This scope comes to my mind after the Borg 101ED, why? It's cheap! But another big attraction is the weight! Guess what, it's just 7-7.5lb as listed from different websites! It's about the same weight with the Borg 101ED therefore.
It's f/9, but for my application, it's even better than f/6.x for the Borg for f/9 must work with my PST etalon. f/6.x could be a little bit difficult. For wide field application, it comes with 2" focuser which is definitely better than my C5.
When comparing with the C5, the weight is so similar, so all my mounts (except that TG-SP II, but that one won't work well for the C5) are going to work. It delivers wider field of view, similar light gathering power despite lower resolution due to the smaller aperture. And I guess when I sell my C5, I got nearly enough money to cover a 2nd hand Orion 100ED, very fine for me.
It gives 2.9 degrees field of view with my Pentax 40mm SMC XL which is even close to my Ranger (3.3 degrees maximum with 1.25" focuser), and for high power, it should be even more contrasty as a refractor.
If portability is concerned, the weight alone should make it similar with my C5 but of course, it's much longer.
Minor point includes that it's front cap aperture stop is 52mm, a perfect fit with my Solarmax 40, and if I could motorize the focuser, I could even sell my Borg 45ED II.
Right now I saw a good deal, I would wait to see if there's any better deal, that also gives me time to cool down and to think twice about this idea.
I guess I will take the plunge, the shipping cost should be acceptable at around $60 USD only and my current paypal balance should be enough to pay it. I dare not to withdraw money from paypal for their exchange rate is too much discounted, so to use it for purchasing seems a smarter choice.
I will try it out with my PST etalon, as well as with my Herschel wedge. If it works out nicely, I will sell my C5 and that could give me back at least 2/3 the amount which I have paid. If it does not work out well, it makes little harm to re-sell it locally.
Actually, I suspect that it will work far better, as there's no secondary mirror to give that internal reflection! And the possibility to be able to use it with my Herschel wedge is really attractive. The wide field capability due to the shorter focal length (900mm vs. 1250) and the 2" focuser vs. the 1.5" rear openning is also great!
At the time being, I will still try to motorize the focuser of my C5. In case it works, maybe I can ask for a little bit more money when selling it.
Payment just sent, my paypal account has more balance than to cover it, the expected time for delivery is less than 10 days. Really longing for the new member.
I'm now worrying if it's too long that it would be hard to use in an indoor setting? Anyway, got to check.