Skip to Main Content U.S. Department of Energy

Technical Information About PictureThis Files

The two most important technical details for dealing with photographs are the file type and the resolution.

File Type

While there are dozens of image file types, the most common are TIFFs or JPEGs. PictureThis can provide you with either a TIFF or JPEG file.

TIFF files (TIFF stands for Tagged Image File Format) do not depend on computer-specific software (that is, they can be used on Macs or PCs). TIFF files, which can be quite large, are one of the best file types to use for printed images and can be imported into most word processing, page layout, and drawing programs.

To obtain TIFF files from PictureThis, follow the instructions on the screen below a selected photograph.

JPEG files are especially good for use on the Web or in presentations. These files are compressed, making them much smaller than TIFFs.

To obtain a JPEG image from PictureThis: On a PC, right mouse click on the image and choose "Save Image As...." On a Mac, option+click on the image and choose "Save Image As...".


Resolution is the number of pixels or dots per unit of measure (for example, dots per inch or dpi).

If you want high-quality printed photos (for offset printing, etc.) use at least 240 dpi.

If you want clear images from a laser printer, use at least 150 dpi.

Images to be used on the Web should be 72 dpi.

Most images on PictureThis are 300 dpi, but can be reduced in resolution and/or size using a drawing or image editing program such as Adobe's PhotoShop (trademark) and Jasc Software's Paint Shop Pro (trademark).