Guiding issue

[Vali x]

hey guys. since i started to use my SCB2k i noticed my scope doesnt do a proper guiding! weird! i take all the steps to ensure a proper alignment, but on my laptop i can notice that the DSO is moving out. i dont have yet the budget for a guiding scope, but i assume i am doing something wrong! any ideas?

[Joel_L]

I am not familiar with your scope but a thought that comes to mind, are you setting or is the mount automatically setting the tracking speed correctly? The speeds are different for various objects.

Joel

[Vali x]

not a clue what you refer to....i dont have an option to setup any speed, as per my knowledge

[jenniferchristine]

There are only two speeds, solar system and DSO - so it won't be that.
However the motors may be untrained and you need to do that to ensure that they are giving the right number of steps per degree.
See your manual - training drives.
The other reason could be a slippy clutch, but that usually results in jumping and jerking rather than slipping gently off into oblivion.
The last one is balance, make sure your rig is balanced so it doesn't put undue strain on the motors.
Then, so long as you ARE polar aligned, you should be spot on

[satcomsta]

There are only two speeds, solar system and DSO - so it won't be that.
However the motors may be untrained and you need to do that to ensure that they are giving the right number of steps per degree.
See your manual - training drives.
The other reason could be a slippy clutch, but that usually results in jumping and jerking rather than slipping gently off into oblivion.
The last one is balance, make sure your rig is balanced so it doesn't put undue strain on the motors.
Then, so long as you ARE polar aligned, you should be spot on

Ok, so the counter weights issue is very important(not that the other's aren't), as it also happens to me on my CG5 ASGT. Sometimes it works wonderful, but if I touch that scope, guiding goes to heck! So I'm down grading to a lighter guiding scope starting tomorrow with an Orion ST80 to replace my Orion 120ST. I figured out that is better than to add to much counter weights to the mount, maybe overloading the motors. And like jenniferchristine said, make sure the polar alignment is spot on. That will get you drifting real quick.

[Joel_L]

Add lunar. I see that it also has Nexstar, so should set the rate according to the object selected.

[Vali x]

well, i am using the polar "hole" to make sure my mount is properly placed; there are 2 things that i didnt figure out yet:1- not a clue what that RA hour ring and knurled nut needs to be setup; 2:i do 2 star alignament+2-3 calibrations stars..but i read that the hand controlller gives you the option to do also a polar alignament...not a clue! i thought the mount alignament suffice!!! these 2 issues could show me the good path, exempt no1 explained to me...
@jen&sat:i marked with white paint where i need to place my OTA to be balanced. i assume i need to re-paint the places, b/c i dont remember if the balance included the SCB2k at the time when was done! hmm!
@joe: i have my rate at sideral...that was advised by several ppl on different forums!

[Joel_L]

When you select polar alignment, it helps you refine the initial "physical" alignment you did. The key with the controls polar alignment is that you are moving the mount to align on the start the control pointed to and not slewing the telescope. If you are trying to take images, you want to do this step. The 1 start, 2 start... alignments are good to help the go to function land on your target, but will not be tracking good enough to do any long exposures. When you are looking through the alignment hole, do you also have the alignment scope? in any case this gets you close for the initial setup. After you do that, do a 1 or two star alignment so that the go to will land reasonably well on a target, then do the polar align. Follow the prompts, there will be a step where it tells you not to use the slew controls but to physically move the mount to center the object. I have a CGEM that has a latitude knob and a pair of knobs to rototate the mount, yours may be similar. You use those to physically center the object. Even here, you will want an eye piece with a grid or cross hairs to make sure you are really centered.

Sideral is the correct rate for DSOs and the controller generally picks the right speed for you based on what you asked it to find

Remember that when it comes to alignment, the one start, two start... are generally good enough if you just want to be able to have something show up in the eye piece when you go to it. For andy kind of long exposure imaging you will need to do a careful polar alignment. Does you set up have auto guiding?

Joel

[Vali x]

Joe, i dont do AP, just normal video with my SCB2k connected to my laptop. my mount is a GOTO, i try to make a good alignment using the camera, Sharpcap with the crosshairs...but where do i need to check for autoguiding? is an option in the handcontroller? or is a guidescope controlled with PhD? it crossed my mind for such thing, a 2-300 $ purchase, but i was thinking if will help. normally, my mount should do a proper guiding, but apparently i was wrong

[KeithBC]

It sounds like you may be confusing tracking with guiding. Tracking is the simple motion of the mount to follow the night sky. If your mount is polar aligned (and it sounds like that is your main issue), it will track. Guiding is a more complex automatic adjustment using a dedicated camera to provide feedback to the mount and make tiny adjustments in its movements based on what it sees. Your mount may be capable of accepting guifing inputs, but it is not an option that you can select on the hand controller. You would need to buy guide scope and camera. Guiding is necessary for long exposure photography. It is unnecessary for video.

Before you can even think about guiding, you need to endure that your tracking is good. That starts with an accurate polar alignment. If you are using a "hole" for polar alignment, that means that you do not have a polar scope. You really need one if you want to get an accurate alignment. Before you think about getting a guiding system, you should get a polar scope for your mount. Without one, you will need to do a drift alignment.

With an accurate polar alignment, yout target should stay in the field of view for hours. It should stay in the centre long enough to get a crisp 60-second exposure. Until you can get a polar alignment of that accuracy, it is premature to think about guiding.