TS Optics Bahtinov Focusing Mask 150-200 mm
The TS Optics Bahtinov focusing mask is a simple but remarkably effective tool for anyone who wants to get the best results from their astrophotography. The plastic mask fits over the front of your telescope and lets you set the exact focus point - no guesswork, no repeated adjustments, no blurred stars in your image. It is designed for telescopes and camera lenses with an outer diameter of 150 to 200 mm.
How it works
The mask is named after its inventor, Pavel Bahtinov. The principle is elegantly simple. The mask splits the light coming from a star into three distinct lines, visible in your camera's live view. When focus is off, the central line is shifted relative to the two outer lines. When all three lines align perfectly, you have reached optimal focus. This visual indicator is significantly more reliable than any autofocus system, and it works equally well on a telescope or a camera lens.
Secure mounting
Each mask comes with three screws for safe attachment. Before fitting the mask, remove the plastic caps from the screws, pass the screws through the corresponding holes, and replace the caps. The mask then sits firmly on the tube and will not slip during use.
Step-by-step focusing guide
- Fit the Bahtinov mask over the front of your telescope.
- Point the telescope at a bright star.
- Switch your camera to live view and observe the star on the screen.
- Turn the focuser slowly until the central diffraction line aligns exactly with the two outer lines.
- Once all three lines meet precisely, focus is set.
- Remove the mask and begin your exposure immediately.
Key features
- Precise focus for astrophotography - every time
- Compatible with telescopes and camera lenses with an outer diameter of 150-200 mm
- Lightweight plastic construction
- Three-screw mounting system for a secure, slip-free fit
- Works with any camera in live view mode
- Named after inventor Pavel Bahtinov - a trusted standard in astrophotography
Technical specifications
| Parameter |
Value |
| Compatible outer diameter |
150-200 mm |
| Material |
Plastic |
| Mounting |
3 screws with protective caps |
| Recommended use |
Astrophotography - live view focusing |
Who is this mask for?
The Bahtinov mask is an essential accessory for any astrophotographer, whether you are just starting out or already have experience in the field. Achieving sharp focus is one of the most important steps in astrophotography, and this mask makes it fast, reliable, and repeatable. If you have spent time imaging the Andromeda Galaxy or the Pleiades only to find your stars are slightly soft, this tool will solve that problem for good.
