Re: best goto type mount for SPC8?

From: Roger Hamlett (rogerspamignored_at_ttelmah.demon.co.uk)
Date: 02/08/05 

Date: Tue, 08 Feb 2005 22:34:42 GMT

"Michael McCulloch" <michaelm@nospam.invalid.net> wrote in message
news:brci01tci8q60bt9fnil4eotrh4toqnoab@4ax.com...
> On Tue, 08 Feb 2005 11:44:14 GMT, "Roger Hamlett"
> <rogerspamignored@ttelmah.demon.co.uk> wrote:
>
>>Vixen also have their 'Sphinx' system, which is a
>>nice 'gadget', but 'good in parts'. The motion basically, is good, but
>>there is no software PEC correction.
>
> True, it would be nice to have, but is not necessarily a necessity.
> There are indications the tracking may be good enough without PEC for
> short focal lengths (<1000mm) in Build 26.
>
> Here's a single *unguided* 250 sec exposure I took this weekend:
>
> http://gamesforone.com/stars/images/b33.jpg
>
> Does the PEC really work on the lower cost Celestron and Meade mounts?
>
>>Only recently, have they got the
>>autoguiding to work (this is a charged for upgrade to the software).
>
> $20. Not a serious cost issue here.
I agree, except that when the mount was originally marketted, there was no
suggestion that it would be charged for. In fact a couple of the early
advertisements, were phrased to say that it would be free. It was a little
'naughty' by the marketting department...

>>The
>>backlighting on the display, and the polar scope, are both too bright,
>>with the latter improved a little on the latest software, but the
>>former,
>>and 'inherent' fault, in the technology chosen, and requiring the
>>addition
>>of a ND filter to dim the display to reasonable levels.
>
> Overblown. The ND filter works ok and Build 26 now has a timer feature
> whereby the display turns completely off after a user-adjustable time
> period. If you use the ASCOM driver for remote control, the backlight
> never even comes on.
I still find the display annoying. There is no illumination to the
buttons, which are too sensitive to be comfortable in the cold with gloves
on. So have ended up with a ND filter, in a custom made 'case', which has
the buttons recessed, with rings round them, so you can feel them in the
dark. Compared to the used interface quality of the SS2K, it is not even
in the same 'class', and it is wrong that the unit should need an add-on
filter to work acceptably. Turning the display off, doesn't help if you
have already destroyed your night vision...

>> It has the
>>feeling, that the basic mount was designed by astronomers, but the
>>software, was 'farmed out' to a sub-contractor, who does not really
>>understand what is needed.
>
> Nah, it is just different than the Nexstar and Autostar hand paddles.
> I am starting to really like my Sphinx now that the problems seemed to
> be corrected. With the ASCOM driver, you can control it with any
> ASCOM-compatible software program. I use SkyMap Pro. Plus the scope is
> driven by ASCOM through an Ethernet port -- a step up for those that
> use laptops for remote control.
Yes. This is one part I really 'like', except that the interface should be
going to the scope mount, and not to the hand controller. If you are using
guiding, you have the main cable, autoguider cable, and ethernet cable all
routed to the hand controller. I can understand 'why', but it does not
make it 'nice'.

> Theoretically, you should be able to autoguide over the Ethernet port
> using the PulseGuide commands available in ASCOM. I am currently
> working on getting GuideDog setup to do so.
>
> The Sphinx deserves a more serious look.
Yes, it is a good mount now, if you can live with the remaining problems,
but it should have been 'excellent' from day one. On the display for
example, the brightness is because they went for EL backlighting. This is
the commonest solution for laptop displays etc., However you can get the
same displays with LED backlighting, which gives a slightly less smooth
backlight, but can be dimmed to nothing. Also there are other display
'versions' available, including the transflective forms. These have the
advantage of being visible in daylight, without depending on the backlight
(these are suddenly taking off in the phones and similar devices). This
sort of display combination, is an 'off the shelf' answer from many
suppliers, and would have given a display that could be seen in the
daytime, when solar imaging, and be as dim as needed at night. I have been
involved with a couple of systems using this type of display, and they
would have been a far better choice.
I think I am spot on, in my assesment, that the handcontroller was 'farmed
out' to a team outside the company, who are not involved in astromony, it
explains exactly why a system that is in places truly excellent, is marred
in this area.

Best Wishes