# Ritchey–Chrétien imaging in a tennis court

- By: Brainandforce
- Date: 2026-04-20
- Classification: Photograph
- Museum: [Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Ritchey%E2%80%93Chr%C3%A9tien_imaging_in_a_tennis_court.jpg)
- Rights: [CC BY 4.0](https://creativecommons.org/licenses/by/4.0)
- Picture: https://upload.wikimedia.org/wikipedia/commons/thumb/6/65/Ritchey%E2%80%93Chr%C3%A9tien_imaging_in_a_tennis_court.jpg/1920px-Ritchey%E2%80%93Chr%C3%A9tien_imaging_in_a_tennis_court.jpg
- Who can see it: Tweens profiles and older (museums give no ratings; placed by Invisible Network from the museum's own words)

This is my home base for narrowband and infrared imaging. You can see me going wild with the glow-in-the dark tape on the OTA, focuser, and pier extension, to help with visibility in dark sky sites. The Milky Way can be faintly seen in Sagittarius, along with the head of Scorpius to the west.

Setup

OTA: Apertura CarbonStar RC8 (203 mm f/8 Ritchey–Chrétien)

Mount: Sky-Watcher Wave 150i (strain wave German equatorial mount)

Camera: Touptek ATR533M (Sony IMX533 monochrome CMOS sensor) with tilt plate

Filter wheel: Touptek AFW-M (8-position wheel supporting 1.25" and 36 mm filters)

Filters: Touptek 1.25" LRGB, Touptek 6.5 nm SHO, SVBONY SV183 685 nm IR pass

Off-axis guider: SVBONY SV238 OAG

Guide camera: Player One Xena-M (IMX178 version)

Focuser: Apertura rack and pinion Cassegrain focuser with Gemini electronic autofocuser

Control: MeLe Quieter 4C running NINA, GS Server, PHD2, and ASTAP

Other accessories: Z-Bolt 525 nm laser in right Synta finder bracket

Target: M27 (Dumbbell Nebula)