CFHT Information Bulletin, number 39, Second Semester 1998

MegaPrime: A new Prime-Focus Environment and Wide Field Image Camera

Christian Veillet, Resident Astronomer, MegaPrime Project Manager (

1) Overview

MegaPrime is one of four major projects undertaken at CFHT in the frame of the 1996-2001 Instrumentation Plan, together with KIR, a 1k x 1k IR array, CFH12k, an 8k x 12k wide field CCD camera for the existing prime focus environment, and CFH-IR, another 1k x1k IR array to be used on OSIS, the Optionally Stabilized Spectrometer and Imager. MegaPrime is, by its budget, its duration and the number of people involved, the most ambitious of these new instruments; it's a new environment with a new detector which should be available on the telescope in mid 2001, the planned date of completion.

The new prime-focus environment of MegaPrime will provide a field of view of at least one square degree with an excellent image quality and a good UV transmission. It will include an autoguider/autofocus unit as well as a tip/tilt image stabilizer (in order to make the best use of the excellent image quality of the CFHT site), to be installed in a new upper end with a new wide field corrector.

MegaCam, the MegaPrime camera itself, is a wide field imaging camera designed and built at CEA. It requires 36 to 40 2k x 4.5k three edge buttable EEV 42-90 CCDs with 13.5 micron pixels. Each exposure will produce more than 512 MB of data! The Mosaic will be read out in less than 30 seconds, which means that MegaPrime will produce approximately 30 GB of scientific data each night! In parallel with MegaPrime, the Terapix project ( is taking care of the data processing of the impressive amount of pixels produces by MegaCam.

2) Present status of the project

In mid 1998, the main items to be mentioned are as following:

Editor: Dr. Timothy M. C. Abbott,
Copyright © 1998, CFHT Corporation. All rights reserved.