SALTWATER WITCH ASTRONOMY

Power & Control for the ZWO AM5

I am using a fanless Windows 10 machine and a Pegasus Astro Pocket Powerbox to run my ZWO AM5 mount. Both of these are mounted to a SmallRig cheese plate with 3M Command Strips (I like these better than Velcro).

MeLE Quieter2Q Fanless Windows 10 PC with J4125 CPU, 8GB RSM 128GB Storage
https://amzn.com/dp/B08ZXXJL6N

Pegasus Pocket Powerbox
https://pegasusastro.com/products/pocket-powerbox

SmallRig Multi-Functional Cheese Plate
https://amzn.com/dp/B019C2ZM8Q

Sprig Cable Management Device
https://www.bhphotovideo.com/c/product/1632736-REG

SVBONY Dovetail Base 32mm wide
https://amzn.com/dp/B07MR35HML

Posted August 23, 2022

Just doing a little weekend astrophotography

Actually, I'm just taking pictures of my gear because the evening weather is foul. But if it was clear, this is what I would be using to capture the night sky.

Posted August 20, 2022

Every ZWO AM5 Mount comes with its own Periodic Error Chart

If I'm calculating this correctly, the theoretical best performance for my particular ZWO AM5 mount with a maximum period error of 23.6" is 0.136 arc-second error for a 1 second guide duration. So, 0.136" error is what's possible with perfect seeing, no atmosphere, in Earth's orbit somewhere. Here on the ground, ZWO has specified that all AM5 mounts should perform with 0.5" to 0.8" total error or better, given average seeing and atmospheric disturbance. And that seems to be exactly what I am experiencing.

For a detailed walk-through of the periodic error report values and calculations see 10 things you need to know about the custom AM5’s PE Test Report provided by ZWO

Posted August 17, 2022

I finally bought the Optolong L-eXtreme

The weather doesn't look like it's going to cooperate in the next four to five days, and at the same time, the moon is seriously imposing its reflective properties on the night sky. So, not the best time to try out a new filter—even a narrowband one. I recently bought the Optolong L-eXtreme dual-band filter, specifically for my ZWO ASI071 color camera, which has an APS-C sized sensor. The L-eXtreme filters out everything except two narrow (7nm) bands along the Oxygen III line and Hydrogen-alpha line. I am anxious to try this out with the 8" f/4 Newtonian on the Veil Nebula.

Posted August 12, 2022

A quick note about ZWO AM5 guiding

I have been imaging the night sky for eight years with five different EQ mounts, most of it from my backyard in New Hampshire, and I rarely experience guiding this precise. I have been out imaging three nights with the AM5 so far, with reasonably clear skies and average seeing—nothing spectacular. These are some of the lowest total RMS error numbers I have seen from my Bortle 4 to 5 backyard. We're going through a stretch of clouds and rain, but hoping for better weather toward the end of the week. I'll post more guiding results along with some PHD2 logs.

Posted August 10, 2022

Cable Management Update

I nearly found out the hard way that the new ZWO AM5 mount is so compact that power and USB cables from the primary camera can easily loop over the altitude and azimuth adjustment knobs at the base and snag, something I never really thought about with a larger mount. This happened the other night, and I just managed to unhook them and continue imaging.

So, a little cable management was in order for the William Optics SpaceCat 51 on the ZWO AM5. The guide camera (silver camera on top) and the filter wheel plug into USB ports on the primary camera (ZWO ASI1600MM-Pro) at the back. Another USB cable runs from the autofocus (ZWO EAF), the red box under the scope. I end up with five cables leading down to the Pegasus Astro Powerbox and the fanless Windows 10 machine running the control software (NINA). What's new in these pics is the SmallRig Switching Plate (1598) and two of the SmallRig Spring Cable Clamps (MD2418). These are designed for cable management on cinema cameras, but work just as well for our gear.

https://www.amazon.com/dp/B08NT68D3Z
https://www.amazon.com/dp/B00X5NXSRQ

Posted August 9, 2022

Setting the Home Position for the ZWO AM5 Mount

Out of the box the DEC axis of my AM5 was a few degrees east, not lined up with the RA axis. There may be several ways to reset the home position, but I used the ASI Mount app on my phone. Plugged in the AM5 hand controller for wifi, connected to AMH_..., and when you tap the AM5 icon at the lower left, there's a "Home Position" in AM5 Settings. Tap "Calibrate" (it will move to what it thinks is home first), then you can adjust the DEC/RA with the buttons in the app (or maybe with the hand controller) and tap "Set" to save that position in the AM5.