Reading Michael Swanson’s “The NexStar User’s Guide II” – Chapter 05 – NexStar and StarSense Hand Control Operations
Chapter 5 (of Michael Swanson’s “The NexStar User’s Guide II”) is entitled NexStar and StarSense Hand Control Operations and you would be right if you assumed this was going to more like a software manual than a telescope manual. It is a highly specific reference manual for the use of the hand controller and reading it page by page is for the hard-core geek only. But it is full of fantastic info that I didn’t know enough about, even though I’ve worked with the hand controller for years. These are the highlights for me:
Pg. 128 – Adjusting slew rates…I knew how to manually adjust the slew rate (MOTOR SPEED then press 1-9 where 9 was the fastest). I really only use 3, 6, and 9 for rates though. 9 if I’m going a great distance, 6 if I’m adjusting for centreing, and 3 if I need very fine adjustments while doing astrophotography and looking at centreing something on the screen. However, I didn’t know that if you were slewing in one direction (say left) and also held down the opposite button (i.e., right), it would temporarily speed up to rate 9. I have no idea when I would ever use that, but it’s good to have. I suppose if I knew I was going from rate 6 to something that was farther away and wanted 9 temporarily and then back to 6, I could do the temporary speed boost.
P. 130 – SAO stars…I knew the list was there, I didn’t know that you could type in a few digits and that served as a “filter” so that 0004 would give you a list of 000400, 000401, 000402, etc. with only the visible ones at that time showing up in the list. Not sure I would ever use it much though.
P.130-131 – Sky Tour…I use the sky tour regularly, and have always wondered about the methodology it uses. While there isn’t much detail on that in the manual, it does note that it is the same Sky Tour in my son’s 4SE as well as my own 8SE, with no adjustment to the software to recognize that some objects might not be suitable for that particular scope.
P.132-133 – Anti-Backlash/Backlash Compensation…The previous chapter already covered this from a physical setup perspective, this gives you the walk-through for the software side. Still need to do this.
P.135 – Slew Limits…I have had an occasional problem with my slew limits, and I didn’t really understand how they were working. The Slew Limit tells you when something is too far up or down for your scope to see, perhaps because of what you have attached to the scope (like a camera) or could be for permanent horizon. I set my scope up so that nothing CAN hit the base any more and I almost NEVER go to zenith anyway. But I occasionally get slew limits for something that is too low. What I didn’t realize is that my setup is throwing off my limits. I physically install my tube with the mount vertical and pointing up; my son does his vertically, but with the mount pointing down. We install the tube, turn on the scope, and go to horizontal. I didn’t realize that the scope THINKS you start horizontal. So, we need to make it horizontal, and then restart the system to reset the counter to horizontal. We haven’t had any problems, but there were a few objects here and there that I thought we should be able to see and the scope said “Nope”. Might be why. Need to adjust that as part of my setup technique.
The Filter Limits (P.136) is the temporary version of slew limits, in a sense, and is usually related to horizon. I wish it would allow you to just point to your horizon and say “Use this as your lower horizon limit” and to allow you to do it in multiple directions. I have zero viewing sites that have all 4 directions with the same horizon. My backyard is great to the South, maybe 15 degrees. East and West are more like 60 degrees with houses. North is perhaps 45 degrees. If I set it by the limits East and West, the highest, I’ll miss out on a ton of objects to the South and North. At the Carp site, great views to the West, but North and East has a hill and South has some trees. Not huge problem, they would work okay there. The FLO site has trees to the East and North, but better views to South and West. AstroPontiac is fantastic in almost 225 degrees, but the Gatineau Hills right behind it for the other 135 degrees is another story. And at the in-laws’ cottage, West and South are awesome, while East and North are about 85 degrees straight up for trees. I know some of the software options for tablets and planetariums will sometimes allow you greater flexibility for simulating your view, not sure it changes much for scope control though.
P.137-138 – GoTo Approach…This was covered for the physical side in Chapter 4 on alignment, and notes the default settings for back-heavy and front-heavy scopes, with the recommended settings over the defaults. I want to try this soon too.
