color bloom in images

[Mukv]

Greetings

I need help to identify where to look to resolve an issue with my images,it seems to be present in all images. is it something simple like the fool at the keyboard and mouse not knowing what to do?

as you can see in the screen capture there is a distinct color bloom present fairly central and high on the image.

I'm not sure where to look to address this issue, is it in the optical train as in sensor(cleaned) coma corrector( cleaned) secondary mirror(looks clean with minor dust) main mirror(cleaned)

the equipment list from camera to mirror is

Canon 5Dmk2 un modded

SW coma corrector

SW 300P DS

I have no filters in the optical train only CC my sky has quite high level LP. my brain has many dead neuron's.

and advise please to preserve dying neuron's.

Andy

[Stargazer33]

How long were your subs? Do you still get the same problem with 20-30" subs?

[ollypenrice]

What effect do flats have?

Is the inside of the scope truly reflection-free? Flocking might help.

FInally, even with Takahshi glass, a cooled CCD camera, flats and a seriously dark site I still get mild colour gradients in images. C'est la vie. That is where ABE or DBE in Pixinsight come to the rescue. You need them!!

Olly

PS Could light be entering the Newt from below?

[Mukv]

Greetings

the screen cap is of PS the image is a stack of 17 images

1   X  240 second iso 1600

5   X 180 second iso 1600

11 X  30 second iso 1600

 stacked in DSS and yes the bloom seems to be present in all exposures, I have 2 street light less than 75m

  away and there could be a possibility of light contamination getting into the tube I will explore this tonight

even if it's cloudy I can still point the scope and look into the light paths from the street lighting.

I may have to be super nice to the cash strapped council and ask them to shield 1 but the other is sideways to me

and a shield would be impractical.

Andy

[Mukv]

thanks guys.

I was climbing all over the obsy and scope tonight and picked targets in different quadrants of the sky with the outcome that supports the external light contamination,

I now have to work on a few environmental adjustments.

Thanks for your valuable insight into my problem, the kettle is always on if your in my area and you fancy a visit.

Cheers

Andy