Is Anything Tracked When You Move Off Target?

[geministar]

I should try this, but just thought I'd ask anyway.

Celestron GoTo.

When it slews to a target, it then tracks it.

But if you then move it without GoTo to another object, what is then being tracked? The new object? Or none?

[Merlin66]

With the SW EQ mounts you can use the handcontroller buttons to move the scope to a new object and the tracking recommences when you stop the slew.

[happy-kat]

There are different tracking speeds, eg one for general stars and another for the Moon etc. So it just carries on tracking at the speed set. Rather is it not tracking the object you specifically looked at but tracking the sky's movement in general at the rate selected.

[alanjgreen]

goto scopes don't track any specifi "target" they just track to compensate for the earths rotation meaning that your eyepiece view stays the same.

if you move the scope it will still track at the same rate to compensate for the earths rotation just as before - it is not looking and tracking a target you picked in the sky

tracking is there to keep your field of view steady.

Alan

[geministar]

Thanks for the replies!

Small further issue: if it's tracking the Moon, then you move to a star (or vice-versa), will the tracking rate not be wrong?

Without identifying the new target, the system won't "know" what rate to use, will it?

[Merlin66]

No, you'd have to change over to siderial rate tracking.

[geministar]

Got it!  

Once set, tracking continues, even after you move off-target.

And if you move from a planet/Moon target to a star/DSO target (or vice-versa), you need to re-set it.

[ollypenrice]

In reality, though, the lunar rate is close enough to the sidereal for visual observing. I never bother changing the rate to observe the moon. I might if I were going to be imaging it in a large mosaic.

Olly

[geministar]

In reality, though, the lunar rate is close enough to the sidereal for visual observing. I never bother changing the rate to observe the moon. I might if I were going to be imaging it in a large mosaic.

Olly

Very good point, most informative - thanks!

[LukeSkywatcher]

Sorry Gemini. This thread answers/explains things better than i did on the other thread. You are not tracking a particular object but rather the rotation of the night sky. Yes, if you move off of your initial target the scope will still track the night sky and any object you decide on observing. 

I have tracked the Moon and moved off to another target and found no need to change the slew speed of the scope. Maybe the only time to speed up the slewing speed is while observing planets like Saturn............all depending on what magnification you use. Saturn can rave across the FOV if you use too high magnification.

Ive set my scope to track. The moon was my target. I went inside for an hour and when i came back out the Moon was still slap bang centred in my FOV.

[geministar]

Sorry Gemini. This thread answers/explains things better than i did on the other thread. You are not tracking a particular object but rather the rotation of the night sky. Yes, if you move off of your initial target the scope will still track the night sky and any object you decide on observing. 

I have tracked the Moon and moved off to another target and found no need to change the slew speed of the scope. Maybe the only time to speed up the slewing speed is while observing planets like Saturn............all depending on what magnification you use. Saturn can rave across the FOV if you use too high magnification.

Ive set my scope to track. The moon was my target. I went inside for an hour and when i came back out the Moon was still slap bang centred in my FOV.

Thanks, Paul.  Reckon I've got the idea now.  Pity the manuals don't spell it all out clearly!  It was your comment about setting up just for tracking (i.e. not for trying to accurately use GoTo) that was also a moment of enlightenment!  Thanks again.  

(My straight thro' finder has arrived.  Can't wait to see what it reveals!)

Doug.

[impactcrater]

you set up goto to (usually) two stars...you goto to an object and of course it tracks it ...you decide to slew manually to something nearby...it tracks it...you then decide to goto another object...it just does what it is asked...the initial settings determine its goto properties. it wouldn't work well otherwise...

[LukeSkywatcher]

Thanks, Paul.  Reckon I've got the idea now.  Pity the manuals don't spell it all out clearly!  It was your comment about setting up just for tracking (i.e. not for trying to accurately use GoTo) that was also a moment of enlightenment!  Thanks again.  

(My straight thro' finder has arrived.  Can't wait to see what it reveals!)

Doug.

Thats just the way i do things because when i bought the scope i wasnt really looking for a Go-To scope (per say). I just wanted large aperture/minimum weight/maximum portability. I'm used to manual scopes and searching things out myself rather then letting the scope take me n a guided tour of the night sky. For this reason, i do a basic 1 star align or a solar system object align so the scope will track in RA.....while i use the up/down/left/right keys on the control to slew to where i want to go. To get the most out of your scope its always best to do a full 3 star align so the scope knows exactly where it is and will track 100% flawlessly. Its a good habit to get in to from the get go. I just have no need to do it as i use the scope basically in an Alt-Az kind of way.

[geministar]

Thats just the way i do things because when i bought the scope i wasnt really looking for a Go-To scope (per say). I just wanted large aperture/minimum weight/maximum portability. I'm used to manual scopes and searching things out myself rather then letting the scope take me n a guided tour of the night sky. For this reason, i do a basic 1 star align or a solar system object align so the scope will track in RA.....while i use the up/down/left/right keys on the control to slew to where i want to go. To get the most out of your scope its always best to do a full 3 star align so the scope knows exactly where it is and will track 100% flawlessly. Its a good habit to get in to from the get go. I just have no need to do it as i use the scope basically in an Alt-Az kind of way.

Thanks again.

Re the highlighted bit above - I would have expected tracking to be in alt and az (rather than RA) with an alt-az mount.  Is that what you meant, or have I just learned something new? 

Incidentally, the straight-through finder went straight back.  I can contort myself quite a bit, but it's having everything doubly inverted that I didn't like.

[LukeSkywatcher]

Thanks again.

Re the highlighted bit above - I would have expected tracking to be in alt and az (rather than RA) with an alt-az mount.  Is that what you meant, or have I just learned something new? 

Incidentally, the straight-through finder went straight back.  I can contort myself quite a bit, but it's having everything doubly inverted that I didn't like.

You are right. A go-to scope on an Alt-AZ mount tracks in both alt and az (i call it RA for some reason)...........must be something to do with my days using an EQ mount. Tracking in Alt-Az (if you can imagine it), looks more like a flight of stairs (up and right,up and right etc)......whereas an EQ mount tracks in one fluid motion (a curve), which mimics the earth's rotation more so then Alt-Az. For this reason............an EQ mount is the best choice for imaging.

Hope i have this right and it makes sense. Honestly im not very technically minded when it comes to the mechanics of scopes. I just enjoy the views.

[geministar]

Thanks, Paul. That makes sense. Tracking in alt-az is equivalent to doing it in RA, but not quite as smooth. I hope.........

[LukeSkywatcher]

Thanks, Paul. That makes sense. Tracking in alt-az is equivalent to doing it in RA, but not quite as smooth. I hope.........

Same thing essentially. Alt-Az is fine for observing ( looks fluid and smooth to the human eye) , but doesnt cut the mustard when imaging compared to RA on an EQ mount.