March 31, 2019 – First attempt at autoguiding with the SkyWatcher EQ-3 Pro
đ A Dream, Interrupted
Autoguiding had become my next big step â the gateway to longer exposures, better tracking, more usable data, and less frustration with drift and alignment. I had read all about it. Planned for it. Bought the gear. And then came the night.
The one where nothing works. The one that nearly blows you away.
But letâs back up for a second.
đ§ Why Guide at All?
Autoguiding offers three key benefits:
- Improved polar alignment:
Using PHD2 and a guidescope, you can track star movement to get precise feedback on your mountâs polar alignment. PHD2 even tells you how to nudge your mount â a huge help compared to visual guesstimates. - Plate solving via the guidecam:
Plate solving uses an image to identify exactly where your scope is pointed by comparing star patterns to a database. My Olympus E-510 canât be controlled remotely, so touching the camera mid-session would destroy my focus. The guidecam solves this â it can plate solve independently, leaving the main camera untouched. - Actual guiding during imaging:
With PHD2 sending real-time corrections to the mount, I can:- Use longer exposures (beyond my 50â60 second ceiling)
- Eliminate frame drift over time
- Drastically improve my keeper rate (sometimes as low as 1 in 5 frames before guiding)
It was time. I had the gear. I had the plan. I had⊠no idea what was coming.
đŠ The Gear
Guidecam:
- ToupTek G-1200-KMB Mono Guider
- CMOS sensor (AR0130CS), 1280Ă960 px
- 8 / 12-bit data output
- No active cooling
- Price: âŹ164
Guidescope:
- Omegon Microspeed Guidescope 50mm
- 200mm focal length, f/4
- Price: âŹ129
- Weight: 610g
đ» The Night That Went Nowhere
Everything was set up: mount leveled, balanced, aligned.
Cables connected. Camera detected. PHD2 running. And thenâŠ
Nothing worked.
Two different failure scenarios played out:
Scenario 1: 8-bit mode = Sluggish
- Frame rate dropped to 1 frame every ~10 seconds
- Eventually, camera disconnected completely
- Guiding was impossible due to low FPS and constant dropouts
Scenario 2: 12/16-bit mode = Speedy but silent
- FPS jumped up to a healthy 30+ frames per second
- But no guiding commands reached the mount via ST4
- It was fast â but it was guiding into the void
My best theory?
In 8-bit mode, the camera downsamples onboard â choking the USB bandwidth and blocking ST4 communication. In 12/16-bit mode, the USB bus gets flooded with data, and the ST4 impulses just disappear. Even on my stationary PC, the result was the same: ST4 or FPS â never both.
đ Aftermath
I spent hours swapping settings, restarting drivers, reinstalling software, even trying different USB ports and cables. Eventually, I gave up and contacted the retailer. To their credit, they were responsive â and we agreed to swap the camera for a ZWO ASI120MM Mini.
Looking around online, I found out this wasnât just me. Others had experienced the same issues with this ToupTek model. Whether it’s an unlucky hardware/software mix or a deeper flaw in the cameraâs architecture⊠I still donât know.
đ§ Conclusion
The night before, I thought I had tested everything. In 16-bit mode, the FPS was fine, and Iâd even managed to get the ST4 port to respond (once, accidentally). I thought I was ready.
I wasnât.
If this happens to you â if everything breaks, if nothing works, if you feel like your scope might as well be a boat anchor â know this:
Youâre not alone.
This hobby is beautiful, but itâs also one of the most complex, multi-variable, unforgiving things Iâve ever touched.
Thousands of things can go wrong. And sometimes, they do. All at once.
But thatâs also where the growth is.
„Keep calm and try again next night.“
Because one day â maybe not the next session, but the one after that â it will all click. Youâll look at the image on your screen and smile. Youâll know: This time, it worked. And you earned every pixel.
Clear skies and strong nerves,
Chris