The display will show the current time zone setting as some number of hours ahead of or 

behind the time in Greenwich England.  For example, the United States west coast is 

UTC 8 hours or 8 hours behind Greenwich when daylight savings time is not in effect.  

Press the DEC+ or DEC  buttons to scroll through the time zones.  When your time zone 

is displayed, press the RA+ button to select it. 

2.4.2.3  Preferences 

Finally, there are some preferences that you can set to tailor Gemini to your liking and to 

your particular mount.   Most of these are optional and can be changed any time.  Such 

items include: 

Hand Controller Mode (Visual, Photo, All Speeds) 

Moving Speeds (Slew, GoTo, Center, Guide).  Changing the Slew and GoTo 

speeds may be needed if a motor keeps stalling during a slew.  Often slowing 

these speeds down helps. 

 Brightness of the HC display 

Refer to chapter 5 for details about setting these and other options. 

Important:

  Changing your geographic location between northern and southern 

hemispheres will reverse the tracking direction (and because of this, also the Safety 

Limits).  Gemini makes even more internal adjustments when you change the Mount 

Type. If you alter either the Mount Type or hemisphere, restart the Gemini after 

completing the Setup operation.  Simply turn Gemini off and then on again to do this.  

Also, if you are using a mount other than a G 11 (the default for the Safety Limits 

assumes you are using a G 11), you must manually set the RA Safety Limits.  Please 

refer to section 3.3.3 for instructions on how to do this. 

2.4.3   Refining the Mount's Alignment Model 

Let' s review where you are at this point:  You have assembled the mount and telescope, 

and have carefully balanced them in both RA and Dec.  You have leveled and roughly 

polar aligned the mount by pointing the mount' s polar axis at the celestial pole.  You 

have positioned the mount in the Startup Position with the counterweight down and the 

telescope pointing north (or south if in the southern hemisphere), and powered Gemini 

on.  Finally, you used Gemini' s menus to set the various parameters to make it work.  

You are now ready to align Gemini' s internal modeling parameters. 

In order to accurately point to objects in the sky, the Gemini software needs to know how 

the mount is oriented with respect to the celestial pole, what angle the telescope is 

pointing to in both RA and Dec., the degree of non orthogonality between the telescope 

and the mount, etc.  All of these parameters form Gemini' s   model   of the mount and 

telescope.   These parameters as well as others are built up automatically through a series 

of alignment operations.  Each alignment consists of pointing to a star and telling Gemini 

when that star is centered.    Accurate modeling allows accurate GoTo operations, and the 

more alignments you perform (up to a point), the better the modeling parameters can be 

Gemini Users Manual 

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