Orion Optics 1/10 wave thoughts.....

[Moonshane]

ha ha I just won this 150 mm Dobsonian f11Telescope on eBay (end time 14-Aug-10 15:06:43 BST) on ebay for £114.50. OK it's 'only' a 1/4PV version as far as I can tell from the description but at that price I'll take a punt and see what it's like. I suspect I could get a 6" mirror refigured in due course to 1/8PV or even 1/10PV and coated for maybe £200? even at £289 so at maybe £400 total, it's a bargain I reckon and £200 less than a new one. I'll see how this compares with my refractor and report back - although Russ may jump in first as he's likely to collect it and store it for me until I get down there or he comes up here and he'll no doubt be comparing it (with my blessings of course!) with his 6" f5 version.

cheers

Shane

[johninderby]

Great buy !

Actually you can buy the 6" 1/10PV mirror and secondary brand new from OO for £289.00 and sell the standard set for perhaps £75.00 to £100.00.

http://www.orionoptics.co.uk/OPTICS/opticsultragrade.html

The standard optics are rated as beter than 1/4PV so they're probably about 1/5PV.

John

[mike bacanin]

Mick,

I built a custom 6" F8 planetary newt early this year with OO Ultra Grade optics.

They were better than 1/12th wave on zygo with stunning strehl.

I can say that the planetary performance was very good, with images very close to the TAK FS 128 i owned.

When you get mirrors of this level, the contrast will be excellent, and combined with a small secondary, results in a very capable scope.

Regrettably due to health issues i sold the components.

see this saturn sketch i made with it. cassini just visible at ansae at this low ring tilt.

Whilst 1/4 is ok, there will be a real difference at 1/10th or more, especially with a good ortho used.

Regards

Mike

[Moonshane]

cheers guys

I'll report back when I get a chance to have a look. as you say, it's likely to be better to improve the optics one way or another and maybe OO will accept a trade in as it's one of their mirrors. will be great to compare the current mirror with my larger dob and refractor on moon, planets and doubles before the improvements I plan such as figure and lining the tube with thin foam and flocking.

be interested to hear how Mick gets on if he goes down the 6" f11 1/10PV route.

[michael.h.f.wilkinson]

Just my 2 cents: I used to have a 6" F/8 Newtonian with a 1/8PV mirror, and it was great for planets. I have a C8 now, which beats it on deep sky and general portability, and has a WAY better mount than I cobbled together myself, but on planets I think the Newtonian was a bit crisper than the SCT. The latter has improved with the addition of better EPs (from Plossl to LV to Radian), but I am considering getting a long focal length Newtonian for planets again.

[Moonshane]

hi all

Not 1/10PV but I collected my 6" f11 yesterday. Here's my initial thoughts :

http://stargazerslounge.com/equipment-reviews/112331-orion-optics-uk-6-f11-dobsonian-review.html

If anyone is interested in the standard optics if I do sell them (maybe about £75) then do let me know as I'll keep you in mind as first refusal. Not sure this will happen though.

cheers

Shane

[nicnac]

have you thought about a TAL 150P8?

the TALs use 1/10 wave mirrors

http://www.telescopes.ru/product.html?cat=1∏=14

http://www.teleskopfreunde-bayern.de/tal150r8_large.jpg