Deep Lens Survey

Please see the image access page for descriptions of these images. Coordinates of the fields are available on the survey description page.

The uncompressed images and weight images are 400 MB each. The n images are losslessly compressed with fpack from a raw size of 400 MB down to about 24 MB each. The compressed images and weight images are lossy-compressed with fpack to 72-80 MB each. They look amazingly similar to the original images; the bits which have been suppressed are noise bits.

If you are not familiar with fpack, do not be afraid. The decompression code is now included in the cfitsio library and in ds9, so decompression will probably be done automatically and on-the-fly as you use the data. If you want to keep an unpacked file on your end, use the funpack command. The loss of quality is minimal. We use fpack's default q=4, which results in only about 0.26% loss of precision. See the fpack home page for more details on the algorithm and links to the fpack paper.

The zeropoints of these images are:

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• Images

  • Navigator
  • Gallery: a few remarkable images
  • Cosmic wallpaper
  • Layperson's guide to images and science

• Data Release

  • Overview
  • Catalog access
  • Image access
  • Transients
  • Overlapping data

• News

  • New DLS website launched
  • Photometric redshift innovations
  • Cosmic shear results
  • All news...