Hotech SCA Field Flattener 2"

HOTECH SCA Field Flattener Patented

High Quality Optics Designed for Refractor Telescopes

This field flattener is fully multi-coated on two-element lens allowing the most efficient light transmission without sacrificing the precious collected light from your telescope. It accomodates f5 to f8 refractor telescope. You will see bright and sharp image across the entire field.

Image of VEGA is taken with Takahashi TSA-102(F/8) using a Canon SXi DSLR.
Stack of 4 x 5 min exposures without sharpening or noise reduction.
* Note the enlarged star at the right edge of the photo.  The star remains circular.

Photo taken by Dennis di Cicco and image processed by Sean Walker of the 2009 Easter Island eclipse.

The exposures were made with a Nikon D700 camera at ISO 200, using a 600-mm f/7 refractor and a HoTech field flattener. Read technical details at our Photo Gallery. 

SCA Brings your Camera to the Closest Optical Axis in the Drawtube/Visual back for BEST Imaging Result

To capture great images from your telescope, it is essential to position your camera firmly in and on the optical axis of your drawtube/visual back. The SCA T-Adapter center loads your camera in the drawtube/visual back with a simple threading of a compression ring forcing the built-in rubber rings outward radially, thereby centering the camera in the drawtube/visual back for optimal installation.

SCA Eliminates Drawtube/Visual Back Slop

All drawtube/visual back have manufacturing tolerances.  And it requires larger diameter to accept various eyepieces and adapters.  When the camera adapter is inserted, the gap between the drawtube/visual back and the inserting device became a slop problem.  The rubber rings in the SCA expand radially according to users own adjustment to fill the gaps.  This makes your camera seats firmly in your drawtube/visual back becoming part of your telescope for a secure and repeatable installation.

SCA Eliminates unstable locking from thumbscrew or unified compression ring

The optical axis is shifted when the inserting device is locked in by thumbscrew.  In some cases, some poorly made unified compression ring can cause unstable tilt when locking in the drawtube due to loose tolerances between the compression ring, inner groove, and the uneven tip of the locking thumbscrew in a drawtube.  The SCA T-Adapter adapts your camera without using the thumbscrew or the unified compression ring.

SCA Accepts the Imperfection of a Drawtube/Visual Back

Small imperfection inside the drawtube like dents and scratches, the rubber rings fill the gaps and faithfully centers your camera in the tube.  In addition, even if the drawtube is slightly deformed in diameter, egg-shape, the rubber rings in the SCA will compensate the differences and faithfully centers your camera.

Short SCA Profile Prevents Oscillation

Short profile design keeps the installed camera stable from low frequency oscillation transferred from the telescope in a windy environment.  The non-reducer flattener's back focuse distance, T-Thread shoulder to the CCD chip, requirement is 55mm.

SCA Damps Vibration
The all-around adjustable tightness rubber contact damps unwanted vibrations from the telescope provides you a sturdy attachment on your telescope for a stable image capture.

The 2" Field Flattener Accepts 2" Filter Thread

SCA Field Flattener has built-in standard 2”/48mm (M48-P0.75) filter thread. T-ring thread accepts all kinds of 35mm cameras.

It is yet another dream come true for imagers!