I have been thinking about a low-profile method for warming up the main scope and guide scope, and Polyimide film heaters seem like the perfect candidate. They're very thin, adhesive backed, and come in voltages (12v dc) and max output wattage that seem perfect for dew control. These aren't new in astrophotography. I know ZWO uses a Polyimide heating ring dew heater for the front of their cooled cameras, and I am pretty sure Deep Sky Dad uses similar film heating for the built in dew control on the motorized telescope cover and controllable flat panel available for some William Optics, Takahashi, and Askar scopes.

The build for this is relatively simple. I cut up an old stereo + video RCA cord, using the red and white male end audio jacks. I soldered the two leads from the jacks to the two leads from the heater film, covered the splice with shrink tubing, and that's it. I plugged both into the Pegasus Astro Pocket Powerbox to get a sense of where to set the PWM dial for best dew control results. It turned out to be quite a bit lower than expected.

CAUTION: The dew heating range in the Pocket Powerbox is 0 to 255, and I normally run my dew strips somewhere near maximum. You have to be careful with the Polyimide film though, because these generate a lot more heat, maybe enough to damage some scopes. After a couple tests, it seems like a range of 30 to 75 works. The next step is more testing--soon as the night skies clear up!

• RCA Male Jack, two leads stripped and ready to solder https://amzn.com/dp/B081TYCKC6
• Polyimide Film 12V 12W with adhesive back https://amzn.com/dp/B076PD7TXW
• Deep Sky Dad: Automated, flap panel https://shop.deepskydad.com/product/wo-redcat-flap-panel-fp1
• ZWO Anti-dew heater https://astronomy-imaging-camera.com/product/anti-dew-heater

Posted August 21, 2022

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

Here's the Tulip Nebula (Sh2-101), top center, and some of the surrounding cloud structure in Cygnus. This is 23 x 240 second (4 minute) exposures in Hydrogen-alpha (6nm Astronomik narrowband filter), no calibration frames. I'm still testing out the new ZWO AM5 mount, and the Tulip is a nice deep sky target for Ha. Gear notes: William Optics SpaceCat 51 Apo refractor, ZWO ASI1600MM-Pro cooled monochrome camera.

Posted August 20, 2022

1. The ASI Mount mobile app is a tool you should explore - I installed the ASI Mount app on my iPhone a week before the mount arrived (yeah, I was a bit excited). ZWO provides the application tools you need to configure your AM5 and keep its internal software (firmware) up to date. Use the ASI Mount app on your iPhone, iPad, Android phone, or tablet to set or adjust the AM5's home position and other settings. The app is built around a beautiful night sky observation view with full search functions, using your location to show what’s above you at the moment. Seriously, take a few minutes to check out the sky in the ASI Mount app, zoom in, find your favorite deep sky targets. A really impressive amount of design and engineering went into this. To use the app, plug in the hand controller, connect to the AM5’s wifi hotspot, named AMH_xxxx where xxxx will be an ID or random number for your mount. Links: Android (Google Play: https://bit.ly/3T29A5l), iPhone, iPad (https://apple.co/3dFhn8W) 

2. Two words: cable management - watch your loose cables on the AM5. This is a very compact and powerful mount—always keep the power of this mount in mind. There are no clutches to slip. The gearing is always engaged, and if you snag your camera’s USB and power cables on the altitude adjustment knob, the mount can easily pull those out. If you don’t have fancy cable clips, I always recommend picking up a roll of 1 inch wide gaffer tape—I mean the more expensive cloth stuff that will hold things down but won't leave any residue. Get the real thing, not the cheap stuff. I use gaffer tape to hold cables together, to tape cables to the mount or the side of a camera. It's as permanent as you want it to be, holding whatever you need to hold until it's time to tear down your gear. Then it just peels away, and you can reuse it. There are many sources for this, but here’s what I have purchased from Amazon: https://amzn.com/dp/B00DVCFFI6 

3. Start with a clean slate for guiding - In PHD2, in the ASIAir app, or whatever app you’re using for guiding in your astrophotography system, begin your first session by clearing the calibration. Slew to a nice star near the meridian and about halfway toward the zenith. The ideal point is where the meridian meets the Celestial Equator. (If you are in the northern hemisphere slew to the southern meridian; in the southern hemisphere slew to the north). Run calibration in your autoguiding application or application module—let it run and build up the data to tune your system for better guiding. It takes a few minutes away from imaging, but in my experience, it’s always worth it. 

4. The ZWO AM5 community and ZWO product information - There is already a lot of information out there, and the experiences with the AM5 grow every day. If you use Facebook, I highly recommend joining the ZWO AM5 Mount Users Group (https://bit.ly/3QCem7S). There are new posts of set ups, AM5 questions, with a lot of participation from the community. Or go to the source: ZWO has produced a full AM5 manual as well as quick guides for general operations and other products, which you may also have. Take some time to review the AM5 page on the ZWO site (https://bit.ly/3NVBufW). As of this writing, there are 131 items on the AM5 Q&A page, and the product page itself is long, with mount specifications, information on strain-wave gearing, periodic error measurements, mount features, mechanical diagrams, and more. For those who want to dig into their AM5’s periodic error report, “10 Things to Know About the PE Test Report” (https://bit.ly/3NmOzPk). And here's the ZWO Youtube Channel https://www.youtube.com/channel/UCAmDsyAh8Y0BeCN2Gs5pxrg  

Posted August 18, 2022

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

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

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

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