Newly arrived to my blog? Want to know more about me before you dive into my posts? Why not visit the home page first and start your exploration from there:
https://undersouthwestskies.blogspot.com/2025/01/welcome-to-my-new-astronomyastrophotogr.html
And welcome. Welcome to 'UnderSouthWest Skies'. Thanks for stopping by. I hope you find the experience worthwhile. This blog post has been written from my own 'beginner perspective' after doing lots of reading on the topic below. In getting my head around it all, I may have got odd bits slightly wrong; but, like you, I am on a leaning journey, so please forgive any unintentional errors. Meanwhile, clear skies to you. Take care and thanks for visiting Steve aka PlymouthAstroBoy
Date: 31st January 2025
Location: Wembury Beach car park
Time: Arrived around 1815 - set up by 1900. Polar alignment completed by 1915
Conditions: perfect - cloudless skies until 0100; no wind; temperature 3C falling to 1C by 0000.
Target: NGC1499 The California Nebula
Equipment used: SWSA2i, Canon 800D unmodded, Zenithstar 61ii, various power banks etc;
Shooting plan intentions: 40 x 300" lights and then 15 of each calibration frame
I love having a plan for a shooting night. I hate it when the plan goes out of the window almost immediately!
Initial balancing of the tracker went fine in both RA and DEC. Polar alignment was spot on.
Would it track?
No! All over the place - at one time the tracking went 'West 50 steps' and still hadn't timed out. Without guiding - there was star trailing after 5".
Four times I broke the rig down and reassembled it. Four separate polar alignments, all accurate. Four balancing the tracker - all done.
Still the same result. I lost two hours of shooting time.
I changed the tracker batteries as well by the way. I tried everything - altering calibration settings in my ASIair mini - the lot! Nothing. Nada! 😱
Eventually, I managed to get the whole thing to guide accurately and also shoot 120" exposures on the Owl Cluster. It was just to the North West of Polaris and so my small refractor scope with its camera were facing to the north west. It seemed to cope with this position as the counterweights were just off the vertical downward position and the camera/refractor rig almost over the top of the tracker.
At 0400 this morning and sat bolt up right. Wait for it! Its a classic! Don't judge me! You will want to but resist the temptation! 😳
The sudden realisation - I had used the wrong counterweight bar on the tracker.
Let me explain. I have two counterweight bars.
One has an extra 6 oz lead screwed into the base and uses just one normal counterweight - I use this for my samyang 135mm and canon rig. Balances and tracks perfectly.
The second counterweight bar - uses just two normal counterweights and I use that on the zenithstar. Balances it perfectly and the tracker seems to do its thing with no problem at all.
Yep, you are one step ahead here - I used the two counterweights AND the extra 6oz or so counterweight bar.
So, my thinking. I think the tracker couldn't cope with the extra weight and so wouldn't lift properly. The position to shoot the nebula was with the camera and refractor rig to the east and the counterweights to the west and the whole assembly was practically horizontal to the ground.
So I am left wondering whether the tracker just couldn't cope with the weight and so the guiding wouldn't function either?
Paranoid that I have stripped the gears in my tracker, I now have the rig fully assembled in the front room and I am testing that the tracker is working as it should. I will let you know the outcome in a few hours! 😬
PS: at least I got to see the parade of planets across the night - starting in the east with Mars just by Castor and Pollux, across to Jupiter and then the other planets as mentioned above.
Meanwhile - I am feeling sooooo stupid! 😕
No comments:
Post a Comment