astrophotrography by Don

What I have settled in for setup and alignment procedures

This is a work in progress.

This describes my latest set of procedures that get me to the point of starting to take the stacked pictures of whatever target I am trying for.

First, my setup is a Sky-Watcher Star Adventurer 2i, with a Canon 90D, and a Redcat51 250 mm lens, and an extra counterweight over what comes with the Star Adventurer kit. I also have a Celestron mobile phone holder that I mount on the telescope.

The Star Adventurer is an equatorial mount system, but it is not a go to mount. You have to do the alignment to true north, and use some method (for example what I outline below) to align to your target. I am not very good at this, but I am good enough to have no star trails with a 2 minute exposure.

I do have one issue that I have had to work around on this mount, in that the reticle alignment I have to set up each time I use this, as it drifts, and it is not supposed to. Customer support is sadly lacking on this. However, this is an extremely cost effective mount that is cost effective at $400 (as of June 2024) and can be considered a good entry point. It is my only gear, as I am trying to avoid Gear Acquisition Syndrome.

My alignment also uses a very excellent app called Polar Scope Align Pro. This app only exists on IOS, so Android users will have to look for something different.

At sunset: Put tripod out, without the mount put in the holder, use polar scope align for a very rough alignment to Polaris. If I have not moved latitude, then that portion is not touched.
Take the mount, put on the counter, and view towards window framing, if not vertical, loosen clutch; align to vertical, tighten clutch and recheck. When satisfied, dial to October 31. Mount onto the tripod. Put on the red light insert
At twilight, go out and get a rough alignment on Polaris. It still should be somewhat light out so that Polaris is the only star in the scope. Remove red light insert
Finish mounting the counterweight. You will need to loosen the clutch. Mount the camera and verify that everything is in balance. Reset RA to October 31 and reverify vertical.
Mount the phone onto the lens and bring up polar scope align and push to your tracking star.
At this point use a red light flashlight and polar scope align on the ipad, and tune in the alignment as best you can. Take eye glasses off for this.
When satisfied on alignment, turn on the mount to start the counter rotation. This is the "star" icon on the dial.
Using polar scope align on the phone, start the push to the star you have chosen
Take the lens cover off the red cat 51
Connect IPAD to the Canon
Set up for manual exposure 30 seconds and asa of 1600 or 3200
Press "live" on the Canon to have what the camera sees show on the built in, this will also show with time lag on the IPAD
Take first picture and use it to check focus via the Bahtinov Mask which is still on the lens. Adjust focus and retake and recheck. You should not have to download the picture but can.
Remove Bahtinov Mask and take first alignment picture.
Download to IPAD, then go inside, switch to home network on IPAD and upload to account on https://nova.astrometry.net
When solved, use stellarium to see what astrometry identified relative to your target. Adjust and repeat. I find that when the target appears in the frame, then it is a matter of adjusting to center. Astrometry will not be needed
At this point try for a test exposure. If you are going for more than 30 sec, switch the camera to Bulb, set up the intervalometer to one exposure of the time you want.
I always set for a 10 sec to start exposure and 5 sec in between exposures.
After checking that there are no star trails, set the number of exposures to what you want

If there are star trails, you have two options

Go to shorter times and more pictures
Use the rotated reticle viewer on the polar scope align pro, look at the date dial on the star adventurer and note that date and enter on the polar scope app (ipad) and then use the red flash light to adjust Polaris postion.