Ultimate planetary scope for a HEM15

[michael.h.f.wilkinson]

The C9.25 is around 9.4 kg, the mount will need a counterweight, but it should still fall well within the limits of the HEM15. I have seen plenty of sparkle in star clusters (especially globulars) with my C8. They are sensitive to collimation, but tend to hold collimation well. The MN190 mentioned earlier is 12.5 kg, or thereabouts, which is probably too much, especially when cameras or EPs are added. 

[Ags]

Yes, I thought the MN190 would be a bit much. If I could add a handle, the C9.25 would be a contender.

On reflection, I may keep the C6 for photographic duties. When the HEM15 arrives I will try it out through galaxy season. Instead I may sell my 90 mm refractor to fund the CC8. I find I am more happy taking the much lighter ZS66 out for grab and go sessions, so maybe the 90 mm was a case of aperture fever… I should have saved a bit longer and got an FC76DCU…

[michael.h.f.wilkinson]

10 hours ago, Ags said:

Yes, I thought the MN190 would be a bit much. If I could add a handle, the C9.25 would be a contender.

On reflection, I may keep the C6 for photographic duties. When the HEM15 arrives I will try it out through galaxy season. Instead I may sell my 90 mm refractor to fund the CC8. I find I am more happy taking the much lighter ZS66 out for grab and go sessions, so maybe the 90 mm was a case of aperture fever… I should have saved a bit longer and got an FC76DCU…

For really extreme portability, there's this, of course:

😉 Works well on lunar imaging, hope to test it on white light solar soon. Downside: only 62.5 mm aperture, but a decent FOV to capture the corona, should I be lucky with the weather on April 8

[John]

I read somewhere that the very early versions of the MN190 had a secondary diameter of 51mm which, at 27% of the primary diameter, made it potentially a decent visual planetary scope. Quite quickly though Skywatcher decided to put a 63mm diameter secondary in them (33% of primary diameter) to suit the needs of imagers better but perhaps moving it away from an optimal visual planetary scope ?

The Russian mak-newts I mentioned earlier in this thread are optimised for high resolution visual observing with secondaries of around 20% or even less, than the primary. They are still heavy instruments though, take time to cool, and have their quirks so I'm guessing that your considerations have moved on now 🙂

Edited January 23 by John

[Mr Spock]

I see the C9.25 is now £2995  I bought mine new for £900...

For me the Askar 140mm triplet at £2098 looks a bargain and just under the weight of the C9.25.

[johnturley]

2 minutes ago, Mr Spock said:

I see the C9.25 is now £2995  I bought mine new for £900...

 

That's for the Edge HD version, the standard XLT version is £1,895.

John 

[JeremyS]

And for visual, which I think was Ags main focus, the XLT is fine

[Ags]

I am still finding new ways of being indecisive, having narrowed the choice down to 1 scope, the CC8, I think I have come up with a cheaper and probably optically better option. How about the Orion Optics VX8L? It weighs 8kg, so it fits in the weight budget, and if it is upgraded to 1/10 PV option it comes to about 840 euros... It would beat the CC8 on actual aperture, be about the same weight (but a lot longer), and have a much smaller secondary. Obvious drawbacks are it would be very wind-affected, and visual use is a non-starter on an EQ mount. The VX8 is also a possibility - the secondary is still smaller than the CC8 and it is a kilo lighter. It will be a little easier to mount and a little less vulnerable to wind, but collimation at f4.5 (vs f6) would be more fiddly.

I used to have a 150pds that put up very nice images of Jupiter but sadly I didn't have the right mount for it, so I know a simple newtonian can do very well... The two things that go against either the VX8 or VX8L are (1) Orion Optics UK's reputation, and (2) I really think newts on EQs are unsuitable for visual use. However for visual use I can set it up on an alt-az mount like a skytee.

[davidc135]

If the Orion Optics VX8L upgrade is truly 1/10 pv and smooth I don't see it being easily bettered visually on the moon and planets.  David