HAPPY NEW YEAR TO EVERYBODY!!!
After a long time of clouds and rain - yesterday was the first day since a while with a clear sky... - of course yesterday! just the evening everybody has other plans then startesting a new scope
When I tried the startest first time before some days I only had a small hole in the sky and brought the scope out from a warm living room to the cold night (23°C to about 2°C). Startest at this state was terrible and showed a strong spherical error (no more sure if it was over- or undercorrection) - dissapointing at first - but I hoped the correction would get better when the scope acclimates. A next proof 30min later showed just a better view but as always in such a case - after that it became cloudy again...
However, yesterday before we went out - I had the chance to do some better testing... so what did I find?
1. the scope just works very well on a lighter Great Polaris mount and don´t need the DX version - great!
2. the socpe really needs its time to cool properly to show it´s great optics (took it out about 1,5h before watching without using the fans)
3. when cooled - startest is near perfect - just as good as I found it with my earlier ETX90 and ETX125. This means identical looking ring patterns intra- and extrafokal at mags up to 650x and a clearly visible airydisc with diffraction ring.
4. at highest magnifications I could see a very, very slight triangular astigmatism when looking at the first diffraction ring around the ariydisc. It looked like the ring has three slight light-breakaouts symmetrical at 120°. As its absolute symmetrical I guess it´s from the fixture screws of the meniskus lens that are maybe a bit too strong. But as it´s so minor it will not have any effect at "normal" use and I´m confident it could be completely removed with a little bit optimization.
5. mirror shifting while focussing is so small it really is negligible - just at 650x you have to look very keenly for it to find a very slight moving of the image when changing the focusing direction - no comparrision to my earlier C9,25 from which I just thought it was good at this point.
6. just with the secondary baffle installed I got some ugly reflexions when looking at objects close to the moon - but that was for testing only and should be normal.
So I´m very happy with this buy - incredible how much scope you can get for a very reasonable price! Looking forward to do some comparrisons with this scope against some 5" and 6" apos...