Orion Optics 6" f11 'Planetary' Dobsonian

[Moonshane]

I wonder how many SGL members have the same scope as me? It seems to be a scarce beast and I'd be interested to see how many other members have the same scope and how highly you rate it? I'll never part with mine.

Cheers

Shane

Here's a pic of mine on my home made equatorial platform

[Matthew]

Nice scope Shane how do the planets look through it ?.Ive never heard of or seen another.

[Moonshane]

Cheers Matthew. It's really good on planets but just shaded I think (not surprisingly really) by my masked off (to unobstructed 170mm so also f11) 16" 1/8PV dob. That said, if the night's looking like a planets and doubles only night I bring out the 6" rather than lugging the 16", especially with the tracking. The 6" has the advantage over a refractor as there's no CA at all at it's a lot easier to mount than say a 6" f8 achro.

[Mike73]

First time I've seen one, looks tidy.

Is that a OO base or did you make it Shane?

Also interesting to see your platform, am I right in saying that you didnt use the Celestron motor for it but used something else? EQ platforms are great for planets and lunar though eh.

[Naemeth]

What eyepieces do you generally use for it, because 60 degrees at 200x is something like 0.3 TFOV, which is rather small, too small for the Moon.

It looks great though, and probably quite light considering the tube length.

[Moonshane]

What eyepieces do you generally use for it, because 60 degrees at 200x is something like 0.3 TFOV, which is rather small, too small for the Moon.

It looks great though, and probably quite light considering the tube length.

Hi Naemeth

I use a wide range of eyepieces :my 32mm TV plossl (full lunar and solar disc fits in nicely with a decent margin). For detailed lunar I like my 12.5mm BGO and for more detail and planets my 10mm/8mm Radian are good. For doubles and extreme liunar when the seeing allows, I use my 6-3mm Nagler zoom, sometimes even down to 3mm for some doubles (533x) and this gives a 0.1 degree field. more than adequate for tight doubles. these higher mags are where the EQP really comes into its own. My most used is the 6mm end of the zoom though at 267x and 0.18 degree field - plenty for many subjects.

First time I've seen one, looks tidy.

Is that a OO base or did you make it Shane?

Also interesting to see your platform, am I right in saying that you didnt use the Celestron motor for it but used something else? EQ platforms are great for planets and lunar though eh.

Hi Mike

It's an original OOUK base and makes for a tall spindly set-up off the shelf. I did a few mods and the EQP makes it all much more bottom heavy and stable. I used a 12v 4 rpm DC motor with a PWM controller. This allows me to get down to about 2 rpm which matches the curve of my platform and location.

[John]

It's a very nice and unusual scope Shane

Ade Ashford (Sky & Telescope, Astronomy Now) reviewed one a while back. He was very impressed:

http://www.nightskie...50L/OD150L.html

Having owned the scope he compared the OO 150L to, the Intes MN61, I can understand just how good the OO is - the Intes was superb

Maybe it's time the long focus newtonian had a resurgence in popularity in the same way that long focus achromat refractors are at the moment.

[Moonshane]

I agree John. For me (I am strictly a Newt man) there's not much (assuming similar apertures) that can touch a good quality slow newt on most subjects.

[Naemeth]

I suppose they are probably cheaper to make than the average apo or achro with a similar aperture. Of course, it falls at imaging, but then we all know this is inevitable. This is the slowest Dobsonian (unmodded) I've seen, do any slower Dobs exist?

[paul mc c]

Dont have one,but the fella i bought my 12'' Orion Optics off had a 6'' and an 8'' Orion optics,all research grade optics.The 6'' was the one that he said he would

never part with,not only for the planetary views but because it was so easy for him to move and set up.

Lovely scope.

[umadog]

I'd like to look through a scope like that some time.

[nightfisher]

Much as i prefer refractors, i can really see the advantage of a very long focal length dob over a long frac

[AlexB67]

Hoooo, Nice scope Shane. I was doing some research on something like the optimal newt for size and use, focal ratio etc to split doubles, and somehow ended up here. This should work fairly nicely in that department too an 8 - 10 inch in that ratio would be a beast, and that with a close to aplanatic mirror would make an awesome scope for double star work. They don't exist as far as I know in the sky-watcher range, not mass produced afaik. Another market there perhaps to be explored as they could still be cheaper than alternatives .. I think

[Moonshane]

cheers! it's a great scope which I think I'll keep forever. yeah, a 10" f11 would be maybe 8.5 feet tall at the eyepiece. I think OOUK do a 10" f6.4 on request and they do come up for sale every now and again. they are also quite tall and spindly though and I have heard of at least one that's gone over. ways around that though of course.

[Moonshane]

I have sold some books and finally bitten the bullet with a three vane curved spider from Destiny in the states. Just ordered it for £60 delivered although I'll presumably also get stung for duty etc. Hopefully this will create even more sublime views. Ade Ashford seemed to like this upgrade too.

[John]

I will be very interested to hear how the change of secondary support pattern affects the images of various objects Shane  

[Moonshane]

cheers John - me too. I'll certainly report back. With this being my double star scope and also Jupiter/Mars moving into good positions over the next month or so it's a great time to do it I think.

[nightfisher]

good luck with it, should improve  a cracking scope

[chiltonstar]

Now that looks like a real telescope......

Chris

[estwing]

well I've finally got my mask finished and at 170mm it gives me F11.1 so watch out Jupiter I'm comin to get ya'!

[Peter Drew]

I have a 4 aperture mask for my 30@ mirror operating at 12" F10, 10" F12, 8" F15 and 6" F20, as soon as the telescope is up and running again I'll give it a try and report back. 

[Moonshane]

My new spider arrived and I fitted it today. a straight forward affair as I reused my existing secondary stalk and with a bit of tweaking the depth of the secondary position was the same as currently. three holes drilled and an hour or so putting back together, gluing loose flocking etc etc and it's done.

my first quick test was on a very low Venus, just above the rooftops with a warm scope and very windy conditions and wow. I am very impressed. possibly the best views I have ever had of a lovely crescent.

I am looking forward to getting a look at Jupiter and some doubles later if the wind dies down a bit.

I will do a few notes and a bit of a write up later,

[John]

This is the curved vane one isn't it Shane ?

Sounds very promising 

[Moonshane]

indeed John, the three vane job. Venus was very nice with no spikes at all. impressive. hopefully I'll be back out later, Jupiter and a couple of tighter doubles will be a test. maybe I'll even finally split Sirius....

[estwing]

Good luck..