Kim2010

Excellent! I always like Maks.

Or focusing issue on the moons?

The moons are elongated as well on the 100ED image.

Hmm looks like the elongated moon is just seeing or maybe tracking artifacts. The below is Jupiter same camera, but using my 100ED 4" apo with 2X Barlow. I am sure this scope has zero astigmatism.

No matter what, this seems to be the best I can get to with the C8.

4 hours ago, dweller25 said:

Did you try any of the suggestions that were made in September ?

Yup.

Here are the latest star video and stacked image I was able to do a few weeks ago with my C8.

Raw video:

Stacked images of the video as well as an image of Jupiter are attached.

Is this level of astigmatism significant enough to affect visual and/or images with this scope?

39 minutes ago, Oldfort said:

I think a hard knock could have done this.  I had a 10" SCT which took a tumble, due to me not tightening the tripod legs enough. On one side of focus, the image was elongated vertically and the other side of focus the image was elongated horizontally.

I don't know wht the fix was because I took it back to the retailer (when they had an after sales service) but it was sorted out quickly and cheaply.

This sounds promising, but when we travel, it is always in its hard case. But still, I wish I knew what that aftersales folk did..

Thanks for the responses so far.

I am not sure if the seeing was obscuring the problem, but what I am 100% sure was that there was a night sometime in March which I remember so clearly because the seeing was so stable that I was looking at Antares at 400 and 500x and it looked like a mini-solar system with the bright Airy disc surrounded by a semi-bright first ring and then fainter rings with Antares B sitting on one of the fainter rings. I then looked at another random star with a 3mm Zoom and OMG, the Airy disc/Fresnel pattern was still as pretty. This is why I know it presented a non-astigmatic image before April.

Now since April, I was shocked when I saw the crosses at high power. I remember the only thing I changed was that I added a new finder mounting and replaced the red dot finder and also used a 6.3 reducer corrector-- which I since have removed, but the astigmatic images remain.

Now my wife and I travel a lot, and so maybe it got bumped along the way and that caused the issue?

As to what I have done so far since finding the issue, I have rotated the corrector although I did not take note of the change in orientation of the cross but it seemed not to do too much so I returned it to the original orientation. I have not yet checked the secondary and primary. I have also removed the corrector screws and just tightened them "finger tight" so to speak. 

I am curious with the thing regarding the secondary housing-- how do I check this?

And yup, this is brand new, but I don't think I can get warranty because I imported it from the US to the Philippines, and I think the warranty from the US store only applies if I were in the US.

I have discussed this at length over with folks at CN, but I am still troubled by this.

So I bought an 8SE NEW last Aug 2022, and for a few months I don't remember seeing this issue, but then around April this year, I started to visually see cross-shaped stars at high power, which sometimes vanished and focused into a proper Airy disc and diffraction ring. 

Some of the videos I took are below. Is this astigmatism in the optics? And if so how can it suddenly appear out of nowhere apparently?