John

The Moonlite on my dob is black too but the ones on my refractors are red !

Whatever the colour they are fine focusers !

Edit: apologies - I mentioned the "r" word in a dob thread

16 minutes ago, popeye85 said:

Remember though that the first link that John posted up refers to Ursa MINOR. Not the big dipper.

Indeed. Thats the constellation that I most regularly use to estimate my NELM.

Here is some info on working out Naked Eye Limiting Magnitude (NELM) using stars in Ursa Minor:

https://darkskydiary.wordpress.com/2012/01/20/naked-eye-limiting-magnitude-assessing-sky-brightness/

Here is another link which gives you a much wider choice of constellations and stars to use:

http://obs.nineplanets.org/lm/rjm.html

Very nice

I too use T2 spacers with my Baader Zeiss prism. I find the 7.5mm and 15mm useful in different ways. I have the 7.5mm on the bottom of the Baader 1.25" twist lock adapter to ensure that eyepiece barrels (especially the 2-4mm Nagler zoom ) don't contact the prism and also use the 15mm on the 2" barrel when I have a 2" eyepiece adapter on the prism to ensure that the edge of the 2" adapter clears the drawtube of the scope.

The Nirvanas / UWANs are pretty good - about on par with the ES 82's I'd say. I used the 4mm Nirvana for quite some time as a high power eyepiece and it did very well in that role.

Your mini-Ercole looks great. My Tak FC100DL rides on a Giro II head on a hardwood tripod. Steady yet very portable

Markus at APM has told me that since they were launched in 2005 there have been 109 130mm F/9.2 LZOS triplets made. 5 more will be made before production of the objectives ceases in 2017. Mine is #20

Mind you there have been a lot more of the F/6 version made - they are more useful for imagers.

I'm looking forward to your 1st light report Gavster

Looks wonderful

700+ units seems quite a lot for a high end scope like that. How long has it been in production ?

10 minutes ago, Chris Lock said:

Wow! very nice Gavster, I know Olly really rates his  I don't know about anyone else? but if you get the chance I'd love a pic of the big bit of glass at the front

With some of these ED glasses and the excellent coatings that can be tricky - the glass can do a sort of dissapearing act from some angles !

Lovely scope Gavster

@Nightfisher / Jules: Thats a great looking ED120 setup. The EQ5 on what looks like the 2" steel tripod should be well up to the task

1 minute ago, alanjgreen said:

The 1.25 inch visual back blocks several mm (.75 inch) of the (hole diameter) light path from the SCT tube to the eye, this must have some sort of "light reduction" effect

 

I don't think it does otherwise no SCT would be able to perform to the resolution limits of their aperture when using with 1.25" accessories, which they clearly do, or at least all the ones that I've owned have.

I don't think 2" eyepieces let in any more light and reveal any more detail. The additional field width can be useful / nice for framing larger DSO's though.

8 minutes ago, Itabot said:

Will this diagonal SCT fit, take 2" EP's without the requiring a seperate 2" visual back?  on a Celestron Nexstar SE8 or have I got it wrong?

http://www.rothervalleyoptics.co.uk/altair-astro-lightwave-2-dielectric-diagonal-sct-fit.htm

 

Yes, you screw the diagonal onto the rear port of the scope in place of the visual back.

You just need to make sure that the larger diagonal will clear the mount when the scope is pointing upwards.

Excellent Jules - I'm very pleased for you

11 minutes ago, DRT said:

Very interesting, John. I haven't seen that style of mounting before. I wonder if anyone still makes them?

These people in the USA do them Derek:

http://www.destinycomp.com/Online store menu.htm

I don't know if there are any UK / EU sources ?

1 hour ago, DRT said:

That's a very interesting secondary mount, @John. Was that fitted by OOUK or is it your own creation? What is the effect on the star images?

It's a OO fitted one. Back in 2006 when the scope was made it was an option but OO don't do them now. The effect on images is that you don't see diffraction spikes. Diffraction is still happening of course but it's dissipated across the whole field. They were fitted when I got the scope but it's performed very well for me so I'm happy with them

As far as I can detect the dissipated diffraction does not cause a lighter background sky but I guess I would need to be able to compare my scope "back to back" with one of the same spec with conventional secondary vanes to be sure.

I'm sure your views will be at least as good as mine, maybe a tad better if your coatings are new. My primary was re-coated and re-Hiluxed in 2010 by OO.

I've had nice views of Venus, Mars and Neptune so far this evening - I have a feeling that it's going to be a good one

Some new pics of my 12" F/5.3 Orion Optics dob because it's out cooling under a clear sky

I'm not sure that the XLT coatings will make much difference but the slower focal ratio will make quite a difference to the amount of CA showing:

Nice !. I like the dark blue / white colour scheme

It will be interesting to compare the Omni 120 with your Startravel 120.

27 minutes ago, MattJenko said:

HI Rob,

It does weigh a bit. I could have used 2 counterweights and the extension, but it seems more pleasing to keep it compact with 3 for some reason...

It might reduce vibrations a bit as well. I've often thought that having less weight but further from the central axis of the mount (ie: towards the end of the C/W bar) creates a rig that is more prone to vibration than having more weight closer to the central axis.

Great looking setup !

I used a Prinz refractor just like that to observe Jupiter in the mid 1970's. I borrowed the scope from a mate and spent each clear night for around a month observing and drawing Jupiter. Towards the end of that period I was getting lots of detail even for a 2.4 inch scope. Amazing what you can achieve when you are broke but really hungry for the hobby

I must dig my old Tasco 60mm F/13.3 frac out and give it some light. Mine is a 1960's scope complete with wooden box. I recall when it's put on a steady mount and has a half decent eyepiece in it, the views are pretty sharp

Matt - what a great collection of oculars and other things, and so neatly presented

I don't see any compromises at all in there - all top drawer !

Super Tak setup Matt

4" and 5" are great apertures for fracs - I seem to have arrived at similar apertures myself !

12 minutes ago, nightfisher said:

I would appear that i will be getting a frac in about a weeks time, but it pails into insignificance compared to the above

A frac is a frac Jules and welcome in this thread

Is it a secret or have I missed a post elsewhere on your forthcoming arrival ?

A foot in both the ES and TV camps Dave - very nice cases !

Oops - I nearly missed the Baaders - thats 3 feet !

Very Nice Mark !

I expect some folks will wonder why others are parting with £1.5-£2 K for a 3.9" scope. I guess we need to take a leaf out of Mike's book and report what we see through them as often as we can to explain

Wow !!!

Put a quality 4" scope in the hands of a skilled observer and look what happens !!!

I've used Powermates with my Ethos eyepieces. They produce the equivilent of the shorter length but don't add any other side effects apart from their weight.

I've also used an Antares 1.6x 2" barlow and a Meade 2" 2x Telextender in the same role. The results were good but the Powermate is the best solution that I have used.

There are a couple of other top end focal extender options including the Astro Physics Barcon and something from Zeiss (I think) but these are hard to find and I've not used them.