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By Roger Corbett
I'm becoming a bit of a Moon and Planets visual observer and in consequence, I'm considering an Amici Diagonal. I have read that at high magnification your view can be obscured. That said, I have read that it is of little consequence when using a Mak and a decent diagonal like this one - https://tinyurl.com/y75z4n5v from Baader Planetarium. I'm really keen to make my East East and my West West. Any advice or experience would be welcome
It figures! First clear night in ages and the pollen is as thick as..well, something really thick. Up to now, I have been fairly careful to avoid dust getting down the tube, but pollen is going to be unavoidable for the next several weeks.
So...what does one do? Are there some do and don't things I should be aware of? It looks like my mirror comes out fairly easy (SkyWatcher 10" ). I'm guessing "chuck into the dish washer on the pot scrubber setting" is probably a really bad idea.
What then, is the plan? What chemicals/detergents should be used...or maybe all chemicals should be avoided? Is it a no-touch surface? Is there perhaps some magic spray that one uses? I do have a can of electronics air that I plan to use from a safe distance to persuade away loose pollen, and that may be enough for the present.
By Geordie mc
LaserColli mkiii in good condition. Makes keeping your Newtonian scope aligned very easy. Comes still boxed. Only selling as I’m selling my scope and won’t need it. It takes 3 small button cell hearing aid type batteries. The existing ones are flat so you’ll need new ones. Some very small marks on the barrel as seen in picture which make no difference to its operation. I don’t have the instructions but I’m sure they will be online somewhere. If I find them I’ll include. I think these units go for around £85-£90 new. Happy to take £55 inc. postage from France. PayPal only please.
I am thinking on grinding my own lightweight mirror (first f4 16", later f4 24"). The lightest and cheapest option is to get a thin blank and slump it in a decent kiln.
Anyone has longer term experiene with slumped mirrors? Overall doesn't seem to be more work than a normal (not pregenerated) blank.
Do I have to grind the backside as in case of normal flat back mirrors to avoid astigmatism? How do people support a convex back while grinding? Does it make sense to grind a hole in the middle for additional support? I am remotely considering a convertible Newtonian/Cassegrain system anyway...