SVBONYSV555 Telescope-New Upgrade, Precision Focus Zero Compromise, Astrophotography Telescope 54mm APO Refractor SLR Camera Lens, 44mm Full Frame, F4.5 to F22 Variable Aperture for Astrophotography

This lens produces pin-point star images with no visibly noticeable aberrations across the entire full-sensor (36x24mm) image field. Vignetting is minimal. The manual focus ring is outstanding and easy to use with designed option for electric focuser mount. It is difficult to imagine a more perfectly designed astrograph for wide-field astrophotography.

No, Sbvony made the adapter too long and you can't achieve focus at infinity wo a filter. They fixed this with newer model giving a smaller adapter. Problem is how do you know if your buying new or older sv555 with the issue.

This is my first telescope, so I don't have much to compare it to. That being said, I'm very impressed with it thus far. The stars are sharp, and I haven't noticed any strange chromatic aberration issues that so many of the YouTube reviewers warned of. My only complaint was that I cannot seem to get perfect focus unless I am using a 2 inch filter. I think the backfocus must be a little longer than 55mm. I am using the SVBony filter drawer, which gives me perfect focus when a filter is installed, but it's worth mentioning for those who don't plan to use a filter. I love how you can lock the focus ring and aperture ring. Makes setup very quick and easy once you find your target. I'm very happy with the telescope.

Couldn't not achieve focus.

This scope is actually a great design. One of the reviewers complained that it would not reach focus, I believe that reviewer does not understand that this is designed for Astro photography and will not achieve visual focus without extension added.