P.140-141 – User Defined Objects…I had seen this in the menus but really had no idea what it was about, nor did I understand the sub-menus much. I loved the explanation on these two pages to know there are basically 99 memory spots to remember UDOs. If I choose my own object in the sky, and pick SAVE SKY OBJECT, the computer will add that location’s coordinates to memory, but unfortunately with no option to edit the name. SAVE DATABASE OBJECT does the same but for objects already in the main database, and so it retains the name too. Interestingly, you could program your night’s viewing ahead of time using this method as the scope doesn’t need to be aligned. You would essentially be creating your own personalized star tour. ENTER RA AND DEC would do the same, albeit without a name. When you want to use the list, pull up UDOs and choose GOTO SKY OBJECT. I’m curious to see if I can pre-program those with software, but I guess if I’m using the apps, I don’t even need to use that as they allow custom lists / catalogs anyway.
P.141 – Display settings…I need to check to see if I have LCD Contrast and Bold Font set for my hand controller, I sometimes have trouble reading it. And I can do the same for my son’s.
P.142 – Cord Wrap Prevention…It sounds strange to say, but I hate the Cord Wrap Prevention. Why would I hate it? Because while I like the general premise of stopping the scope from getting all tangled up and pulling on the power wires, my Sky Tour starts near M110 and the Andromeda Galaxy. Then, as I go along, and as I get close to due North, the scope can get a bit confused…it hits the cord wrap limit (North), and then to get to the next object (across the limit line), it goes ALL the way back around, as it’s supposed to do. I would much prefer if that limit line was close to M110 so that for a sky tour, I could do almost all of it before running into that problem. Particularly as a couple of elements shift a bit in the order, and one will be past the limit (all the way back around) and then an object or two later, will be back across the limit (so all the way back around again). If I could adjust it closer to the right (East/South) of M110, I would be able to do almost the whole tour without that problem. And since I am rarely in that section of the sky in most of my sites, it would be a good limit anyway. Except the only setting seems to be ON or OFF. Sigh. I’ll check with the author to see if there is any way to edit this.
** Update: I heard back from the author, who was very polite considering I missed something he had already explained in the book. I just mis-read it, as I was looking for something that says “here’s how to edit”, and that isn’t quite how it works. Apparently, the default setting is due north (I thought was “near North”, but no, it is actually North) and since I always leave it on, I’ve never see an option to change it. But if I turn cordwrap OFF, and then turn it back on, it will then ask me to point to the exact opposite point of where I want cordwrap to be. At present, the default of SOUTH means the mount thinks my cable starts to the south, so when it gets half-way around to NORTH, it activates the cord-wrap. So, if I want to activate cordwrap “east of M110” which has RA of 0h, I need to toggle CORDWARP and then point the scope to an RA of 12h (directly opposite M110). That initially seemed ludicrous to me, but the author further explained that it is asking you to point to the centre of the available range of motion. Ah-hah! That makes sense! Except then I found out that if I’m using Sky Portal, I can’t change the setting, it’s always due South. Sigh. Cuz I want to start using that! **
P.147 – Direction Buttons…I already mentioned this in the physical setup / alignment section as it messed me up. I had inverted controls set ON by default, and it meant that my UP and RIGHT should have been DOWN and RIGHT, so my alignment process always included altitude slippage. FOR FIVE YEARS. Arghh!
P.147/148 – Hibernate…I have wanted to try to see some planets during the day for a long time, just to see what you could see. But it’s impossible to do an alignment, right? Well, in addition to the option to do a solar system alignment (even on the moon or sun), you can also align during the night, and then put your scope in “hibernation” mode like a laptop. Then, when you want to use it during the day, you can wake it up, don’t MOVE anything, tell it the current time, and voila, you’re back in business. It already knows your location, and where it is in relation to the stars a few hours before when you did the first alignment, now it just needs to know how long it was sleeping. If you do ANYTHING else before entering the new time, the alignment is lost. I really want to try this, except for one little thing. Well, two things. First, dew would be a pain. Second, it would work best with a great alignment in the wee hours before dawn…yet I am NOT a morning astronomer. I even struggle to stay up much past 1:00 a.m. But I do want to try it sometime.
P.150 – Version…I figured SOMEWHERE in the handset there must be some indication of what version of firmware is running, so I will have to look that up, now that I know how!
As I said at the beginning, this is the hard-core manual side of the software. Most people would likely use it as a reference guide, “How do I….”, but it was fascinating to read the whole thing at once and see other settings that I might use. Great chapter.
