Bloated stars issue

Hello Smart People!!!!!

I just got a new scope and I'm getting some unexpected results from it. It's a 110mm Orion Eon ED APO f/6. I'm using it with a Canon 70D, a field flattener and the Orion Skyglow Imaging filter. (I get the same results without the filter)

Notice how the redder stars have a little halo/bloat/ring around them? Is that normal from a scope like this? How might I reduce it. I've been shooting at ISO800 for 4 minutes for each image.

I had an 80mm Cestron ED non-APO and I didn't get these little rings.

Attached it a 100% crop of one of the images.

Thoughts?

Jeff

Hi Jeff,

I gets bloated stars when using my 30mm f1.4 lens ... Have assumed it was either: focus issue, thin clouds or sometimes from shooting inside looking through glass doors.

Any of these sound like possible?

- Daniel

It looks like longitudinal chromatic aberration to me.

Ron

That is perfectly normal, it is star color in the stars. Understand that the 110mm eon is actually a doublet and could indeed yield chromatic aberration however this image simply demonstrates stars which are not correctly white balanced and they are surrounded by their actual color. If you align the rgb channels in camera raw before opening the image you will have a more accurate representation of the colors. Also if you select the back ground with the magic wand, invert selection expand 3 pixels, saturate to 50% and then Gaussian blur the selection the entire star will become colored.

I tried your suggestion Calypsob but it only emphasized the halos. Do you mind clarifying the process and maybe posting some sample pictures? Thanks.

Thanks for the info guys, I'll give the suggestion a try and see what I can come up with.

yes, here is a tutorial which spells it out better http://www.astropix.co​m/HTML/J_DIGIT/STARCOL​R.HTM

Thanks Calypsod.