Reducer 0.66x CDK20 / CDK24

Name: Reducer 0.66x CDK20 / CDK24
Brand: Planewave
SKU: 200166
Price: 1152 USD
Availability: InStock
Rating: 4.8 (5 reviews)

Reducer 0.66x CDK20 / CDK24 - Main image

$1152 ~~$1600~~ In stock

Category: Astrophotography Accessories

Description

This is a reducer designed specifically for flat field telescopes like the CDK. This reduces the f ratio of the CDK telescope 66%. The f/6.8 CDK20 telescopes will be reduced to about f/4.5.

**NOTE - 200166 adapter is also compatible with CDK17 that have 8.81" back focus. CDK17 with 10.24" back focus will use the 125166 focal reducer. See instruction manual for details.

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Customer Reviews (4.8 / 5 · 5 reviews)

Avery ★★★★★ Oct 21, 2026

The image circle on my CDK24 is noticeably flatter now, and stars in the corners look like sharp points instead of seagulls. Installation was straightforward, and the 0.66x reduction really speeds up my narrowband exposures.

Nicholas ★★★★★ Oct 20, 2026

I paired this with my CDK20 and the drop to about f/4.5 really sped up my narrowband sessions. Installation was straightforward, and the threads matched perfectly with no tilt issues.

Ella ★★★★★ Oct 19, 2026

I was worried about losing light at the edges of my images, but this reducer sharpened up the stars across the entire field. The 0.66x reduction on my f/6.8 scope makes for noticeably shorter exposures now.