The supplied 2" adapter tube is shown to the left of the main body of the OAG. Internally there are stepped retainers and set screws to hold the large diameter focal reducer also available from Lumicon. The focal reducer is at the top right. This focal reducer can be adjusted to several positions and is a full 80 mm in size. ASTRONOMY. ENCYCLOPEDIA ASTRONOMY ENCYCLOPEDIA FOREWORD BY LEIF J. ROBINSON Editor Emeritus, Sky & Telescope magazine. STAR MAPS CREATED BY WIL TIRION. GENERAL EDITOR SIR PATRICK MOORE HOW TO USE THE ENCYCLOPEDIA PHILIPS ASTRONOMY ENCYCLOPEDIA First published in Great Britain in 1987 by Mitchell Beazley under the title The Astronomy Encyclopedia (General Editor Patrick Moore) This fully Maintaining SCT Collimation; SCT Collimation Article Lumicon Giant Easy Guider (Off-Axis Guider) Meade f/3.3 vs. Optec Maxfield; f/6.3 Spacing LX200 Image Magnification; ST-7E/ST8E Guide Chip F/3.3 Focal Reducer Lessons; Re-Assemble f/3.3 FR CCD Imaging-- Single Exposure vs. Stacking Celestron 2 Inch Telescope Diagonal with XLT Coatings for SCT Telescopes Price $215.95 Sale $149.95 Customer Score: Celestron f/6.3 Focal Reducer / Corrector Lens Price $212.95 Sale $144.95 Customer Score: Losmandy DC14 Dovetail Plate for 14 Inch Celestron SCT Price $130.00: Lumicon Giant Easy Guider Adapter Ring for Celestron Price $81.00 I've used many OAG over the years and the best was the old Lumicon Giant Easy Guider. Not suited to every scope, but great on SCT's. looks like it accommodates their focal reducer. I had to get an additional 2 adapters to apply mine on my setup. 30-03-2018, 01:01 PM. My logic in the smaller prism is that you get less light, and lower Lumicon 2 Inch Prime Focus Camera Adapter drops into a 2″ telescope eyepiece holder and presents male T-threads (42mm x 0.75mm) for T-ring attachment. For prime focus photography where back-focus is not critical, and for variable focal reduction on Lumicon's Giant Easy Guiders, Giant Focal Reducers and Cassegrain Rich-Field Viewer. I know Stricker used the Lumicon Giant Easy Guider, but I don't want the off axis ability nor the additional expense that comes with it. I like the sound of Steve Moggs one. Anyone heard any reviews on it. Gamma if the Next Gen is an SCT reducer for f/10 and works with the orion, what are your thoughts on the current Meade focal reducers? Lumicon 'Giant Easy-Guider' can be used as a focal reducer to f/7.1. Focal length 2520mm. In this configuration the field of view on the Kodak KAF8300 chip used in the SBIG 8300 CCD camera is 24.7'x18.7'. The Starizona HyperStar kit converts the original SCT optics to something akin to a Schmidt telescope configuration. The Lumicon GEG utilizes an 80mm focal reducing lens that can be repositioned in the guider to allow for imaging at four different f ratios: f/10 (no focal reducer), f6.5, f/5.5, and f/4. It is a precision-built, very rugged device with many features. An excellent tutorial/overview of its features by Philip Perkins can be found here. Lumicon 2 Inch Prime Focus Camera Adapter drops into a 2" telescope eyepiece holder and presents male T-threads (42mm x 0.75mm) for T-ring attachment. For prime focus photography where back-focus is not critical, and for variable focal reduction on Lumicon's Giant Easy Guiders, Giant Focal Reducers and Cassegrain Rich-Field Viewer. - Televue .8 focal reducer for photography