Stars have triplicated RGB versions from DSS !

[halli]

Hi

I have recently processed an image of the crescent nebula in DSS.   The output image  appears to have triplicated stars in R, G and B when looked at magnified !  

I have attached the image which I have stretched in PI without any further processing.

 Not experienced this before and I am using exactly the same settings as I normally do in DSS.  The original lights are fine,

The image has quite a lot of stars, and has 4 light frames of good data of 1000s duration stacked.  I used  darks, flats and bias frames which I have used successfully for other images.  Could it be a processing problem in DSS ?  Has anyone experienced this ?

Thanks for any help 

Cheers

Ian

[carastro]

Was this a one shot colour camera/DSLR?  It seems not to have registered properly in some areas.  Not sure if the coma has anything to do with it, but with a one shot, it should have been able to register evenly.

Carole 

[halli]

Hi Carole

Thanks for your response.

The original DSLR images seem OK they were taken with a modded 1100D.  I did not use a CC

 I have attached one of the lights which I have processed in PI without any calibration

The defect seems to be introduced by DSS.   Its strange that I have never had this problem before.

I thought it may be related to the large number of stars in the field.    I originally had quite a few frames in DSS to stack and the output contained a blank portion in one of the sectors of the image - it clearly couldn't handle the data,   I reduced the number of lights to 4 which resulted in the output posted previously.

[dph1nm]

Try cutting the number of stars DSS detects (using the slider). Remember it only needs 8 stars in common between the frames to stack correctly.

NigelM

[D4N]

You could also try cropping the image before stacking. You use the rectangle tool to draw a box around the bit you actually want (presumably that won't include the wonky stars at the edges). Then tell DSS to just stack that bit. It will be a lot faster and may fix the problem if your lucky

Sent from my iPad using Tapatalk

[halli]

Thanks Nigel and  D4N .  

I have already tried using the slider in DSS to reduce the number of detected stars but to no avail - I will reduce this further if it only needs 8 !

I will also try the cropping approach if this does not work

Feel it must be something to do with the number of stars !

Cheers

Ian

[halli]

Hi again - I eventually found what cured the issue !

I changed the RAW setting in DSS for Bayer matrix  transformation from AHD to Bilinear Interpolatian.

I guess in retrospect it needed to be something to do with the Bayer matrix but why changing the setting as above did the trick is anyone's guess !