy star. The stars that I am seeing these halos and banding are on smaller stars but bigger of the bunch if it makes sense. 

[groberts]

I'm interested and a little concerned by this as I've just purchased a set of Chroma filters but not yet fitted and used. 

Souls - could you please point me towards the CN thread mentioned + decribe how you indetify one side of a filter from the other?

Graham

[souls33k3r]

4 minutes ago, groberts said:

I'm interested and a little concerned by this as I've just purchased a set of Chroma filters but not yet fitted and used. 

Souls - could you please point me towards the CN thread mentioned + decribe how you indetify one side of a filter from the other?

Graham

Sure mate, it's https://www.cloudynights.com/topic/715162-chroma-3nm-orientation/

[Ken82]

Interesting topic. I seen a similar halo/diffraction  effect but only with my 7nm baader filter and the star was also off axis. 

I’ve yet to see a repeat of this affect with the 3nm chroma filters I now use. 
 

looking at some of the more recent data I’ve collected if I was to mega scrutinize the garnet star (which is also off axis) maybe it is there but then it’s so small it’s not noticeable. 
https://drive.google.com/file/d/1JHiJTEOlYGJljmBnkXRBiEjRFcWGtxm1/view?usp=drivesdk

https://drive.google.com/file/d/1o7GcEvZbTC8D5nBveJbb8TuliEZmWpoi/view?usp=drivesdk

There is a lengthy thread on cloudy nights which may help out but unfortunately there is no defining answer.

https://www.cloudynights.com/topic/728648-reflection-artifacts-in-the-asi6200/?fromsearch=1

I think it is just a consequence of the scope/filter/camera combination. You may find the same filters/camera wouldn’t have this effect on a different scope. And then the same scope may not have it using a different filter set and or camera. 
 

I would be interested to hear what chroma think ? 
 

ken 

 

 

[souls33k3r]

 

30 minutes ago, Ken82 said:

Interesting topic. I seen a similar halo/diffraction  effect but only with my 7nm baader filter and the star was also off axis. 

I’ve yet to see a repeat of this affect with the 3nm chroma filters I now use. 
 

looking at some of the more recent data I’ve collected if I was to mega scrutinize the garnet star (which is also off axis) maybe it is there but then it’s so small it’s not noticeable. 
https://drive.google.com/file/d/1JHiJTEOlYGJljmBnkXRBiEjRFcWGtxm1/view?usp=drivesdk

https://drive.google.com/file/d/1o7GcEvZbTC8D5nBveJbb8TuliEZmWpoi/view?usp=drivesdk

There is a lengthy thread on cloudy nights which may help out but unfortunately there is no defining answer.

https://www.cloudynights.com/topic/728648-reflection-artifacts-in-the-asi6200/?fromsearch=1

I think it is just a consequence of the scope/filter/camera combination. You may find the same filters/camera wouldn’t have this effect on a different scope. And then the same scope may not have it using a different filter set and or camera. 
 

I would be interested to hear what chroma think ? 
 

ken 

 

 

Thank you for the link and your input Ken. The CN thread is mostly tested on a super bright star which I won't ever be going anywhere near to but your data has somewhat smallish star in the elephant trunk image. Did you try flipping the filters afterwards to see if this effect goes away? 

This really worries me because I've paid a good chunk on these filters which are going to be worthless if they are not going to work for me. It really is heart breaking to say the least. 

[whipdry]

I had a problem with my Chroma OIII filter, got in contact with Chroma direct & sent them images showing the issue. They replied asking that I return it for a replacement, also supplied the RMS labels for the return... I even received the replacement filter before I managed to send off the old one! 

Ended with an email from them explaining that when tested a thin layer of lubricant had found its way onto the surface of the filter which had caused the issue...  still a little baffled by this but can't believe the standard of service!

 

Peter

 

[Whirlwind]

1 hour ago, souls33k3r said:

 

Thank you for the link and your input Ken. The CN thread is mostly tested on a super bright star which I won't ever be going anywhere near to but your data has somewhat smallish star in the elephant trunk image. Did you try flipping the filters afterwards to see if this effect goes away? 

This really worries me because I've paid a good chunk on these filters which are going to be worthless if they are not going to work for me. It really is heart breaking to say the least. 

They aren't worthless.  They are just of such a quality that you are showing up other effects in your system.  Newton rings occur when you have a spherical surface touching a planar surface.  For the ASI1600 this occurs because you have the microlens (spherical surface) touching a planar surface (the cover slip).  Sometimes you can tilt the system so that the light rays aren't parallel to the surface (so you don't get the effect) but if it occurs because of the camera then it's not likely to help - which I suspect in this case because of the small rings being visible.  Both CCDs and CMOS can show this effect (and depends on the design).

You can manage this from a software perspective by masking the stars and adding in a gaussian blur or similar (or you could replace with RGB stars).  It's also worth remembering that using 3nm filters is to get the best out of the nebulae which you can still do. 

Here are some other examples using different set ups.

https://www.cloudynights.com/topic/728648-reflection-artifacts-in-the-asi6200/

 

Edited November 15, 2020 by Whirlwind
Provide examples

[souls33k3r]

Unfortunately they are worthless to me if it doesn't work the way they are intended. I don't have to put up with software wizardry to fix something that shouldn't even be present in the first place. I really can't put up with this especially I paid nearly £500 per filter. If I was imaging a bright star then yes it makes sense for the microlensing effect to be very much visible and may even have the newtonian rings but on a small star? Certainly something is not right here. 

