The Ghostly Tower - AG12

[gregbradley]

I see.

Your Astronomiks are they the latest Generation of AR coated filters or the earlier ones? (which were pretty good compared to the mirrored type filters like Astrodons and Baaders).

Greg.

[strongmanmike (Michael)]

Originally Posted by gregbradley

I see.

Your Astronomiks are they the latest Generation of AR coated filters or the earlier ones? (which were pretty good compared to the mirrored type filters like Astrodons and Baaders).

Greg.

They are the latest low reflection variety, as I said with the Starfire and 4" flattener and the 16803 and testing on Alnitak the Lum and Ha were virtually halo free, the RGB not so, this seems to have been reversed with the AG12...?

I plan to do a more diffinitive test tonight just to check what I am getting exactly.

Mike

[gregbradley]

One simple thing you could try is to make a mask for the Proline's CCD window. A bit of black cardboard that Newsagents sell for kids school projects. Cut out an opening the same size as the chip and tape it over the window. The Apogee camera had a professionally made black alumiunium mask like this they sent me to retrofit to reduce reflections.

I think it helped. Not a perfect fix but a simple one and it may help (it also may do nothing!).

Greg.

[strongmanmike (Michael)]

Originally Posted by gregbradley

One simple thing you could try is to make a mask for the Proline's CCD window. A bit of black cardboard that Newsagents sell for kids school projects. Cut out an opening the same size as the chip and tape it over the window. The Apogee camera had a professionally made black alumiunium mask like this they sent me to retrofit to reduce reflections.

I think it helped. Not a perfect fix but a simple one and it may help (it also may do nothing!).

Greg.

Doesn't make sense how that would affect halos though.. spurious off axis reflections perhaps but not halos, halos result from direct back and forth reflections as far as I am aware and a mask would do nothing to mitigate these...would it

My Proline 16803 does have the chip mask

Mike

[gregbradley]

Yeah you're right there. It'd be between the filters and the corrector.

I don't see any with the CDK beyond usual and that also has a corrector.

So I imagine the right combo will get rid of those halos.
Its one reason I switched from Baader to Astrodon Gen 11 filters. They seem to be a big improvement on reflections.

Greg.

[Peter Ward]

London to a brick the halos are an artifact of the field corrector.

Take a pic without the corrector...... Might be a little ugly at the edges....

[Jen]

very nice Mike

[renormalised (Carl)]

Can't remember if I commented earlier on this pic, but anyway, nice shot, Mike. "The Ghostly Tower" sounds like an episode of Harry Potter!!!