PEF File Format (.pef)

A PEF file holds unprocessed sensor data captured by a Pentax digital SLR, stored in a TIFF-based container that Pentax has used as its native raw format since the *ist D in 2003.

.pefImage Files

PEF at a glance#

Full name	Pentax Electronic File
File extension	.pef
Category	Image Files
Developer	Pentax
First released	2003
MIME types	image/x-pentax-pef
Compression	Lossless
FileFlip support	FileFlip reads this format but does not write it

What a .pef file can hold#

These are the things a PEF file either supports or does not, and they are what decides whether a conversion keeps everything or quietly drops something.

Lossless compression	Yes
Embedded metadata	Yes
Colour profiles	Yes

Strengths and limitations of PEF#

What PEF does well

Lossless compression keeps file sizes down without discarding any sensor data
Full sensor readout gives far more exposure and white balance latitude than an in-camera JPEG
Ricoh's own Digital Camera Utility still reads PEF files back to the *ist D, so older Pentax raw archives stay usable with official software

Where PEF falls short

Pentax has never published the PEF specification, so support outside Adobe and Pentax's own tools depends on reverse-engineered decoders
Files are much larger than a JPEG from the same camera and need dedicated raw software to view
Pentax's camera menu can shoot DNG instead of PEF, so raw files from the same camera line aren't always the same format

Shoot PEF, Pentax's default raw setting, to keep full sensor data with Pentax's own lossless compression, and switch the camera to DNG only if a specific workflow needs Adobe's open raw container instead.

Convert PEF once editing is done and the image needs to open somewhere that doesn't read camera raw, such as a web upload, a shared album, or a printer.

How to open a .pef file#

A .pef file opens in the programs below, grouped by the platform you are on. If you would rather not install anything, FileFlip converts PEF into a format your machine already opens, and it does it in the browser tab rather than on a server.

Platform	Programs that open it
Windows	Adobe Photoshop, Adobe Lightroom Classic, Pentax Digital Camera Utility 5, RawTherapee, darktable
macOS	Adobe Lightroom Classic, Adobe Photoshop, Preview, Photos, Pentax Digital Camera Utility 5, RawTherapee
Linux	RawTherapee, darktable, digiKam
Web	FileFlip

PEF questions people ask#

What camera creates PEF files?

PEF files come from Pentax K-mount digital SLRs and the Pentax Q series shooting in raw mode, starting with the *ist D in 2003. It's Pentax's own raw format, distinct from the DNG option the same cameras can also write.

Should I shoot PEF or DNG on a Pentax camera?

Pentax cameras let you choose PEF or DNG as the raw format in the camera menu. PEF is Pentax's native format with the camera's own lossless compression, while DNG is Adobe's open raw container, useful mainly if a workflow specifically expects DNG.

What software opens PEF files?

Adobe Camera Raw, Lightroom Classic and Photoshop all open PEF files, as do Pentax's own Digital Camera Utility and open-source raw processors like RawTherapee and darktable. Most general image viewers cannot open a PEF without one of these.

Does converting PEF to JPG lose image quality?

Converting a PEF file to JPG applies the raw processing (demosaicing, white balance, tone curve) and then compresses the result, so some of the original sensor data is discarded in the process. The source PEF file is untouched by the conversion.

Converting PEF files#

FileFlip does not write .pef files, so nothing on the site converts into this format. It works as a source only.

Every conversion runs inside your browser. The file is read from your disk, the work happens on your own machine, and nothing is uploaded. How FileFlip works names the engine behind each family and how to verify that for yourself.