One Degree Imager (ODI)

The WIYN One Degree Imager (ODI)

A rendering of the One Degree Imager mounted on the WIYN 3.5-meter Telescope at Kitt Peak National Observatory.

The WIYN One Degree Imager (ODI) is a state-of-the-art wide-field imaging instrument mounted at the f/6.3 Nasmyth port on the WIYN 3.5-meter Telescope at Kitt Peak National Observatory. With its 40x48-arcminute (0.67x0.75-degree) field of view, ODI can capture an area of the sky two and a half times the size of the full Moon in a single image while resolving objects as small as 0.3 arcseconds (0.000083 degrees) across. This makes it ideal for taking detailed images of large but faint astronomical objects. 

ODI utilizes both WIYN's wide field of view and excellent image quality. The image is broken down into individual pixels, each covering 0.11 arcseconds (0.000003056 degrees) of sky. The sharpness of images can be actively improved by correcting images for tip/tilt image motion. ODI is funded by the WIYN partners and the U.S. National Science Foundation.

Bubble Nebula (NGC 7635)

A wide-view image of the Bubble Nebula (NGC 7635), demonstrating the large field of view.

An advantage of the ODI camera is that it is not directly attached to the telescope tube. As the telescope swings across the night sky, the massive 1270-kilogram (2800-pound) camera is permanently and safely mounted at a fixed location at the Nasmyth focus. Here, the camera can accommodate very large special filters that each transmit a very narrow range of color, something that would be difficult for a camera mounted directly on the telescope. 

Science Highlights of ODI

Quick Facts

  • ODI can image an area of the sky two and a half times that of the full Moon
  • ODI can resolve objects as small as 0.3 arcseconds — about the equivalent of seeing a baseball at a distance of 50 kilometers (30 miles) 
  • Each image downloaded from ODI is two gigabytes in size, generating between one and four terabytes of data per night


One Degree Imager (ODI)

The technical information for astronomical observations is available at the NOIRLab Science webpage.


Kitt Peak National Observatory


WIYN 3.5-meter Telescope



Wavelength range

320–930 nanometers

Spatial resolution

0.11 arcseconds per pixel

Number of detectors

30 Orthogonal Transfer Array CCDs

Detector format

Each OTA CCD comprises 64 480x496 pixel cells

Detector total size 

About 480 million pixels

Spectral resolution


Field of view

40 x 48 arcminutes (0.67 x 0.75 degrees)


u’, g’, r’, i’, z’, NB422, NB695, NB746, H-alpha

Date of first light 

July 2015

Science goals

Projects with ODI include surveys of galaxies too distant for their shapes and structure to be discerned, studies of the motions of galaxies, and direct distance measures of stars much fainter than is possible with existing instruments.

Images taken with the instruments


Images of the instrument


Videos of the Instrument


Press releases with the instrument