Skywatcher Esprit 150ED Observatory Flap Panel (OFP2)

OFP2 PRO Motorized Observatory Flat Panel

Flat-frame acquisition should be simple, reliable, and easy to automate. The OFP2 PRO motorized observatory flat panel is designed to make flats a seamless part of your imaging workflow, without improvised solutions such as LCD screens, T-shirts, or the morning sky.

Unlike traditional designs, the OFP2 PRO moves sideways, which means it does not increase the total length of your setup and does not require additional clearance space behind the telescope to operate. This makes it especially well suited for observatory and permanently mounted systems where space efficiency matters.

During imaging, the panel remains neatly positioned beside the refractor tube. When your session is finished, it simply slides sideways into place and switches on the dimmable LED light to capture flat frames. Brightness can be adjusted to match your camera settings, gain, and filters for consistent results across different setups.

To improve reliability in humid conditions, a dew heater behind the LED panel is now included free with all of our motorized flat panels. It helps remove moisture from the LED surface and reduces the risk of dew being trapped against the OTA when the panel is closed after the session.

The new OFP2 PRO generation also brings a number of practical improvements based on customer feedback. These include improved sealing performance, refined mechanics, improved hinge design, and compression rings customized for your telescope with improved design and swappable inserts. Combined with upgraded electronics and advanced control features, the OFP2 PRO is built to deliver a cleaner, more reliable, and more convenient flat-frame workflow for automated imaging systems.

Whether you are building a fully automated observatory setup or simply want a more elegant and compact way to capture flats, the OFP2 PRO is designed to make your routine faster, easier, and more dependable.

Features

• New OFP2 PRO design for telescopes up to 6″
• Sideways-moving panel design with no added setup length and no rear clearance requirement
• Compression rings customized for your telescope, with improved design and swappable inserts
• Customizable inserts with notches for heater cables
• Storage cover
• Improved hinge design
• Better sealing performance
• ARM Cortex processor for improved performance and connectivity
• Cross-platform control panel for Windows, Linux, and macOS
• Easy installation with no bolts, 1x hand-tightening knob, and no fiddly zip ties
• Dimmable LED light
• Built-in LED heater behind the panel to prevent dew accumulation (included)
• Servo motor with encoder and improved mechanics
• High brightness selection resolution, 12-bit (0–4096)
• Manual control button
• Built-in magnets for secure open and closed positioning
• Custom open position (disabled by default)
• Integrated obstacle detection
• Automatic range calibration
• ASCOM support with automatic port detection, up to 6 concurrent devices
• INDI support
• ASIAIR / AIR camera support (ASIAIR Pro and ASIAIR Plus supported with optional cable; planned compatibility for ZWO AIR cameras and ASIAIR Mini)
• Bahtinov masks, star masks (optional)
• PC connectivity via USB-C cable (included)
• Power requirements: 12V 3A (not included)

For additional details, please see our YouTube video or user manual.

Dimensions

We are currently offering the following 6 different categories of flap panels:

Installation

Installing the observatory flap panel is straightforward and somewhat arbitrary, though a few tips can help optimize its performance. First, open the panel about 90° and slide it onto the dew shield so that its front of the compression ring aligns with the front edge of the dew shield, facing the mount saddle. For best results, ensure the panel is symmetric along the declination axis (see photo 1 below). This alignment maintains telescope balance, keeps the guide scope’s typical view unobstructed, and prevents the panel from colliding with obstacles during mount movement. Secure the panel with a hand-tightened bolt—avoid over tightening to prevent cracking the plastic—and close it before powering up.

Additionally, when the telescope is parked—especially with the larger 8″ and 10″ models—try to make sure the panel is not tilted toward the ground, preventing unnecessary flexing and allowing the magnets to snap it shut effectively (see photo 2 below). If you wish to reverse the opening direction, simply reposition the limiter on the compression ring to the other side and recalibrate the panel.