Insect Photography Rig Preliminary Design Review Brendan Kemp

Insect Photography Rig Preliminary Design Review Brendan Kemp Rob Leveille Nafis Azad

Background and Motivation The insects kingdom is a fascinating group of organisms. An estimated 2 million species of insects exist, and less than half of those are documented. One of the difficulties of studying flying insects is their speed and agility make it difficult to draw or photograph them without capturing and killing them. This method precludes natural depiction within the habitat, removing the insect from the context within which it should be studied. We could overcome this problem if we had a camera with sufficiently fast response to photograph insects mid-flight. Such a system would give scientists the benefit of natural depictions for study. The complex and striking nature of the subject might also yield beautiful photographs.

Design Overview Available camera systems are too slow because they must calculate and set the field of view, lens aperture, shutter speed, focal length and flash timing before releasing the shutter. By the time the camera has adjusted, the insect is gone. We will surmount this problem by presetting all the camera variables. These settings will take an sharp photo of an insect around a certain point in front of the lens. Our design will detect the insect as it passes through this point and release the shutter. We will detect the presence of an insect by light-emitter photo-diode pairs. When the beam of light is interrupted, we know that an insect is present on the line of the beam. Triangulation via crossing beams of light will determine the exact location of the insect. The light beam information will be sent to a logic system that will determine the correct time to release the shutter. The logic system will send a signal to the camera body, which will release the shutter.

Design of Sensors and Frame The sensors will consist of laser-pointer and photo diode pairs. The sensors will be mounted on a frame which will be attached to the camera body. The frame will consist of arms extending from the camera body and vertical sensor mounting posts. The vertical mounting posts will allow for triangulation of the insect within the shallow cylindrical area of focus. The sensor information will be communicated via wire to the logic system.

Design of Logic and Transmitter The sensor information will be received by a coincidence circuit. The coincidence logic will go high whenever two events occur at the same time – when two beams are broken at the same time. Activation of the coincidence logic will close the circuit on an infrared (IR) transmitter, which will send a shutter release message to the IR receiver on the camera body. The camera body will trigger the mechanisms which release the shutter, capturing the insect’s photo.

Deliverables Speed of shutter response and ease of use are the aims of this project. For that reason, our deliverables will be a system that is light and simple, and capable of capturing sharp photographs of flying insects. Based on the area of capture and the likely speed of the insect, we want to deliver a system with 1/200 s shutter delay.

System Block Diagram Description text

Proposed MDR Specification We would like to be graded at MDR on the following accomplishments: 1. A sensor trip system that is able to indicate that it detects an object passing through a light beam. 2. Send IR messages via an IR transmitter interfaced to our logic circuitry. 3. Initiate a shutter trip on the camera body using the IR transmitter.