Let’s begin by stating that the ideal base image format is a RAW file. We sincerely believe that the data straight of the camera’s sensor is the best way to store your image. In our experience, improvements in RAW processing software mean more information can be extracted from your digital camera files in time!
So why would you use or keep a jpeg or tiff file?
At present, RAW format allows only minimal editing, so immediately you need to move to a standard image format. If you intend to do serious editing involving layers, then keeping a Photoshop format file is a good idea, then you can always go back to the image and adjust your work. In recent years Tiff files can have layers, but these files can be very large, and it seems that the Photoshop format makes the layered file a little smaller.
Tiff files can also hold higher bit depths than jpegs, 16bit images are a natural choice if images need a lot of adjustment.
The beauty of Jpeg files is that they compress when closed. They take up less disk space. The compression, when set at “high quality” is virtually unnoticable, we prefer customers submit Jpeg files for most of our printing. Jpeg files have to be 8 bit and they are free from channels and layers which can accidentally be included in images which can cause print systems to produce odd looking images.
Here is the main problem with jpegs, the process of saving a jpeg, causes a pattern to be ‘etched’ in the image, the pattern is worse on low quality compression, on high quality compression, it is almost impossible to see. This pattern or jpeg ‘artifact’ will only show when an image is greatly interpolated, or up sized. So if we are making a big print from your jpeg file, we may ask for the tiff file, or perhaps the RAW file.
By ‘big print’ we mean where the print resolution is below 150ppi at print size. You can assess this by:
- opening your image in Photoshop
- go to the image menu
- choose image size
- turn off resample image
- enter the size print you want
- note the resolution, if it is below 150ppi, call us.
In conclusion, please send us jpeg files unless you need dramatic colour correction or really large prints. And keep an eye on improvements in RAW editing software, with each new version more can be done with your images, soon pixel level editing may be history!