As photographers, we would normally take photographs in two basic file formats; ‘Raw’ and on occasions, ‘Jpeg’. In the post-production process we might use software including Lightroom, Adobe Camera Raw, Photoshop or Apple’s Aperture to ensure the best end photographic results.

Eventually, you have the perfect image and it’s now time to save your file. So which file format should you save it in? PSD, TIF, JPG, GIF, PNG, DNG? This decision can be a bit confusing!

Taking a standard Raw image of 11.15mb and without any adjustments, I saved it in various file formats, and here are the results:

• Original file = 11.15mb.
• JPEG version = 1.3mb.
• PSD version = 36.3mb.
• TIF version = 32mb.
• PNG version = 10.6mb
• DNG version = 10.2mb.

You can tell from the above list that the only difference is file size. So which one should I use to save my image? Well the answer is, it depends.

PSD – (Photoshop Document): Use this when you have multiple layers, masks, blending modes or many adjustments. These types of files are large but the benefit is that you can always re-open and modify your image at a later date.

But remember, these files are not suitable for web use – they’re photoshop production files designed so that you can go back to them at a later date to make changes, and then they are eventually saved as a different file-format according to their ‘end-usage’.

TIF – (Tagged Image File Format): This file type is of the highest possible quality and is excellent for all kinds of print media. This specialist format also keeps all the layers but this results in extremely large files size. If you want to keep files of the best quality then use this format, but if space is an issue, a JPEG may be a better alternative:

JPEG – (Joint Photographic Experts Group): This is the most common type of saved file. A JPEG can be saved in various qualities and file sizes and this flexibility can make this a suitable option for web-based imagery.

An example of its usage could be when using the best quality file format isn’t essential. You could use a lower-quality JPEG when your visitors have a lower speed connection and therefore a high quality (larger file) would take too long to load. An alternative would be for use on a mobile website – any occasion where the highest quality isn’t essential.

Of course, a JPEG is also suitable for print, but the file is compressed so it loses information; it is a flattened image, ie it has no layers.

PNG – (Portable Network Graphics): Ideal for web and graphics. This format boasts a smaller file size and results are excellent – there is no loss of quality, and is therefore generally used by web designers and developers in graphical production.

For photographs, JPEG’s will generally prove to be the better option, but  NG is deal if you need to maintain a transparency, or if you wish to share files on the web.

DNG – (Digital Negative): This is becoming the new standard for saving images, but why? For years camera manufacturers have all used their own Raw file format. Nikon’s file extension is .NEF, Canon’s is .CRW and there’s many more for each respective manufacturer, such as .DCS, .PERF, .RW3, .MEF and so on.

DNG is an ‘Open Standard’ created by Adobe, and they are keen for it to become the standard file format for the future. They have promised it will never be licensed and remain free to all.

In time, this standard will be adopted by all camera manufactures in the future and make life ‘a little simpler’.

I hope this blog has been useful to all readers.