mirror cost

How can an entire meade Lightbridge 16" cost only £1299 here

but a 16" primary on its own is a min of £1699 here

what is considered a good price for a 16" mirror of decent quality?

fguihen wrote:

what is considered a good price for a 16" mirror of decent quality?

Ultra-low expansion glass, then the type of coating. Most top quality coatings offer in the region of 96%+ reflectivity. Whereas the type of glass used must be able to withstand changes in temperature. In the 80's and 90's pyrex was among the best glass to use for affordability to amateurs and ultra low expansion. I am sure this has changed with technologies, but as I am an old school telescope maker, I don't know what that new product is.

Seanie.

Fintan,

As Seanie outlined, its down to quality. The big boys like Meade and Celestron mass produce mirros made by machines. Although these are good mirrors, they are not nearly as good as hand figured optics made from high quality materials and high reflectivity coatings. If you compare the two mirrors side by side you will see the difference. Also you will never get a 'lemon' from orion. The other factor to consider is focal length. Although it may not seem much there is a significant difference in the amount of work necessary to produce an f/4 mirror over an f4.5 one.

If you are looking to build a scope, I did see a very good offer from telescope-service;

1098E for a 16" mirror, secondary, and crayford focuser. www.telescope-service.com/ATM/optics.html
I would also add that to be fair Orion Optics (UK) do make very good optics. My own 10" is an Orion mirror and it really is first rate.

I have a 16" mirror set going a begging - new and unused. I was asking €1300 for it last year, but seeing the recent prices posted here, I'll let it go for €1000 if you twist my arm. Otherwise I'll just find a use for it at some stage.

Phil.

fguihen wrote:

How can an entire meade Lightbridge 16" cost only £1299 here

but a 16" primary on its own is a min of £1699 here

what is considered a good price for a 16" mirror of decent quality?

Fintan,

A fairer comparison would be between the Lightbridge 16" made by GSO and this GSO Mirror from Teleskop service which would be the same mirror.

In this fairer comparison the €800 differential pays for the rest of the scope. The Primary is always the most expensive single part of a dob. That holds for cheap chinese scopes as well as the Premiums. ie, in the case of an Obsession Dob for instance the Primary is probably closer to 3/4 of the total cost of the scope to build!!

TBH though. Beginners like you and me probably don't have the expert eyes yet of the likes of Dave or Philip and probably couldn't tell the difference between premium optics and 'Just OK' chinese mass produced optics most nights. I just wonder is it worth going to the expense of premium optics for your first atm build. ie why go to that expense when the likes of our beginner eyes will not really notice much difference when you will no doubt want to upgrade in apeture and bigger mirror for your next even better atm build in a few years at which time you will have the eyes to appreciate a premium mirror.

All that being said Philip might be offering the best of both worlds. Premium optics for a near mass produced price!!

completely agree Keith, im sure my eyes wouldnt see any difference between a 2500 euro primary anad a 1000 euro primary. as id be getting a lightbridge anyway if purchasing a scope, id be getting a mass produced mirror anyway.

Im still working on a design that I am happy with, rather than just pulling plans from the web or a book. It would be real nice to have a scope that you are almost totally happy with as you have added all the features you want ( within budget of course).

Never considered the 800 difference being used for the scope parts but I think also with the 800 quid i could get most of the tools required and all parts.