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Posts Made By: Jean-Marc Gélineau

January 8, 2003 05:14 PM Forum: Equipment Talk

Vigneting with 2X/3X barlow

Posted By Jean-Marc Gélineau
I have a Skywatcher 10'' dobson and I'm looking for the ''best'' low-cost eyepiece collection. I already have the Televue 25mm and 32mm plössl and I was planning to buy the 20 and the 15 plus a 3X barlow (all televue) (so my ''collection would be 32 / 25 / 20 / 15 / 11 / 8.5 / 7 / 5mm) but I have read that barlows causes vigneting when used with some EP with long focal lenght.

Anyone has experience with barlow?

Thanks

Jean-Marc

January 17, 2003 07:35 PM Forum: Deep Sky Observing

Deep-sky observing under full moon

Posted By Jean-Marc Gélineau
Hi!

I think common sense would probably suggest to look for the brighter and (perhaps) the more compact objects, but did anyone knows if there exist on the web (or in print) some list(s) of deep sky objects observable at (or near) full moon? Any hints or particular observing techniques? I have a Orion Starmax127 (5'' f12) Maksutov-Cassegrain and a 10'' Dobsonian f4.7, OIII and Ultrablock (narrowband) filters. Which scope is better? which filter? in this ''anti deep-sky'' environment...

Thanks

January 19, 2003 04:28 PM Forum: Equipment Talk

Diagonal for StarMax127 M-C

Posted By Jean-Marc Gélineau
Does anyone knows if diagonals for the big Meade and Celestron Schmidt-Cassegrains telescopes would fit on an Orion StarMax127 (5'') Maksutov-Cassegrain? Can I put a 2'' diagonal - a Maxbrite or an Everbrite would be nice - on a StarMax127? I would want to use a Televue 55mm Plossl on it - that would give 28X and a 4.5 mm eye pupil (and a wider field) - now I'm limited to 32mm.

Thanks

January 7, 2003 01:36 PM Forum: Equipment Talk

Threaded Reticles ??

Posted By Jean-Marc Gélineau
I have the same problem with my Antares finderscope - plus I have examined two others Antares finders it was also impossible to achieve focus on a star and the reticle at the same time. It seems it's a ''feature'' of the EPs that come with Antares finders. Anyway, it's not a very good EP.
I have bought a screw-in metal filter-type ring with a laser-etched glass reticle from Mike Spicer, a member of Astromart (see ad at http://www.astromart.com/viewad.asp?cid=165236). Beware, however, that this reticle causes a lot of vigneting in my Celestron 26mm plossl. See photos.

Jean-Marc Gélineau

January 9, 2003 10:30 PM Forum: Equipment Talk

Vigneting with 2X/3X barlow

Posted By Jean-Marc Gélineau
Thanks to all for the answers.
The problem, I think, is that - in my neophyte's naivete - I was mistaken in thinking that a barlow was a sort of ''Eyepice collection doubler'' when in fact a barlow is designed to be used with short f.l. eyepieces to achieve high power while keeping a good eye relief. It can be used to ''double'' an eyepiece collection, but there are tradeoffs.

January 17, 2003 11:34 PM Forum: Deep Sky Observing

Deep-sky observing under full moon

Posted By Jean-Marc Gélineau
Thanks to all for the replies. I think I will concentrate on double stars and planets for now. It is minus 18 deg (Celsius, about 0 Far.) tonight here in Montreal region. Hope my eyes won't stick on these very short eye relief 5,5mm and 4mm Plossl...

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