Common Image File Types (What Are They & When to Use Them)

Common Image File Types

As a photographer and a user of both Lightroom and Photoshop, I see quite a range of photo file types - from our original RAW files, to TIFF, JPEG and PNG. 

If you are wondering about the characteristics of each image file type, their extensions and when you should use them, this post will help you understand the basics. 

Below is a list of the most common file types found in photo editing including the abbreviation, file name, and how they are used.

1. RAW - Camera RAW

RAW files are produced in your camera (often called Camera Raw) and are unprocessed.  A RAW file is considered lossless, which means it is not compressed in any way and gives you the maximum amount of information within the file.  RAW files do require conversion to be edited, and are not viewable within an internet browser (for example you cannot upload a RAW image file to Facebook).

2. DNG - Digital Negative

After importing your RAW files onto your computer, Lightroom will allow you to then export your image as a DNG file.  While still considered a "RAW" file format because they are lossless, DNG's are a lot smaller than RAW files.  Once converted from RAW to DNG, the file can be read with any type of software that supports the DNG format.

DNG is also the proprietary file format of Adobe.  When you shoot in RAW, your image file contains information that is unique to your camera's manufacturer.  Converting your RAW file to a DNG makes the file more universal, therefore more usable across Adobe software.

3. PSD - Photoshop Format

Both Lightroom and Photoshop support image formats with .psd file extension, which is extremely useful if you edit in both of these Adobe software programs.  The PSD format, in Photoshop, allows you to work with layers, but can also be manipulated in Lightroom (though Lightroom does not utilize layers).  You can still edit the PSD file in Lightroom and then bring back in to Photoshop with the layers intact.

4. JPEG - Joint Photographic Experts Group

JPEG files are a compressed, "lossy" file format that are great for sharing online or through email and text.  They do not contain as much information as RAW or DNG files, therefore they are not considered the best file format for editing, but they are extremely handy for quick viewing and sharing and for that reason are one of the most common file types. 

5. TIFF - Tagged Image File Format

TIFF files are slightly larger than JPEG files, can be either compressed or uncompressed, and are a standard file format among printers.  While most print labs will accept only JPEG's, some print labs will recommend sending TIFF's for printing. 

6. PNG - Portable Network Graphics

The PNG file format is often used by graphic designers, because the format lends itself to producing the most detail within solid colors.  Photographers often use this format for uploading their images to Facebook, Instagram and other social media platforms.  Since PNG's tend to run a bit larger than JPEG's, though, make sure that, when you upload to Facebook, your PNG is under 1 MB, otherwise you may run into some pixelation issues.

How to Choose the Image File Type to Use?

So, when should you use each particular file format?  Well, a lot of that is up to you and your personal preferences and/or needs.  I am not someone who swears by one method over the other in a given situation, but I do think it is helpful to know some basic guidelines.  Here is a general rule of thumb:

Use These File Types For Editing:

• RAW
• DNG
• PSD
• TIFF

Use These File Types For Sharing Online:

• JPEG
• PNG

Use These File Types For Printing:

• JPEG
• TIFF
• PSD
• PNG

Do you have any questions or comments about Image File Types?  Leave us a comment below - we would LOVE to hear from you!  And PLEASE SHARE this post using the social sharing buttons (we really appreciate it)!