In astronomy, a deep field is a compiled image of a portion of space using very long time exposures to look at distant faint objects.

The aim of the Hubble Ultra Deep Field view (HXDF) was to study galaxy evolution and active galactic nucleus within one billion years of the Big Bang. The HXDF focused on an area in space in the constellation FORNAX, and used about 50 days of exposure time over ten years to compile its image.

Using two cameras: full color imaging from the advanced camera for surveys, and the wide field camera 3, which included infrared imaging, the HXDF captured about 5500 galaxies.

NASA scientists estimate that the universe is about 13.7 billion years old, and the HXDF was able to span back to about 13.2 billion years. In 2022, NASA began releasing deep space images from the James Webb telescope also going back 13 billion years in another part of the universe.