I have thought about a rainbow filter myself, to play with for fun; dont know how realistic they look but sounds like fun anyway. Star filters come in various point values, usually 8,16 etc, and can produce great and not great effects. So like you say in moderation. IMO it deepens in the size and distance of the subject, a big streetlamp may give off big wide bands of light which might not look right; bur from further away will probably look pretty cool. In some conditions (like your image) you will get subtle staring just with the lens, this may also be affected by the amount of diaphragm blades that control the aperture (speculation) I have got a sunset filter, but have never really got it to look right, it always seems OTT on the colours, that maybe partly the filter colour and partly user error (more speculation) Some cool/not cool star examples! http://www.renderosity.com/viewed.ez?galleryid=846677&Start=109&Artist=LostPatrol&ByArtist=Yes http://www.renderosity.com/viewed.ez?galleryid=846677&Start=109&Artist=LostPatrol&ByArtist=Yes http://www.renderosity.com/viewed.ez?galleryid=932097&Start=37&Artist=LostPatrol&ByArtist=Yes http://www.renderosity.com/viewed.ez?galleryid=931001&Start=37&Artist=LostPatrol&ByArtist=Yes

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