Laura Balsam
Classes Outlines

Many cameras can save photos in one or more file formats.

You almost always have to go into the camera's menus in order to change formats, so this is not something you do constantly as you shoot.

The format you choose can have a huge impact on your file sizes and image quality.

The general trade-off is that better quality requires larger file sizes.

The RAW file format is not available on most low end cameras. It gives you the most flexibility to enhance your images, but it also requires you to take extra steps before a photo is usable.

File Formats Cameras Create

Your camera can save photos in one or more of these formats

If your camera will only produce one type of files it will be JPG.

Check you camera's manual for the available options
and how to change them.

JPG
The most common format
Wikipedia Page

JPG and JPEG are often used interchangeably.

JPG is the file name extension used for files created with JPEG compression.

The most common format, has been around a long time. Many cameras will only save pictures as JPGs.

JPG and GIF were the only image two formats commonly used on web pages for many years. JPEG file compression became very popular because the files it created were small.

JPEG compression was developed around 1991. At the time computers were slower, had less memory and smaller hard drives. Photographs were huge by current standards and many computers struggled or could not handle the large files.

Today JPGs are the most common files on the web and almost all e-mailed pictures are JPGs.

The problem is that when you open and re-save a JPG, the file is re-compressed and additional detail is lost and more JPG artifacts are created (they look like noise).

TIFF
Wikipedia Page

Standards for
Tagged Image File Format

The file extension is TIF

Until the RAW format became popular. TIFF files were standard for exchanging high quality images.

The file sizes are much bigger than JPGs and a little bigger than RAW files.

TIFFs are often used in desktop publishing.

RAW
Sensor Data
Wikipedia Page

The file extension will vary form one camera manufacturer to another.

This is your data as it comes off the camera's sensor. It and DNG are the only formats not manipulated by the camera's onboard software.

Some software cannot handle RAW files. New sensors are being introduced all the time and new RAW file formats are added.

Picasa, Elements, Lightroom and Photoshop are periodically updated to support the latest RAW formats.

When a camera processes the data from it's sensor in order to create a JPEG or TIF image, it is the equivalent of making a print form a negative. Just as in the darkroom you can make changes to make a better photograph, in the "digital darkroom" you can control the conversion of the RAW data into a usable image format and get a better image.

If you are using Lightroom or Photoshop there is a definite advantage to using RAW files. With most images you can create a vastly improved image.The most important reason being that your can often recover blown highlight detail. This means washed out skies can often be greatly improved.

If you are using Picasa the software that came with the camera will allow you to control the RAW to conversion processes. If you use Lightroom or Photoshop you will probably not need to install the manufacturer's software.

DMG
Adobe's universal
RAW format
Wikipedia Page

The file extension is DNG.

Most RAW files can be converted to DNG with no loss of data using free software from Adobe.
Windows Version
Mac Version

The same as RAW, except that the data is stored in a "standard" developed and owned by Adobe.

DNG is being offered as an alternative to the ever increasing number of RAW formats created by the various camera manufacturers.

The manufacturer's want you to use their proprietary software. Photographers are worried that a proliferation of RAW formats might eventually leave them with orphaned files. Files they would not be able to opened.

DNG would theoretically provide all the information of the manufacturer's RAW format with the added benefit of being standardized and maintained by Adobe. Theoretically DNG file would never be orphaned.

PSD
Photoshop Files

This is Photoshop;s "native" format. It stores all the layers and effects that Photoshop can create.

If you are working on a photo in Photoshop, Lightroom or Photoshop Elements saving it as a PSD retains it's image quality and gives you the maximum flexibility to make changes later.

PSD files must often be converted to other formats, such as JPG or TIFF, in order to be used by other programs.

GIF
Web only
Wikipedia Page

Transparency
Good for logos.

An extremely old file format. Hardly any cameras can save in GIF format.

It is one of the most common image formats for web pages. For a long time it was the only format that supported transparency. So if you wanted to use non-rectangular image or logo it was usually done as a gif.

GIFs are limited to a maximum of 256 colors, so they are not good for continuous tone images. They are commonly used for images that have very few colors because the file sizes can be very small.

Adobe created the PDF format as a way to make documents and graphics portable from one machine to another and one operating system to another.

In the bad old days we used fonts embedded in printer firmware when printing documents. This caused major problems since the formatting of a document was dependant on the printer used to print it.

There was also trouble sending documents between Macs and PCs.

The PDF format was created to address this issue, it became a standard in desktop publishing. PDF's also became a standard way to exchange images regardless of what program or operating system was used to create it.

PDF's can contain a mixture of pixel based and vector elements.

There are many other file formats used in graphics,
these are the most common and important ones.