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I started my journey down the rabbit hole in December 2023 by ordering the first part of my astrophoto equipment, the Sky Watcher – Star Adventurer GTi. An ASIair and an auto-guiding setup soon followed this.
Since then, I have started to find my way back to my astronomy roots. This has led me to the big decision to buy a new mount. Having spent quite some time researching the marked, I went for the AM3 strain wave gear mount from ZWO.
Comparing mounts
Since I started astrophotography, I have always thought that I would give in due to the complicated nature of setting up the mount and getting everything balanced. This often took quite a while on the old Star Adventurer GTi.
In comparison, the AM3 mount is so easy to set up, not having to balance anything, just makes my life so much easier. To be fair, let me start by stating that the two mounts are at completely different price points, and some might add incomparable. The reason I originally went with the Star Tracker, the Star Adventurer GTi, was that I wanted to utilize what I already had in my inventory.
Besides this, the GTi was very cheap and got me started. But I very soon came to realize that this hobby brought up something in me that I have not been doing since I was working at the Nordic Optical Telescope in 2009.
As mentioned, my collection of equipment started to grow first with the ASIair mini and a guide scope, then my old telephotolens was replaced by the Askar 71F Flat-Field, due to massive chromatic aberration. Finally, I gave in and bought an ASI533MC Pro dedicated cooled astrophotography camera. At this time, my OTA with camera, guide scope, ASIair cables, etc. weighs approximately 4.5 kg.
Which is just 500 g short of the GTi’s payload limit of 5 kg. This is also partly the reason I had a hard time balancing the mount, as the counterweights needed to be shifted further down than the length of the counterweight bar. My conclusion was that I needed to get a new mount, I went with the ZWO AM3 mount since it suited my needs.
Star Adventurer GTi vs. ZWO AM3
It is time to compare the mounts – let’s see what we can make of it.
Star Adventurer GTi
This mount was bought as a set with a pier extension and a tripod included for around 750 euros. At first glance, the tripod seems a little flimsy, and the mount itself weighs just shy of 3 kg, without the counterweights. With the counterweights installed, the mass of the mount head is around 6 kg.
The saddle for mounting your telescope is a Vixen style saddle with only one screw to hod your telescope in place, this have had me watching my scope with axiousness more than once. Like wise the system for attaching the mount head to the peir extension, with only three small screws have had me worried more than once, as they tend to contract a bit as the temperature drops.
You can get the Star Adventurer GTi from astroshop.eu. This is an awesome mount for starting in this hobby. Its main selling point is that it has a very low power consumption; you can power it from 8 AA batteries. And, of course, it is fairly cheap.
ZWO AM3
I bought this mount with just a carbon tripod for portability. The price point for this mount, incl. the tripod ,was around 2200 euros. This seems very expensive, and to be honest it is. The build quality is excellent and not having to balance everything every time is worth all the money. The mount head have a mass just short of 5 kg, and support 8 kg of telescope without a counterweight and 13 kg with a counterweight.
The saddle is a combined Vixen and Losmandy style saddle, with two spring-loaded clamps to hold the telescope in place. This mount and the tripod have changed the way my astrophotography work. It has become far easier to set up in the evening
The overall mount is sturdy and I consequently have guiding that is a factor of two better than the GTi mount. I am now always below 1″ RMS on the guiding, where above 1″ was more the common value of the GTi. Hence I am able to make my exposures longer, from 120 – 180 second I can now easily do 300 second exposures. As always you can find my current equipment in my equipmentlist
Image quality
As usual when you acquire new equipment the weather, take a turn for the worse, and this was no exception. But I had a few clear nights to test the AM3. I tested it on M51 that are fairly high in the sky. The image below was recorded in subs of 300 seconds over four nights, the total exposuretime was approximately 7,5 hours.
