A cycloidal diffractive waveplate based star simulator generates a star field with very high precision star locations and accurate brightness. The present disclosure provides a star simulator that allows for a large FOV, modular, multi-star simulator capable of very high precision dynamic star locations for testing of high accuracy, large FOV star trackers. The system is composed of a light source, a polarization grating-based image [1], and an opto-mechanical system for steering the light. The light is projected onto a diffuse screen where the light is scattered, creating a functional point source at the screen. A star tracker or other device under test views the screen which has a multitude of projected spots (each with its own light source and beam steering device) positioned in a star field distribution appropriate for the simulated viewing direction.

An image forming apparatus including an image forming unit, a fixing device, and circuitry is provided. The image forming unit is configured to perform a special image forming operation that forms a color toner image and a special toner image with a color toner and a special toner, respectively, on a recording medium and a normal image forming operation that forms the color toner image without forming the special toner image on the recording medium. The fixing device is configured to fix the color toner image and the special toner image on the recording medium. The circuitry is configured to perform, in the special image forming operation, a toner amount suppression control that makes an amount of the color toner on the recording medium per unit area smaller than that in the normal image forming operation.

In an aspect, a device-and-clip system is provided for an electronic device. The system includes an external device that cooperates with at least one electronic device feature on the rear face to perform a selected function. The system includes a clip including a first clip arm having an arm marker thereon and which is engageable with the front face of the electronic device and a second clip arm that is engageable with the rear face of the electronic device. The system further includes an application that is executable to instruct the electronic device to display a screen marker on the display screen in a selected position and in a selected orientation such that positioning and orienting of the first clip arm on the display screen of the smart phone with the arm marker aligned with the position and orientation of the screen marker positions the external device in alignment with the at least one electronic device feature.