Sphinx SXW questions

[Fox]

Dear Southern Sphinx owners and experts

I have some questions about the Sphinx SXW (currently have an LXD75) that I would appreciate your comments and input on. I have gleaned quite bit from websites, but much of it is dated in light of software builds. User reports range for glowing to scathing, and besides, I also want Southern user comments.

Objects in Starbook. I am confused about the objects that are graphically displayed in StarBook. I understand that the Messier objects are shown, but what about Caldwell and NGC objects? (Indeed, is Caldwell in the latest build?) Can all database objects be shown as graphic objects in the display that can be slewed to? If they are not, or largely not, what’s the point of StarBook at all, you might as well just use a database handset like AutoStar.

Polar scope. How does the Vixen SXW polar scope compare to the Meade LXD75 polar scope – the latter I find to be excellent. I use the LXD75 polar scope all the time for the Southern hemisphere, and I think its illumination and ease of use is very user-friendly.

I have read that the SXW polar scope illumination is too bright red/washed out. It is this true ? Is it useful for us S.hemisphere users?

I have also read that there might be 3 ‘vanes’ that block the light path of the polar scope in the SXW – is this also true (?), does it render the polar scope useless?

Finally, is the pattern in the SXW polar scope an illuminated printed or etched reticle?

Noise: How does the slewing noise compare to the LXD75 (which I find too noisy and offensive). I believe even with max slewing, the SXW is very quiet?

Worm gear backlash and slack. OK, in the LXD75 the whole set up is crude but very user-accessible and adjustable. In the SXW its all one-piece, sealed, and (largely) not user-accessible. What’s the likelihood that the SXW will have noticeable gear backlash/slack when brand new, out of the box?

You can’t slew to a specific set of co-ordinates in StarBook – is this true ? (because there is no keyboard?) Having said that, is this of any real consequence given I would only be slewing to database objects anyway.

[JohnH]

Originally Posted by Fox

Dear Southern Sphinx owners and experts

I have some questions about the Sphinx SXW (currently have an LXD75) that I would appreciate your comments and input on. I have gleaned quite bit from websites, but much of it is dated in light of software builds. User reports range for glowing to scathing, and besides, I also want Southern user comments.

Ok that's me then...

Originally Posted by Fox

Objects in Starbook. I am confused about the objects that are graphically displayed in StarBook. I understand that the Messier objects are shown, but what about Caldwell and NGC objects? (Indeed, is Caldwell in the latest build?) Can all database objects be shown as graphic objects in the display that can be slewed to? If they are not, or largely not, what’s the point of StarBook at all, you might as well just use a database handset like AutoStar.

Messier objects are shown, NGC/IC as well, Caldwell not. Yes you can slew to any bject that is on the display star or otherwise by putting the crosshair on it in chart mode and selecting GOTO...it is WAY easier than the Autostar to use. Most iritating think about the starbook is the display is upside down for S.Hemisphere users and the only constellation it draws in CRUX.

Originally Posted by Fox

Polar scope. How does the Vixen SXW polar scope compare to the Meade LXD75 polar scope – the latter I find to be excellent. I use the LXD75 polar scope all the time for the Southern hemisphere, and I think its illumination and ease of use is very user-friendly.

I do not has the PAS however the Vixen unit is reckoned to be good by those who have used one, it is the same as for the GP and GPD I believe. The Sphinx has a metal grid over the PAS channel (to keep out umwary fingers) that may need to be removed (hacksaw job) for use with our dim old sigma Octans...

Originally Posted by Fox

I have read that the SXW polar scope illumination is too bright red/washed out. It is this true ? Is it useful for us S.hemisphere users?

Cannot really comment on this, it is adjustable.

Originally Posted by Fox

I have also read that there might be 3 ‘vanes’ that block the light path of the polar scope in the SXW – is this also true (?), does it render the polar scope useless?

See previous comment - drift alignment will get you a better result, if you want fast I recommned the iterative goto - quick and accurate.

Originally Posted by Fox

Finally, is the pattern in the SXW polar scope an illuminated printed or etched reticle?

Believe it is etched - man you love your PAS don't you...

