TS Optics M90/M90 Tilt Adapter
You know that moment - the stars in the centre of your image look perfect, but in one corner they stretch into streaks or ellipses. This is the so-called "bad corner" effect, and it affects almost every astrophotographer at some point. The cause can be a slightly tilted optical path, an imperfect focuser, or a camera sensor that the manufacturer mounted with a small offset - too small to matter for everyday photography, but too large for the demands of high-resolution astrophotography.
The TS Optics M90/M90 tilt adapter solves this problem systematically and permanently. It works by gently tilting the camera's attachment plane relative to the optical axis of the telescope - by exactly as much as needed, and in exactly the right direction.
How it works
The adapter features three adjustment screws that allow precise tilting in any direction. Once you find the position where stars appear sharp and round even in the far corners of the frame, you lock it in place with the locking screws. The setup process takes some time, but you only do it once. After that, the position stays stable.
It is recommended to keep the orientation of the adapter and the camera sensor consistent between sessions. Rotating one relative to the other will require you to repeat the alignment process.
Use with refractors
The TS Optics M90/M90 also works well for improving entry-level refractors. Many affordable refractors have good optics but offer no way to adjust the collimation of the objective lens. By placing this tilt adapter between the objective lens and the tube, you can tilt the lens and align it precisely to the optical axis of the tube. You will need a suitable adapter from your lens mount to the M90x1 thread, and a matching adapter on the tube side. It is an elegant solution for custom optical adjustments and upgrades.
Setup tools required
Adjusting the adapter requires two hex keys - 3 mm and 2 mm. These are not included in the box.
Why this matters for large sensors
A tilt adapter for astrophotography is a one-time investment in image quality. The larger your camera sensor, the more visible the corner distortion becomes - and no software correction fully replaces a correctly aligned optical system. If you are working with a full-frame or large-format sensor, this adapter is one of the most effective tools you can add to your imaging setup.
Technical specifications
| Parameter |
Value |
| Thread - camera side |
M90x1 |
| Thread - telescope side |
M90x1 |
| Number of adjustment screws |
3 |
| Hex key sizes required |
3 mm and 2 mm (not included) |
| Application |
Camera tilt correction, refractor objective alignment |
