Second attempt at f3.3 through ED80 Horsehead and Flame

[CoolhandJo (Paul)]

Well, after the advice given on the first attempt, here is the second attempt!

No clouds this time so got 30 60xsec shots f3.3 Skywatcher ED80, DSI II, guided LX200 10" with DSI.

I used envisage to increase size and pixel fraction.

Used Noel's tools in photoshop to remove skyglow etc.

I am happy with it. Still playing around with the data!

Thanks in advance

[peeb61 (Paul)]

Very nice Dr Paul,
Captured nicely.

Whats causing the big halo around Alnitak? Just curious.

Paul

[CoolhandJo (Paul)]

Thanks Paul. Not sure about the Halo? Always seem to get it when I image this region. Maybe someone else can offer some advice? If I had to guess I would say over exposure on Alnitak as I tried to stretch the image to bring out the horse etc.

[atalas]

Originally Posted by CoolhandJo

Thanks Paul. Not sure about the Halo? Always seem to get it when I image this region. Maybe someone else can offer some advice? If I had to guess I would say over exposure on Alnitak as I tried to stretch the image to bring out the horse etc.

Hi Paul

Great effort mate! well,at f/3.3 It is very fast and using a 10"SCT I would expect a large halo but I kinda like It.



There is ways to reduce It selectively and you would have to start learning to using "Hide all blurred layer mask" to get the best results.

Here's a link that might help but not knowing what you know about PS It might be a bit too advance for you. http://www.rdelsol.com/Presentations.html



Of cause these things are a lot easier to explain to someone face to face as then you can see first hand what PS tools are already known.

Anyway hope you find the link useful and of cause you could always email me If your not sure about curtain aspects of the tutorial.

[CoolhandJo (Paul)]

Thanks Louie. That makes sense (the f3.3 speed). I will take a look and try and absorb!

[AlexN]

It could also be a reflection caused by a glass element in the imaging train.. I get reflections similar to this due to my UV/IR filter on my QHY8...

[CoolhandJo (Paul)]

Thanls Alex. So how can you determine if it is optical reflection? And more importantly how can it be corrected ? Anyway I suppose for the purposes of the dsi 2 and the low exposure time its not an overall issue. This may be corrected by longer exposure and less stretching of the image perhaps?

[AlexN]

you can see if its an optical reflection by moving the star within the frame and seeing if the halo moves with respect to where the star moves... if the star is in the left of the field, the halo will be offset from the star to the left. if its in the right of frame, the halo will offset to the left. when centralised the halo should be concentric to the star...

Longer exposures in my experience make matters worse, heavy stretching does it as well... It can be corrected by moving the reflection causing element further from the imaging plane, or if its from a filter, you could buy a higher quality anti-reflective filter..