5 replies to this topic

[Terry LS]

Ok folks/mates, I recently got my Celestron GPS 8" connected to stellarium using the right serial cable.  That problem is now solved, thanks to Mike and the other knowledgeable fellows!  Now for my next question:

After I align with two stars...I slew around looking at things (which is great) for awhile and notice some objects are not centered in EP as well as earlier.  Now that may mean a few things.  But can I REalign the object in the center of the EP and tell either the mount or Stellarium that it is now a REalignment and continue on???  If so, after recentering in the EP, which button/keys do I let the mount/Stellarium know that I REaligned that object in the EP?

Thanks folks

[56S]

I use the mobile version and have a sync feature that I touch after centering the object. My SkyWatcher will work with Stellarium but still needs Synscan to act as a go between.

Centering the object in the eyepiece when doing an alignment turns out to be more important than I originally thought. A double x hair illuminated eyepiece made a world of difference in my goto accuracy.

Stellarium has been excellent in replying to my questions via email.

[12BH7]

If you slew the scope around enough the calculation errors will start to become additive.  Errors arise from not having alignment stars dead center (most common), slewing to vastly different parts of the shy, perfect orthogonal relationship in the mounts axis, slippage of encoders due to you pushing in EP's and accessories, etc....

 

I usually realign if I start to notice a real problem after 20 or so objects. Otherwise I just accept the error and go on with my night.

[Terry LS]

If you slew the scope around enough the calculation errors will start to become additive.  Errors arise from not having alignment stars dead center (most common), slewing to vastly different parts of the shy, perfect orthogonal relationship in the mounts axis, slippage of encoders due to you pushing in EP's and accessories, etc....

 

I usually realign if I start to notice a real problem after 20 or so objects. Otherwise I just accept the error and go on with my night.

True, I did slew alot!  Also only did a "two star" alignment.  Maybe I'll do a three star next time.  Also have a few hours do a New Alignment over!  All is good.  Just though maybe a "shortcut" was available.  Thanks

[12BH7]

I haven't found a significant differences using a two star vs three star alignment. That may be important for AP (??), but visual, stick with the two star. 

[12BH7]

Also, if you plan on observing in a section of the sky, try to pick your alignment stars in that section. That will improve accuracy. Swinging from one end of the sky to the other just adds up the errors in the DSC calculations.