Why convert FIT to TIFF?
Astrophotographers export FITS to 16-bit TIFF to bring images into standard photo editors such as Photoshop or GIMP that do not read FITS natively. A 16-bit TIFF retains the tonal depth needed for stretching, color balancing, and noise reduction without discarding the dynamic range the raw FITS captures - an 8-bit export throws away roughly half that information.
How to convert FIT to TIFF
NASA FITS Liberator FREE
Open the .fit file, choose a scaling function (Linear, Log, or Square Root) and adjust the black/white point sliders, then use File > Export as TIFF and select 16-bit per channel before saving.
SAOImageDS9 FREE
Open the .fit, set the display stretch in the Scale menu, then go to File > Save Image > TIFF to export the current view.
About these formats
.FIT
Flexible Image Transport System (FITS) image
A .fit file is a FITS (Flexible Image Transport System) astronomy image - the standard scientific data format used by telescopes, astrophotography cameras, and research archives since 1981.…
Open .FIT details →
.TIFF
Tagged Image File Format
A TIFF file is a Tagged Image File Format image - the standard for scanned documents, faxes, and archival photos. It opens without extra software on Windows (Photos app) and macOS…
Open .TIFF details →Quality & what to watch
- Always export as 16-bit TIFF - an 8-bit export discards roughly half the tonal information captured in the FITS data.
- A stretch must be applied before export; if skipped, the TIFF will appear black or overexposed because the raw pixel values lie far outside the normal display range.
- FITS header metadata (telescope, exposure, coordinates) is not carried into the TIFF; keep the original
.fitif that information is needed.
