SCA Field Flattener
SCA Field Flattener


SCA Field Flattener

Regular price
$ 175.00
Sale price
$ 175.00
Unit price
Only 1 Left!

In Stock


  • High-Quality Engineered Optical Flattener
  • Built-in Self-Centering Adapter
  • SCA Eliminates Drawtube/Visualback Slop
  • SCA Eliminates Unstable Thumbscrew Locking
  • SCA Accepts the Imperfraction of a Drawtube/Visualback
  • SCA Damps Vibration from the Telescope
  • Accepts 2" Filter Thread


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 accommodates f5 to f8 refractor telescope. You will see bright and sharp image across the entire field.

SCA Accepts the Imperfections and Eliminates Drawtube Slop

When a standard collimator is inserted, the gap between the drawtube and the inserting device creates a certain degree of slop, which is a problem. All drawtubes have manufacturing tolerances, but other imperfections, like dents, scratches, uneven burrs, or even distortion can be compensated for by the rubber rings which will faithfully centers HoTech accessories in the tube every time. The rubber rings in the HoTech SCA expand radially, according to the user’s adjustments, filling the gaps. This makes your accessory seats firmly in the drawtube for a secure installation every time.

SCA Eliminates unstable locking from thumbscrews or compression ring and Keeps Laser Perfectly Parallel to the Focuser

The patented multiple expanding O-rings design provides solid, even, 360 degrees grip to the inner surface of the focuser. This keeps the accessory perfectly parallel to the focuser tube thus eliminating any possible tilt error from the conventional thumbscrew locking mechanism. When an accessory is locked down by thumb screws, the optical axis can shift. In some cases, a compression ring can cause unstable tilt when there are loose tolerances between the compression ring, inner groove, and the uneven tip of the thumbscrew(s). The SCA to the tube without using the thumbscrews or a unified compression ring.

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 back focus 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!



Fully multi-coated two-element high efficiency flattener lens
Accomodates f/5 to f/8 refractor telescopes
Zero reducer
2" SCA Adapter for a secure fit in focuser
Accepts 2" / 48mm (M48-P0.75) filter thread
Standard T-thread for most imaging cameras attachment
Back focuse distance requirement is 55mm
- from the shoulder of the T-Thread on the flattener to the surface of the CCD chip
Download the User's Manual for your review.

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