What is a reasonable size for halos ?

[Andywilliams]

My setup =

SW 150pds f5

asi1600mm

zwo 7 position filter wheel with 36mm filters

I seem to be getting very large halos.

I’ve noticed halos before but not this dramatic.

Is there anything I can do to the imaging train in order to reduce these ?

Any tip, tricks or suggestions are most welcomed.

Thanks in advance,

Andy 

 

 

[Starflyer]

Are you getting them in all channels, I'm not near my PC at the moment so can't split the image.

Do you have your filters fitted the right way round? What make are they?

Hold a pencil above the filter. One side will show a single reflection, the other a double, the double reflection side should be towards the camera.

If this is the way you have them fitted try flipping them over.

Edited February 2, 2022 by Starflyer

[teoria_del_big_bang]

11 minutes ago, Starflyer said:

Are you getting them in all channels, I'm not near my PC at the moment so can't split the image.

Do you have your filters fitted the right way round? What make are they?

Looks to be pretty much on all channels, mostly Green and Blue.

I certainly would make sure the filters are the correct way round, there is normally a mark on the outer edge of the filter to say which side points towards the scope/

Steve

[Andywilliams]

I’ll have to look at the manufacturer but I’m not near them at the moment.

I used Ha and Oiii. The worst seems to be the Oiii ? 

I’ll take the filterwheel apart and see if they are the correct way around 👍👍👍

[teoria_del_big_bang]

I have Baader ultra NB and I do get some halos on OIII as well but usually manageable.

Steve

[newbie alert]

Theyre pretty drastic, have you blackened the edges on all things shiney , ie end of the focuser tube, screws, nuts, flocking?

Are you using double filters, is the sensor as close to the filters as poss, are the edges of the filters blackened..

Some blacken the edges of the mirror..

The 1600 is known for its microlensing effect on bright stars

Finally, why are your stars only green? 

I don't get any halos on any of my systems... id have to either find it the cause or change equipment systems... 

[inFINNity Deck]

Hi Andy,

Try step-by-step elimination (so apply each of below steps and take new images before applying the next step):

- turn around the filter wheel

- remove the filter wheel

- remove flattener (if present)

- use a different camera (if available)

ZWO has masks for the 36mm unmounted filters, but those remove other artefacts that those seen here. I have described them on a Dutch forum (opening in Chrome should translate it): https://www.starry-night.nl/forums/topic/maskers-voor-zwo-efw/

The old style ZWO H-alpha and S-ii filters (produced before June 2018) produced concentric halos, which I described here: https://www.starry-night.nl/forums/topic/halos-en-zwo-filters/

HTH

Nicolàs