TS Optics Flattener/Reducer 0.8x (85704)

This flattener is a lens designed to correct the field curvature caused by the primary optics of a telescope. Field curvature can make stars at the edge of the image appear less sharp. The flattener, or field flattener, corrects this issue, resulting in sharp stars all the way to the edge of astrophotography images. It is installed between the telescope and the camera.

The reducer function shortens the focal length, which improves the aperture ratio of the telescope. This means shorter exposure times and faster optics. The field of view is also increased, making it possible to observe or photograph larger astronomical objects.

A key feature of this corrector is the built-in fine adjustment mechanism. By turning the knurled ring, the distance to the sensor can be adjusted precisely in fractions of a millimeter. Once the correct distance is set, it can be fixed with a clamping screw. This allows for optimal distance adjustment with the camera attached, using test shots, and without the need for extra adaptors or rings. The camera remains stationary during fine adjustment.

Recommended sensor distances from the innermost adjustment position:

• 102 mm aperture, f/7: 55 mm

• 80 mm aperture, f/7: 57.6 mm

• 80 mm aperture, f/6: 59.6 mm

• 70 mm aperture, f/6: 61.6 mm

Example:
For a refractor with an 80 mm aperture and f/6 (480 mm focal length), and a DSLR camera with a 55 mm distance from the M48 thread to the sensor:
The required working distance is 59.6 mm. Subtract 55 mm (camera distance) from 59.6 mm, which leaves 4.6 mm.
Extend the adjustment mechanism outward by 4.6 mm using the distance marks. The system is now at the optimal distance for imaging.

TS Optics is a brand of Teleskop-Service.

Specifications

• Connection to telescope: M63

• Camera connection: M48

• Number of lens elements: 3

• Focal length reduction: 0.8x

• Optical length: 65 mm

• Optical coating: Multi-coated

• Filter thread: Yes

• Suitable for telescopes: 70 mm to 102 mm with focusers larger than 2.5"

• Fully corrected field: 42 mm

• Fine adjustment: Yes

• Type: Flattener, Corrector, Reducer