29 replies to this topic

[TheNewGP]

iOptron support told me, when I last emailed them, that additional syncs do not improve the sky/go-to model. That may change in the future, not sure.

[Michael Covington]

Right, with this mount, unlike a Losmandy, doing more than one sync does not add to the model, but rather replaces the result of the previous sync.

It looks like iOptron no longer supports any modeling.  Their two- and three-star alignment were for the purpose of modeling the mount's errors, and my impression was that they were buggy (in addition to the bug in one-star alignment that displayed the wrong RA and dec).  It sounds like iOptron fixed the bugs by just taking out the code.

Again, this only affects go-to, not tracking, because once an object has been found, all the mount has to do is rotate around the correct polar axis at the correct speed; errors such as non-perpendicularity of axes do not have any effect on tracking.

[rgsalinger]

Actually, the way that iOptron mounts have worked for the past 5 years is that you could add star after star but no model was built at all either in the HC or the firmware. Each star was simply another one star alignment. This seems to have confused a lot of people. It was useful in that once you had the first star centered properly then subsequent slews worked well enough to get the next target in the FOV or on the chip. As long as the star you chose was near enough to your initial target, the mount would just keep working quite well. (I own to iOptron mounts and that's how thet work.)

 

Rgds-Ross

[Cliff Halliwell]

Right, with this mount, unlike a Losmandy, doing more than one sync does not add to the model, but rather replaces the result of the previous sync.

It looks like iOptron no longer supports any modeling.  Their two- and three-star alignment were for the purpose of modeling the mount's errors, and my impression was that they were buggy (in addition to the bug in one-star alignment that displayed the wrong RA and dec).  It sounds like iOptron fixed the bugs by just taking out the code.

Again, this only affects go-to, not tracking, because once an object has been found, all the mount has to do is rotate around the correct polar axis at the correct speed; errors such as non-perpendicularity of axes do not have any effect on tracking.

The one regret I have is selling my Evolution 8 with StarSense, used for visual observing.  It certainly seemed to me that the StarSense built an accurate sky model in under 5 minutes and then gave excellent go-to performance, possibly with more syncs being used to refine the model.  No frequent recourse to the Telrad and finder scope.

 

Its replacement was a CEM40 and I could never get it to do a good job of go-to.  Michael has now explained that that may not be on me.  Now that I am adding an ASIAir to it that will not matter.  
 

I also wonder whether a decision to drop sky modelling or not add good sky modelling to a handset might be a business decision related to handset computational hardware requirements, like memory and processor and ROM.  (Remember, the Celestron SkySense had its own, likely more expensive, handset.). Maybe it was dropped because fewer users are using it (hello plate solving) and to make ‘room’ for other software routines like the polar alignment routine (which may even make it unnecessary to use the iPolar?) in the new handsets, not to mention the hardware of wi-fi and USB. If asked to choose, the new features might be what I would choose over my original CEM40 handset.  

[rgsalinger]

The Celestron stuff is excellent for visual use. If you wanted an iOptron mount for visual I would recommend getting one of their alt/az mounts. I have one and it's excellent but I don't put long focal length scopes on it. It works very well with my 750mm refractor. I take pains to get that first star centered very precisely. 

Rgrds-Ross