GSO Primary Mirrors

[Astralstroll]

When i am in one of those dreamy moments, I ponder getting a Sumerian Optics 16" dob. However, having just checked their website, they are no longer supplying the GSO mirrors directly, but are asking the purchaser to supply the GSO mirror. This has set me thinking.

How good are the GSO primary mirrors? A quick trawl on the internet has shown them to be significantly lower cost than other mirrors of the same size.

Are there any good alternatives to GSO at a comparable cost?

Dave.

[laser_jock99]

The GSO mirrors are good value (I have two fitted in Revelation Astro Scopes). My understanding from reading around on the net is that there was an issue with the coating not last long on some larger diameter mirrors but I believe that issued has been solved with a better (thicker?) SiO2 protective layer. I'm keeping a close eye on mine for signs of deterioration but nothing untoward seen so far.

I don't know who sells GSO mirror sets though, or of any (cheaper) alternatives.

[John]

The only GSO mirror I've used was in a Meade Lightbridge 12". The Lightbridge, Revelation and Telescope Services (TS) dobsonians use GSO optics so reviews of those scopes will give you some idea. I felt my Lightbridge 12" was about as good as the Skywatcher equivalent optically although the coatings were showing some signs of deterioration for their age. New GSO mirrors probably have better coatings though.

[Mike73]

GSO mirrors vary in quality because they arent tested (I've heard the same about the OOUK 1/4Pv), you may get a really bad one like I initially had or you may get a good one alot closer to 1/6Pv, its pot luck what you actually get when it comes to quality (but thats the same as any Meade reflector as they use GSO's).

For the price I think GSO's are very good value and luckily you dont hear of too many bad mirrors.

I think the most important thing to keep in mind is buying a mirror thats been tested so you actually know what you are getting.

My GSO mirror report below.

[ronin]

Galvoptics advertise a 16" f/5 at £942, what I cannot see is a faster one the f/5 which is a little odd.

Galvoptics

Oldhame Optics is another:

Oldham

For Oldham select the Price list option on the left hand side, they are somewhat more expensive then Galvoptics.

Was it 16" that you are intending to get or is it still a bit of a wish list item?

[Astralstroll]

The 16" is my ideal size. I think anything much smaller and I will want to upgrader again in the future, and anything larger will be both more expensive (most likely considerably) and also less transportable.

Dave.

[E621Keith]

Galvoptics advertise a 16" f/5 at £942, what I cannot see is a faster one the f/5 which is a little odd.

Galvoptics

Oldhame Optics is another:

Oldham

For Oldham select the Price list option on the left hand side, they are somewhat more expensive then Galvoptics.

Was it 16" that you are intending to get or is it still a bit of a wish list item?

I have a feeing Galvoptics' price list may be seriously out of date. The price for their mirrors are significantly lower than today's market average for European mirrors.

[ronin]

Was thinking it as well but all I had to go on was their site.

Actually thought I read/heard that they were not doing mirrors any more, something alone those lines maybe not silvering.

[crashtestdummy]

Also have a look at nichol optical as thats who im planning on using when i build my next scope.

[ronin]

Thanks for Nichol Optical, now bookmarked.

[cs1cjc]

There is a test of two GSO mirrors here: http://translate.googleusercontent.com/translate_c?depth=1&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=de&tl=en&u=http://www.astro-foren.de/showthread.php%3F9274-Die-neuen-GSO-16-Z%25F6ller-im-Vergleich%26p%3D35463&usg=ALkJrhhsc8qJhaGFYx6vwl7u2Qc45Fq5eg#post35463

Orion Optics standard mirror sets (1/4 pv wavefront) do not include a user test certificate, but this is not the same as not having been tested, I think.

[estwing]

Also have a look at nichol optical as thats who im planning on using when i build my next scope.

+1 for Nichol optics..i've been dealing with John over the last couple of weeks..fantastic bloke nothing is too much trouble

[Damo636]

There is a test of two GSO mirrors here: http://translate.googleusercontent.com/translate_c?depth=1&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=de&tl=en&u=http://www.astro-foren.de/showthread.php%3F9274-Die-neuen-GSO-16-Z%25F6ller-im-Vergleich%26p%3D35463&usg=ALkJrhhsc8qJhaGFYx6vwl7u2Qc45Fq5eg#post35463

Orion Optics standard mirror sets (1/4 pv wavefront) do not include a user test certificate, but this is not the same as not having been tested, I think.

Reading between the lines, I,m guessing both these mirrors were pretty good?