JPEG
JPEG stands for Joint Photographic Experts Group and is named after the committee that created it in 1986.
It is not as sharp out of the camera as TIFF or RAW modes, and every time the JPEG is manipulated more than once or twice, it will eventually become unusable. Every time the JPEG image is modified and resaved, it will lose more data.
Once compressed in JPEG format an image cannot be uncompressed (you cannot regain the original quality). This is why the original photo (your digital negative) should be taken with as little compression as possible.
When to use:
- emailing
- posting to the web
When NOT to use:
- Printing (while we can use jpeg files for printing we would prefer a larger file in the form of a tiff or PSD, if the jpeg is compressed to heavily we do not recommend printing with it at all)
TIFF
TIFF stands for Tag Image File Format.
Tifs have a high image quality and is supported by many image-manipulation programs such as PhotoShop, Pagemaker, QuarkXPress, Adobe InDesign, Paint Shop Pro, etc. You can have layers in photoshop when you safe with a tif and it can be modified and resaved, with the images being used an endless number of times without throwing away any image data.
When to use:
- Printing
- Editing in programs
- Saving master files
- Publishing
When NOT to use:
- Emailing
- Posting to web
RAW
The RAW mode is a picture format where the camera has made absolutely no changes; the files are not yet processed or ready to use with an editor, etc.
Its advantages are that a huge amount of control over the final look of the image is yours. Additionally, all original details stays in the image for any and all future processing needs.
The general rule is to shoot your images with the highest setting that your camera will allow (largest image size in terms of pixels, lowest compression – usually large/superfine).
When to use:
- While shooting
When NOT to use:
- Emailing
- Posting to web