henrylr

Seems almost all of the 4.5" mirrors are spherical and are made in China. Now I don't want to buy a pig in a poke so I sent emails to several Chinese makers/sellers asking for strehl ratio and wavefront spec.s. Replies were all the same..."do not have those specifications". Now the mirrors I inquired about were not cheap, selling for $100 to $150. It strikes me as odd that folks would spend that much without any spec.s.

Thanks again. I'm 75 years old and don't do much viewing but thought it would be a fun diversion to improve the old Meade. Robert Royce has retired.

Thanks for the reply. I recently sold my custom made 10" newt. It had excellent mirrors. So that is why I want to improve the optics in the Meade. My other concern is the surface quality of 40-60 for A/8 mirrors available. Another question I have is would you know where I could get a good 4.5" parabolic mirror. The ones from china don't provide any info like strehl ratio and wavefront RMS. Thanks, henrylr

I'm trying to improve the performance of my Meade 4500 and have sent emails to some makers asking for spec.s of their 4.5" primaries. While waiting for replies I started thinking about the secondary. I imagine the stock secondary is, at best, an A/8. So would replacing the secondary with an A/30 secondary result in a visible improvement? The calculation, for a secondary minimum minor dia., result is 1.13" I did check out Edmunds and they have a perfect size for the meade but it is A/8 and the surface quality is only 40-60 which is considered a low quality rating and will likely produce some scattered light. The smallest A/30 secondaries have a minor of 1.3". Would that work or would it block to much light? Thanks, henrylr