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#1 BBryce

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Posted 15 March 2013 - 06:39 AM

Hello,

I own a home-made 12" f5 truss tube and I just started to test bino viewing with a maxbright and a couple of 20mm william optics WA 66°. I immediately felt in love and can't go back to mono vision, just outstanding with a 12" !!

I don't use any ocs/oca or barlow,I can observe wide-fields with an oversized secondary mirror (3.1").

I also use a shorter set of fiber carbone tubes for lowering my secondary cage about 4.33" so I can focus without correctors. Deep sky views are breathtaking !

I was wondering if I can put a powermate 2.5x with my lowered secondary cagee. My 20mm will turn to 8mm and then I don't need to buy a new couple of eypieces for observing planets & moon.

But I tried with a standard 2.5x barlow (gso) and it won't work...

Would the Televue Powermate 2.5x fit with my setup ?

Your thoughts ?

Bryce

#2 johnnyha

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Posted 15 March 2013 - 04:31 PM

Possibly, more probably you will need an extension. At 1X though you may very well be getting some loss of aperture.

#3 BBryce

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Posted 16 March 2013 - 01:28 AM

Hi Johnny,

Thanks for your answer, I was thinking about an extender tube too as I do with mono viewing.

But powermate 2.5x + extender tube + maxbright & EP's, my focuser (HC1 kineoptics) will throw in the towel ;) no need to state about collimation too...

So for a higher power with my setup, no other choice but a pair of 10mm ?

Some EP's recommandations around 10mm ?

Cheers,

Clear skies !

Bryce

#4 sopticals

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Posted 16 March 2013 - 02:36 AM

Hi Bryce,

I use the GSO15mm(70deg) Superviews. Previously used the WO20mm(66deg) oculars, which came with my WO binoviewers, but like you, needed a larger image scale, for moon and planets. Now my 20mm WOs stay in the draw. I had tried the GSO15mm Plossls but for some reason had merging problems, and I didnt appreciate the narrower FOV anyway. No problem merging the Superviews. Also tried ES82 11mms but the binos didnt perform as well as with the 15mm SVs.

Stephen.(44deg.S.)

#5 BBryce

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Posted 16 March 2013 - 02:56 AM

Thanks Stephen !

But compared to my WO20mm (66°), a pair of 15mm might be still to low for planets and moon or not ? Too close power ?

As i will purchase a pair of vixen NPL 30,I was more thinking about a higher one, like a pair of vixen nlv 10mm, or Baader classic ortho.

30mm, 20mm, 10mm, good guess ??

Did you meet some merging issues with your pair of ES82 11mm ? The pair seems to be a good value though...

Cheers mate !

Bryce

#6 sopticals

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Posted 17 March 2013 - 01:49 AM

Thanks Stephen !

But compared to my WO20mm (66°), a pair of 15mm might be still to low for planets and moon or not ? Too close power ?

Did you meet some merging issues with your pair of ES82 11mm ? The pair seems to be a good value though...

Cheers mate !

Bryce


Hi Bryce, :cool:

Ok, maybe the image scale dosent increase enough when you are not using an :question: OCA. In my case the GSO 15mm Superviews give approx 285x/475x depending on which dob Im using, whereas the WO 20mm pair give approx 210x/350x, so an appreciable difference. The ES82 11mm pair give approx 380x/580x at which my seeing does not support. Mostly I am happy :bow: at 285x, as seeing at my locality generally supports this, and this image scale is sufficient to reveal clearly the fine planetary/lunar detail I am interested in.

Best regards :jump:
Stephen.(44deg.S.)






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