Hi

I generally image using a Meade 80mm f6 APO refractor and a DSI II camera.  Most of my images both single and stacked show background stars in various colours instead of white. My DSI I camera shows a similar problem. I have checked the scope carefully doing star tests with a high power eyepiece and it shows no sign of bad collimation or chromatic abberration. Any comments? I could attach a sample  image but I did not know how to attach to this message.

Cheers Peter

 

 

 

Hi, Peter

why do you think this is a problem? Stars really *do* come in different colors, after all

To attach a sample image, click the "Options" tab at the top of the message & upoad the file...jpeg is best.

Chuck

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Chuck Reese
CDIP Certified: Nebula, Galaxy, Solar System, Stars & Clusters Imager
CDIP Mentor: Nebulae & Solar System Categories
For information on the Certified DSI Imager Program, see:
http://autostarsuite.net/forums/1427/ShowForum.aspx

Hi Chuck - I have uploaded my latest of the Omega nebula in Sagittarius. This consists of 30x1minutes stacked. The single images show similar doubfully coloured stars. Incidently, I was using a Hutech light pollution filter but it made no difference when I imaged without it.  Cheers Peter

Peter, other than an overall red glow they look OK. How far North are you/ South is the object? Part of the red stars may be the amount of atmosphere you have to image thru.

BTW, nice image. What were the details; scope, DSI, length and number of exposures, processing, etc.?

JimT

OK, I see it now. Here are a couple of things you can do/play around with:

- You can reduce the saturation using the Hue/Saturation tool in photoshop. You can apply to the entire image, or just select the stars only & apply to them.

- You can reduce the color intensity setting in Envisage (under the 'Color" dialog, there is a slider there)

- You can try "color soft" vs. "color sharp", radio buttons also under the "Color" in Envisage.

Finally, be sure to keep your darks frame temps closely matched to your light frames this time of year - hot pixels will show up as brightly colored "stars" on the OSC cameras.

HTH,

Chuck

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Chuck Reese
CDIP Certified: Nebula, Galaxy, Solar System, Stars & Clusters Imager
CDIP Mentor: Nebulae & Solar System Categories
For information on the Certified DSI Imager Program, see:
http://autostarsuite.net/forums/1427/ShowForum.aspx

Thanks Jim - Details are Meade 80mm f6 APO refractor, DSI II camera, Idas light pollution filter, guided, 30x1minute images, graded, aligned both translate and rotate, combined, stretched in ImagesPlus.  My location is in Sydney, Australia at 34degrees south so at present Sagittarius is almost directly overhead. Viewing conditions were dark moon, good with light dew but none on my 80mm.

Thanks Chuck - I will try all your tips when conditions permit.  Cheers Peter

 

 

 

Hey, Peter

Didn't realize you are in Oz, LOL - the "this time of year" temperature observation assumed you were in the northern hemisphere. This time of year for you the temp variance will be more forgiving...

Chuck

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Chuck Reese
CDIP Certified: Nebula, Galaxy, Solar System, Stars & Clusters Imager
CDIP Mentor: Nebulae & Solar System Categories
For information on the Certified DSI Imager Program, see:
http://autostarsuite.net/forums/1427/ShowForum.aspx