NGC6603 in M24 the small Sagittarius star cloud

[5ash]

This was taken last night through my SW120ED / 0.8x reducer / nightscape camera. consists of 30 X3min subs, darks ,biases & flats. The faint (Mag +11.1 ) cluster NGC6603 is in the centre of the picture.second picture is a crop of the centre of the field to show it more clearly.
regards philip

[raymo]

The wide field is very nice, but in the cropped version all the stars are split into two or more vertical parts. I've never seen that before.
raymo

[5ash]

Hi Raymo ,
You really have to magnify the crop to see that . I think that can be fixed In PS easily, if it were necessary. It's only under very high magnification on small stars that it shows. Not sure that it is still apparent at full resolution, will check.
Regards philip

[5ash]

I have looked at the original and only the blocky pixels are apparent at high magnification.seems to be an artifact of downsizing and then magnifying the image .Have applied the smallest median filter and then sharpened edges to see if the result is better when downsized by IIS transfer.

[raymo]

It's gone now, but I can see it clearly in the cluster itself in the first crop that you posted. I went to post a pic the other day, but it ended up a mess after downsizing.
raymo