Reverse lenses

The reversing lens (Erectorexplained

• Upright image: essential for terrestrial use, photography of bird and landscape observations.

• Mechanism: A compact lens system that corrects the image, often integrated into refractor accessories.

• Advantage in EAA: Combine with a camera for live images captured upright, without reverse orientation.

Build quality and coatings

• Glass: Choose ED or FPL glass in your Barlow for minimal chromaticity and depth of field.

• Coatings: multi-coatings >98% transmission, protective fluoride coatings for scratch resistance.

• Mechanics: CNC-machined aluminum housing with Delrin collar for smooth and secure mounting.

Backfocus & Installation

1. Backfocus check: Beforehand, measure your total chain length (including Barlow + eyepiece + diagonal) on a flat surface.

2. Focuser Adjustment: adjust tension or clamps to compensate for extra weight.

3. Photography: Test your frames for sharpness and stellar detail; small adjustments in the clamp mount can make a world of difference.

6. Use tips for optimal results

• Start with standard eyepiece + 2× Barlow: learn about typical magnifications.

• Pair with a star diagonal: Maintain a straight line of light and avoid reflection.

• Avoid stacking multiple Barlows: leads to more aberrations and light loss.

• Use a fine focuser or motor focuser at high magnifications to avoid backlash.