Antlia Ha 3nm HALO :(

[Emuhead (Andrew)]

My first sub with these filters.. Ha 3nm filter.. Halo shown.

This is a mag 3.8 star belonging to the Dolphin Head nebula. SH2-308

I was using an f/3 reducer, and ive heard the faster the optics the more likely a halo can occur. There were no halos on the Oiii 3nm filter, which is interesting.

Very very sad face.

[AdamJL]

You raised the issue…fast f/ratios can do it. You could always try exchanging it to see if you can get a better copy. That said, halos with these filters are rare, so you could have some luck exchanging it.

Or sadly, pony up for the Chromas…

[AnakChan (Sean)]

Did you try flipping the Ha over? (i.e. got the correct side facing the camera vs the OTA)?

[Emuhead (Andrew)]

Originally Posted by AdamJL

You raised the issue…fast f/ratios can do it. You could always try exchanging it to see if you can get a better copy. That said, halos with these filters are rare, so you could have some luck exchanging it.

Or sadly, pony up for the Chromas…

All i do i pony up.. this hobby takes you to all new levels of wallet opening. Im on the exchange track, hopefully that comes through.

Originally Posted by AnakChan

Did you try flipping the Ha over? (i.e. got the correct side facing the camera vs the OTA)?

I looked into that, super reflective side without double reflections to the sky & the side with the double reflections pointing to the sensor, so its not that but could try flipping it anyway.. see what happens.

[Emuhead (Andrew)]

The reflection is only 3.6mm from the sensor, so the 2600MM window, which leads me to think its tilt related. Aiming to address tilt, try a different reducer, and see the outcome of that.