Dark Clear Skies M54M to M42M Back Focus Spacer – 2mm wide field telescope Black anodized finish

Black anodized finish

Calcium K-Line and Calcium H-Line in one dualband filter

which provides excellent colour correction and reduces chromatic aberration

EMH150 Pier Extension

this adapter is commonly used in advanced astrophotography setups involving reducers

Dark Clear Skies M54M to M42M Back Focus Spacer – 2mm wide field telescope Black anodized finishThe Dark Clear Skies M54M to M42M Fine Back Focus Spacer (2 mm) is a precision machined spacer designed for accurate fine adjustment of back focus distance in astrophotography imaging trains. Purpose & Use Many telescope reducers and field flatteners require very precise back focus spacing to deliver optimal star shapes and edge correction. Small spacing errors of just a few millimetres can noticeably affect image quality, particularly when using fast