Yet another eyepiece question...(sorry!)

[LoveFromGallifrey]

57 minutes ago, Dantooine said:

I’ve seen 5 people get this telescope on here in the last few months. All of them have been very happy with it. One much preferred it over his dob and has posted very detailed observations and has pushed it to its limits.  The list of his observations has blown me away in the very short time he’s had it (jealousy).

I’ve a friend who bought the 80mm version, he does the photos stuff, not my thing at all but has shown me some amazing pictures. The quality and build is just something that will not disappoint. I’ve spend heavily on diagonal, eyepieces and mount for this telescope and truly love it. 

Thank you for this, I really appreciate it. Ofc, everyone is different - but it is reassuring to know other people are happy with the scope considering how limited my own experience is. I will take the leap of faith I think, and buy it - and see how it all works out. If it really doesn't I can always sell up and try again. 

In the meantime, I shall have to get saving every spare penny - gotta get me that new car, so I may even have the space to indulge in two different setups - and new place to live, preferably under darker skies! 

[LoveFromGallifrey]

On 28/10/2020 at 12:35, Second Time Around said:

I agree with your idea of trying out a zoom.  That and a Barlow plus a low power, wide field eyepiece is all you'll need to begin with, and possibly for a very long time.

I've tried out 4 different zooms and kept 2.  These are the Baader 8-24mm that's very good but costly, and the very inexpensive Svbony 7-21mm.  This new Svbony is apparently identical to the Orion E-series but at an even lower price.  The stated eye relief is 16.3 to 18mm.

The Baader is a little better corrected off axis in my f/6 scopes and has a larger field of view than the Svbony.  However the Svbony is much smaller and lighter, and exceptional value for money (about £40 to £45).  I bought the Svbony because of the excellent reviews it had on Cloudy Nights, and am happy to recommend it myself.  

Svbony also sell 8-24 and 10-30mm models, but again I haven't seen these.  Both are much bigger and heavier than the 7-21mm Svbony.  Additionally the 10-30mm has a particularly small apparent field of view, plus only 5 elements and so is unlikely to be as good.

The ones I didn't keep were firstly a Celestron (from a terrestrial scope rather than the usual astro model.  This was because it didn't have a filter thread).  Secondly a clone of the Hyperflex 9-27mm.  There was nothing wrong with the Hyperflex, but both the Baader and the Svbony 7-21mm can be adapted to take a Televue Dioptrx adapter to correct the astigmatism in my eyes.  I gather the astro model of the Celestron 8-24mm has a T thread that a Dioptrx will also fit.

Turning to Barlows, I'd very much recommend a dual 1.5x/2x model on your f/7 as this gives much more flexibility.  These dual models are sold as 2x Barlows, but some 2x models can also be used at 1.5x.  These ones allow the lens cell to be unscrewed from the body of the Barlow and then screwed into the filter thread at the bottom of an eyepiece.  Very often this won't be in the blurb, but on their website the US retailer Agena Astro states whether this can be done or not under the specifications.  I'd also add that the 2x Orion Shorty Barlow that Agena doesn't sell can also be used at 1.5x.

I use the 2x option when atmospheric seeing is good and in conjunction with a 7-21mm zoom will give you magnifications of 68-204x.  However I find that there are many nights in the UK when a 1.5x Barlow gives the maximum that the seeing will allow (153x).  Sure you could use the Barlow at 2x with the zoom set at 9.3mm to get this magnification, but this will give you a smaller field of view.  This because the apparent field of view of nearly all zooms is lower at higher focal lengths.

I've got an Altair 72mm f/6 EDF with a very similar spec to your new scope.  I'm very pleased with mine and am tempted to add the 102mm to the arsenal.  Good luck with yours! 

Dang, somehow I missed replying to this - but thank you so much! This is really helpful advice and I sure do appreciate it.