Bright star halos and reflections

[Miguel1983]

Hi,

i’m aware this is what to expect on bright stars, but surly something must help in avoiding these halos. 
The image below is from my Ha data of IC443 with 4m exposures.

Any tips are welcome 🙏 

[Davey-T]

Which of your selection of equipment are you using, looks like reflections off something maybe sensor window.

Dave

[newbie alert]

It's microlensing effect from the sensor...

Is it a zwo 1600 or a qhy 163 by any chance??

[Miguel1983]

thanks for the reply

Gear used was the Esprit 120 + TS 0,75 reducer + ZWO OAG + ZWO EFW + ZWO ASI 1600mm-Pro

I had the same issue on M45.

[newbie alert]

2 hours ago, Miguel1983 said:

thanks for the reply

Gear used was the Esprit 120 + TS 0,75 reducer + ZWO OAG + ZWO EFW + ZWO ASI 1600mm-Pro

I had the same issue on M45.

You will have it on all bright or semi bright stars.. don't be chasing it as a reflection ..

[Miguel1983]

19 minutes ago, newbie alert said:

You will have it on all bright or semi bright stars.. don't be chasing it as a reflection ..

Yes i'm aware of that, but someone may have some tips to reduce the affect, other than less exposure time of course.

I think i'll avoid targets like these for a while, i'm still getting used of the gear and Pixinsight, so i'm better of choosing a galaxy next time.

[Yawning Angel]

You can run Starnet to extract the star layer, then clean up the debris left over before recombination. Not fully automatic, but it’s an option that can give good results

[wimvb]

15 hours ago, Miguel1983 said:

getting used of the gear and Pixinsight

A proper mask and blending the offending region with a less stretched version works reasonably well to remove this microlensing artefact.

The top star in this image has the same problem, but I was able to reduce it enough for it not to be a nuisance anymore. 

https://www.astrobin.com/397054/B/?nc=user

[Miguel1983]

22 minutes ago, wimvb said:

A proper mask and blending the offending region with a less stretched version works reasonably well to remove this microlensing artefact.

The top star in this image has the same problem, but I was able to reduce it enough for it not to be a nuisance anymore. 

https://www.astrobin.com/397054/B/?nc=user

Thanks Wim, my problem is just getting to know Pix, it has a steep learning curve for someone who works construction on weekdays 😉

[wimvb]

15 minutes ago, Miguel1983 said:

Thanks Wim, my problem is just getting to know Pix, it has a steep learning curve for someone who works construction on weekdays 😉

If you haven't found these already:

https://www.easypixinsight.com/

https://www.lightvortexastronomy.com/tutorials.html

https://www.harrysastroshed.com/Pixinsighthome.html

And a bit more advanced, but a real treasure trove:

http://pixinsight.com.ar/

[david_taurus83]

I've found its dependant on the full optical system. I got results like that with a Hotech flattener on my 71mm. But with my WO flattener I could take 15 minute subs on the Horsehead with minimal microlensing. It's there, but not as bad. Try experimenting with turning the filters/filterwheel around and if possible put a spacer between the FW and camera.

 

[Miguel1983]

2 minutes ago, david_taurus83 said:

I've found its dependant on the full optical system. I got results like that with a Hotech flattener on my 71mm. But with my WO flattener I could take 15 minute subs on the Horsehead with minimal microlensing. It's there, but not as bad. Try experimenting with turning the filters/filterwheel around and if possible put a spacer between the FW and camera.

Won't that induce more vignetting ?

And i have little room left with my EFW and OAG crammed in 55mm (-backfocus 6,5mm)

 

[david_taurus83]

14 minutes ago, Miguel1983 said:

Won't that induce more vignetting ?

And i have little room left with my EFW and OAG crammed in 55mm (-backfocus 6,5mm)

 

Possibly, I had 36mm filters so had a bit of wiggle room. You could try turning the FW around and see if it lessens the reflections. Have you got the SW flattener? Does it do it with that?

Ps. Off topic, but how are you getting on with that reducer? Someone was asking recently about reducer options for the Esprit 80.

[Miguel1983]

2 hours ago, david_taurus83 said:

Possibly, I had 36mm filters so had a bit of wiggle room. You could try turning the FW around and see if it lessens the reflections. Have you got the SW flattener? Does it do it with that?

Ps. Off topic, but how are you getting on with that reducer? Someone was asking recently about reducer options for the Esprit 80.

Currently i'm using the TS 0,75 reducer, haven't used the SW Flattener yet.

The TS reducer/flattener is good, i posted some testshots with it here :

 

I'm not sure it will fit the Esprit 80 out of the box, might need an extra adaptor for that.

Edited December 28, 2019 by Miguel1983

[david_taurus83]

@AndyThilo