Next mini project...

[RobertM]

I've got a bit fed up with the flaring I get off bright stars with the Hyperstar system so I'm going to attempt to blacken the edges of the lenses.  That should, in theory, remove nearly all of the internal reflections causing those issues and allow me to image fields with stars brighter than about Mag 5-6

All I need to do is find is some matt finish flat carbon black paint that's also waterproof

The nearest I've found so far is this:



Still looking though...

Robert

[MarkS]

What flaring do you mean?  Do you have an example? And how do do know the cause?

Mark

[mickw]

Are you going to be painting the glass ?

Are the edges of the lenses simply ground (frosted) ?  If they are polished (clear) I think the painted edge would behave like a mirror.


Rustins Blackboard Paint might be the paint you're looking for, or Humbrol Matt Black from a model shop

[Rocket Pooch]

Hi Robert,

You might like to try Krylon ultra flat black, I used this on my tube and secondary mirror edges.

http://www.backyardvoyager.com/sctflock.html

[RobertM]

Mark, these are the strange artifacts that I've seen on images with bright stars.  The artifact seems to be on almost the opposite side of the image to a bright star.  Others have had success in reducing those by blackening the edges of the Hyperstar lenses.  Those lenses are quite thick and have a largish edge area so combined with incident angle of light through the HS that makes sense to me.

Mick, yes those edges are frosted but you're right about producing a mirror - not the best thing to do to.  I also noticed that the internal anodising is nowhere near as black as it should be and there are a couple of scratches where bare metal is showing through so those are other candidates for blackening along with the secondary baffle.

Thanks Chris, the Krylon ultra was another I've been looking at.

Robert