Alignment ...and not polar!

[69boss302]

Thanks to all of you, Ive had a lot of success in getting the hang of this lately! Tonight, for the first time ever I was able to actually guide using a guide scope and phd!  Im missing two pieces of the puzzle in my head though. Heres my setup:

-Zenithstar 73 with field flattener.

-EQ6-R Pro mount

-ZWO ASI290 Mini Mono Guide camera

-Orion 60mm Guide scope

-Camera is currently Canon EOS 1DX Mark III, I didnt hook up the ASI 2600MC Pro OSC yet.

I have a laptop using ASCOM, PHD2, Stellarium and APT.

I actually have it all working well and talking to each other! I do a rough polar alignment of the EQ6, then connect all my gear to the laptop. In Stellarium I can select an item and go to it, and that still makes me smile, its just so cool.

But heres what Im mentally missing.  How do I align my Zenithstar and camera and guide scope all together? What I mean by that is I can have PHD2 pick a star and start guiding.....but dont know what star it is. And even if I did, how  do I now align that to my main scope so they are all pointing at the same thing in the center of the field of view?

Right now, I can point to a star, and it goes to it.. but it does not mean that what I pointed to in stellarium is in the center of my view of my camera.  I know the guide scope doesnt really care within reason what its pointing to, its just a point of reference. But it seems to me Id like to have them all pointing at exactly the same thing.

I found this out tonight because when I pointed to something big and bright (andromeda) and took a long exposure, it was nowhere to be seen in my photo (but the picture came out GREAT!) 

Thank you for any tips on this!

bob

[fwm891]

@69boss302 Rather than trying to do everything in the dark try pointing your scope with camera at a distant object (building, church tower,power lint etc) during the day. Lock off the mount when you have your subject centred. Then adjust the alignment screws around the guide scope to centre the same subject in the guider. Tighten the guide scope. Check both are pointed at the same subject. Realign if necessary.

When you then go out at night both the optics will be looking at the same patch of sky. After you have polar aligned use your handset to do a star alignment using 1, 2 or 3 stars. Then you should be able to find anything above your horizon.

Later when you’ve got more confidence with things you can use plate solving to sync the mount to the sky.

[StevieDvd]

OK your problem is possibly a polar alignment, bad home position or a date/location setting.

You do not need to have your guide scope and main scope/camera pointing at the same object.  The guide scope can have an offset from the scope, sometimes this is preferable. It's more important that the offset stays the same when aligning/using the setup.

Your guide scope allows you to choose a star near to your target and if you have correct PA and date/location the movements around the mount axis it makes are the same as the target.

If you have a good PA, which your long exposure and GREAT image then it' s either your location/date is wrong or your software and the actual mount position dis-agreed.  Let's say for example you were perfectly polar aligned (and dates set correct), you centred on a target and started guiding you would get a good image as the mount moves correctly. Then you do a goto the target would be off screen but still moving at the correct rate.

Stellarmate has the tools to help you get this sorted, there is a good PA routine, then a goto with platesolving activated will synch you mount and the software. And it seems you've got the guiding worked out so well done.

One thing to try is to repeat what you do at present, when you tell Stellarmate to goto a target and it' s not in the view, undo the clutched a little and centre the target and re-tighten them. Then do another goto and see if that is now correctly centred. Platesolving does the opposite it checks what you are looking at and adjusts the software to match.

HTH & welcome to SGL

Steve

 

[69boss302]

4 hours ago, fwm891 said:

@69boss302 Rather than trying to do everything in the dark try pointing your scope with camera at a distant object (building, church tower,power lint etc) during the day. Lock off the mount when you have your subject centred. Then adjust the alignment screws around the guide scope to centre the same subject in the guider. Tighten the guide scope. Check both are pointed at the same subject. Realign if necessary.

When you then go out at night both the optics will be looking at the same patch of sky. After you have polar aligned use your handset to do a star alignment using 1, 2 or 3 stars. Then you should be able to find anything above your horizon.

Later when you’ve got more confidence with things you can use plate solving to sync the mount to the sky.

Francis, I actually thought of doing that during the day but I figured the convergence would be way off. Aligning my scope to the OTA at something a mile or 5 away would be dramatically different than something hundreds of light years away, but I could be wrong, or it may not matter that much. Either way, I think you are correct, it will sure get me closer than I am currently.  As for the handset I havent used it yet but that is also a good idea. Thank you for your input.

[fwm891]

@69boss302 If you can see a target at 1 mile the practical difference in positions against the sky will not be worth worrying about.

[KP82]

For imaging as long as the guide setup is pointing roughly at the same vicinity as the main scope that will be enough. Unlike for visual there is no need for precise alignment between the main scope and guide scope.

[newbie alert]

As above, no need for the guide scope to be pointing at the same target as the imaging camera, as long as it's pointing in the same direction..

If your image came out well with nice stars etc then your polar alignment is good.. just your pointing( gotos) so you either need to refine your star alignment or the date/ time location is wrong or look at using a plate solving software such as APT and NINA,  SGP  or even sharpcap