Originally Posted by Fox

Noise: How does the slewing noise compare to the LXD75 (which I find too noisy and offensive). I believe even with max slewing, the SXW is very quiet?

Very smooth and quiet compared to what you are using - but not a silent as some.

Originally Posted by Fox

Worm gear backlash and slack. OK, in the LXD75 the whole set up is crude but very user-accessible and adjustable. In the SXW its all one-piece, sealed, and (largely) not user-accessible. What’s the likelihood that the SXW will have noticeable gear backlash/slack when brand new, out of the box?

When new the mounts tend to be overtight in RA and can have large DEC backlash, both are adjustable and should be corrected by your dealer prior to delivery.

Originally Posted by Fox

You can’t slew to a specific set of co-ordinates in StarBook – is this true ? (because there is no keyboard?) Having said that, is this of any real consequence given I would only be slewing to database objects anyway.

Has never bothered me - you can drive it from ASCOM if you wish to do this...

You have asked some odd questions, surely you would not choose a mount on the merits of its PAS? There is also the SXD to consider now with uprated carrying capacity and a new starbook it is (on paper) a better mount.

The Sphinx's main virtues are - great mechanicals for the money, portability and an elegant design, the starbook is almost, but not quite, brilliant.

Happy to say I like this mount - I had issue with it initially but they are resolved and it now does what I want it to, when compared with the EQ6/HEQ5 alterntives I think you will find the irritations suffered by Sphinx users to be minor (you do not need to strip it and degrease before use for example!).

[Fox]

G'day JohnH, many thanks for your input, I very much appreciate it! Yeah, I guess my questions are 'oddball', come to think of it. I don't drift align because I don't know how(!), haven't been shown to, and I admit I am monkey see/monkey do in this regard.

What??!! I am most surprised that Crux is (still!) the only stick figure drawn - all the websites (seem to) show stick figures otherwise - is this because of a N vs S hemisphere difference (ie. no stick figures when a S latitude is inputed?), or are the websites (and Vixen SXW manual for that matter) 'doctored' with stick figures drawn in by hand?

For better or worse, I do 'love' the LXD75 PAS, I enjoy the way I can get quite close P alignment within 2 mins of setting up the tripod, so I guess I place a lot of value on this issue.

I went to my local Vixen dealer (Astro-Optical) on the weekend, but they did not have a Sphinx on display - there was one in the box but they were not willing to unpack it for a 1st hand look. I was, however, VERY surprised that the dealer was not that knowledgable on in depth info about the SXW. Indeed, when I asked the questions above, they mostly could not supply definitive answers, despite having sold the mount for years now (!) (they were not even aware of the SXD!).

I take note that you think StarBook is easier to input than AutoStar, yes, I also think the 'text/line' driven input in AutoStar can be very tiresome.

OK, here's a final 'wishlist question'. Do you think Vixen might one dayissue a build with full constellation stick figures, and corrected up/down orientation for S hemisphere users?

Many thanks, Fox.

[JohnH]

Fox,

You will need to learn drift alignment if your desires stretch to long exposure astrophotography at reasonable focal lengths. I am self taught have you tried out the simulator here:

http://www.petesastrophotography.com...uidingsim.html

It is not as bad as it seems at first. I get initial alignment by marking the tripod leg positions where I set up - the "carry and plonk method" it gets me close enough for short exposures...

When I said CRUX is the only constellation drawn I meant the only S.Hemisphere only constellation, those visible in the N as well as the S are shown also even with a location in the S.

And yes Vixen do update the Starbook code from time to time however it is fair to say they are not very responsive to S hemisphere needs and updates are infrequest (eg PEC has only just been added) so I would not count on the updates you mention occuring soon. That said all the Vixen mounts now have some form of Starbook - perhaps this means their support staff are now free to enhance the code rather than work on new releases...

[Fox]

John H, thanks for that link!

Yeah, I am just being scardy-cat and lazy about learning it I guess. When I really think of it, given that I always level the mount reasonably OK, and its already very close to correct latitude, the main adjustment should be (and mostly ever is) azimuth, which I am sure simplifies the whole process. I know I'd have to get an illuminated recticle if I am after very precise alignment, but my 2 min quickie at the polar scope does me fine for visual use.

PS: thanks John, that's an excellent website, Fox!