[groberts]

I take comfort that there are many accomplished imagers on Astrobin using my camera (ZWO ASI1600MM-Cool) with these filters and getting great results.  I guess I'm about to find out!

I suggest three lines of enquiry:

• With the retailer
• With the manufacturer
• Perhaps post on CN for wider discussion.

Keep us all in the loop with any feedback + good luck.

Graham   

  

[knobby]

I'd contact Chroma as @whipdry says, they sound very helpful 👍🏻

[knobby]

I maybe talking rubbish but is it worth trying to bin as the 1600 sensor at 1400 or 2000 mm is quite a high sampling ?

[Ken82]

2 hours ago, souls33k3r said:

 

Thank you for the link and your input Ken. The CN thread is mostly tested on a super bright star which I won't ever be going anywhere near to but your data has somewhat smallish star in the elephant trunk image. Did you try flipping the filters afterwards to see if this effect goes away? 

This really worries me because I've paid a good chunk on these filters which are going to be worthless if they are not going to work for me. It really is heart breaking to say the least. 

Hi souls sorry just to be clear the image I posted was from a 7nm baader filter and not my chroma filters. I haven’t seen this with my chroma filters yet and I’m very very pleased with them. 

I didn’t change the orientation of the baader filter as this is a mounted filter and can only be screwed into the FW in one orientation. 

Honestly I wouldn’t be upset over this just yet, both chroma and FLO have exceptional customer experience so I’m sure they will come to an acceptable conclusion. 

Do you have a different scope you could try ? Where are you I could give you a lend of a refractor if your Midlands ?

You may even find by changing the orientation it’s resolved the issue ?! Although chroma now say the orientation doesn’t matter I know they recommend changing if there is an issue. And I’m sure I recall reading on CN someone having to do this which solved the issue. 

As I suggested earlier let’s see what Chroma think about it first.

ken 

 

[Ken82]

Another thing I’d look at is ensuring the camera/filters are absolutely square to the focuser/scope.
 

The odd star reflection only happened to me using the asi 6200 and baader filter when it was connected via 2” nosepiece so clearly not square. 

And I’ve been using that particular baader filter for some years without seeing that effect. My initial thoughts were oh c**p it’s the camera ! But this wasn’t true. 
 

ken 

[souls33k3r]

49 minutes ago, groberts said:

I take comfort that there are many accomplished imagers on Astrobin using my camera (ZWO ASI1600MM-Cool) with these filters and getting great results.  I guess I'm about to find out!

I suggest three lines of enquiry:

• With the retailer
• With the manufacturer
• Perhaps post on CN for wider discussion.

Keep us all in the loop with any feedback + good luck.

Graham   

  

Yeah I absolutely went for these filters because of their reputation, the results achieved and of course pairing it with the camera that I have. I just wanted to get in touch with the community here to see what anyone else thinks about it or if they have experienced it themselves. 

Will get in touch with FLO tomorrow and see what plan of action we come up with. Will keep you posted Graham. 

[souls33k3r]

49 minutes ago, knobby said:

I'd contact Chroma as @whipdry says, they sound very helpful 👍🏻

I think I'll go via FLO since I bought these filters off them. FLO are great and I take comfort in the fact that I'd be well looked after as always. 

 

46 minutes ago, knobby said:

I maybe talking rubbish but is it worth trying to bin as the 1600 sensor at 1400 or 2000 mm is quite a high sampling ?

I haven't thought about binning but not sure how that's supposed to help with this mate? 

37 minutes ago, Ken82 said:

Hi souls sorry just to be clear the image I posted was from a 7nm baader filter and not my chroma filters. I haven’t seen this with my chroma filters yet and I’m very very pleased with them. 

I didn’t change the orientation of the baader filter as this is a mounted filter and can only be screwed into the FW in one orientation. 

Honestly I wouldn’t be upset over this just yet, both chroma and FLO have exceptional customer experience so I’m sure they will come to an acceptable conclusion. 

Do you have a different scope you could try ? Where are you I could give you a lend of a refractor if your Midlands ?

You may even find by changing the orientation it’s resolved the issue ?! Although chroma now say the orientation doesn’t matter I know they recommend changing if there is an issue. And I’m sure I recall reading on CN someone having to do this which solved the issue. 

As I suggested earlier let’s see what Chroma think about it first.

ken 

 

Cheers for the super valuable inputs Ken, ah I thought the image of elephant was from the 3nm filters. Jesus, you did give me the scare there mate

Yeah I don't doubt FLOs customer service but before I started to bug them, I thought I'd check here first and see what users of Chroma 3nm experienced and apologies I should've asked you first before tagging you but made sense in my head at the time to do so because it was your super useful thread here which lead me to the CN thread and also I thought it would be best to hear from you since you noticed the issue quite recently so it might be something fairly new people have started to notice. 

Too kind for offering to lend me a refractor mate, I'm no way near Midlands unfortunately but I do have a refractor of my own. I am happy to test this out with the refractor but before I do that, I'd like to go back to my EdgeHD scope and see what that stars behaviour looks like after that I've flipped the filters. 

Yeah the filters and camera are square to each other.