I decided to build a new astrophotography setup which would be fairly fast. The system needed to be simple, and something you could easily collimate in the field. I realized that a f/4-f/5 newtonian would be perfect for this task, and a starizona nexus CC could make it even faster. I eventually decided on a GSO 8" f/5, because the design was simple, it could upgrade it in the future (lots of common parts for it), and with a nexus CC, I could bring the focal length down without having a bigger secondary obstruction. But more importantly, GSO's supposedly had decent optics for the price; it was not supposed to be amazing by any means, but it gave room for more important additions (like new focusers). The previous setup I was building was a slow one, and this would be the exact opposite. For the slow setup, I used a canon 6D, but for this setup I would need a different camera, so I pre-ordered Player Ones Ares-C, which is the new version of the 533mc camera. I chose that camera because the "decently" illuminated field only covered 21mm at F/5, and at F/3.75 (after installing the CC) would reduce that down to around 16mm, which is the diagonal of a 533mc. And the pixel size of the 533mc was big enough to not severely undersample at F/3.75, although it could be better; the tradeoff is speed of course. I figured drizzling could be used when exposure time was not an issue.
So this was kind of my philosophy when going into the setup. It could start out doing the bare minimum as a fast system, and as it was tested, it could be upgraded or transition into more of a DIY project down the road.
I chose Agena Astro, because I heard they had a "decent" reputation, and they were the few ones who had GSO telescopes in stock, as there continues to be a shortage. I later found Agena to NOT live up to their reputation for newtonian telescopes, and more is explained further in this story. I went ahead and purchased the telescope on May 13th, 2023. I had purchased the other items shortly before that. The starizona nexus came directly from starizona. Everything seemed to arrive on time, and I was pretty happy that things were lining up. Of course, the player one camera was pre-ordered, so that would be a longer wait.
When I opened up the telescope, everything made sense and I could not see any obvious defects or damage on the outside of the unit. Either GSO or Agena had installed the mirrors, the primary mirror cell, the spider, and the focuser. Everything except the rings and 50mm finder were put together, and I heard that some companies do not do that with newtonians.
The rings seemed a bit heavy and wobbly at the hinge, but they seemed functional.
The telescope has an extreme amount of friction in the bottom ring, so rotating it in the field will be challenging. For visual use, this would be a big problem. The telescope came with a signed certificate claiming it was optically tested. This was another benefit of going with Agena Astro, but they don't give any numbers so the testing is not that meaningful, other than there is nothing glaringly obvious with the mirrors.
The telescope basically popped into the bottom rings, and I was able to clamp it down. The issue I had was since there is so much friction in the bottom rings, its hard to determine how much you have clamped down the top rings. The only way I found to gauge that the top rings are clamped down enough is by trying to wiggle them along the axis of the tube. If you cant wiggle them anymore, there should not be too much play. Putting the finder into the ring bracket was a bit tricky without scratching it up, an O-ring has to go into a forward gap, and this is forward support. You have to push down on a spring supported cylinder to slide the ring bracket onto the rear gap, which is where you could accidentally scratch the paint on the finder; I fortunately did not.
When sliding the finder into the shoe, tightening down the screw will be a bit wonky.
It never feels like its tight enough, and the entire bracket sort of ends up going where its going to go as you tighten it down; it seems like a second screw is necessary, and a set screw seems to take the place of where a second one could optionally go.
Everything on the outside looked great. Functionally, the focuser was smooth and didn't seem to have any obvious issues.
This is where things go down hill. The optics seemed ok, but they seemed dirty to me.
The collimation springs on the primary would need replacing, but that was obvious and a known issue.
The real issue was the horrific internal paint job. There was way too much loose paint, and it was like a dust.
This was specifically talked about in another thread, so I won't go into too much detail, but suffice to say it risked getting all over the mirrors and cleaning it off would be a pain and could void the warranty. Its possible that the optics may have more than normal dust on them already, so they might need a careful cleaning.
The spider assembly seemed sturdy and centered.
I've heard some rumors that the spiders are not that good, or the secondary has issues, but the secondary mirror is adhered onto its base so I don't see how mirror pinch could be an issue. The primary mirror has a donut already on it, so precise collimation wont be a problem either, but those springs would of course need to be replaced.
I reached out to Agena Astro to figure out the best way to handle the paint issue. Rather than going through an exchange process or their own recommendation, it went straight into the warranty process. However, GSO claimed that the paint issue was normal, and after that Agena refused to acknowledge that this was an issue. Instead, they gave me possibly warranty voiding advice of scrubbing out the paint in the tube with isopropyl alcohol, which would only be sensible with a used item, or an item someone would have had for much longer and chose to flock.
Date TBD. I will post to this thread.
All in all, it was a great design ruined by a careless painter, bad quality control, and two companies which seem to transcend normal human desire. I will probably do one field test run and post the results at a later time, but I figured it would be beneficial to post this ASAP. I think this could be an incredible astrophotography setup, especially for a beginner, but I think there are too many issues that would scare away a beginner. In fact, I don't recommend this at all for visual use unless you get different rings. The paint issue is possible to fix, but its not really fair for a new scope under warranty, and I don't think a beginner would be comfortable going through the entire process.