What a NEF contains

As a raw nef file is a dump of camera information and not an actual image, it is very different how the nef file is displayed in different applications.

Let's for example assume that you take a black-and-white picture with your Nikon. FastStone, IrfanView and xnview all display the image as black-and-white. However, the gimp, Picasa, Aperture 2.1 and Mac OS X' Preview ignore the tag that says that the image should be black-and-white, so they display the image in colour.

Nikon's Capture NX keeps the camera information, so it appears black-and-white, but one can also go back to the original colours.

1. Go to Base Adjustments > Camera Adjustments > Picture Control.
2. In the dialogue that comes up, change "Non-Picture Control" to "Picture control".
3. Change the settings to what you prefer.

Sometimes it is not obvious to see what changes have taken place in the camera. I for example had a picture where the White Balance was far off. There is no indication in the adjustment panel of Capture NX, that the White Balance had an unusual setting in the camera, so I had to look around for some time, before I found where it was.

White balance is, by the way, one camera setting that Aperture takes into account.

This may appear confusing for a simple reason: it is confusing. Not only are the names for the features sometimes confusing, but the concept itself is confusing.

There are a couple of metaphors one can use.

Think of the raw data from the camera as a Word document. If you switch on Track Changes in Word (or Record Changes in OpenOffice) you can make as much modifications you want. Add text. Remove formatting. Change pictures. You can always select Reject All Changes to go back to the original. You can also reject some changes and keep others. In the same way, you can always go back to the original camera raw data in a nef file, no matter how many changes you have made. You can also revert some changes, even if they were made in the camera, but keep others.

A more real life metaphor is a dinner table. Let's say you change the tablecloth every day. You use different kinds of china and put different dishes on the table every day, so it looks very different from one day to the next. No matter what things you add, you can always remove them at the end of the day. What you are left with is the original naked wooden table. In the same way, you can add effects to a nef file - sharpening, blur, white balance, noise reduction. But at the end of the day, you can remove them all, and what you are left with is the original camera raw data.

Many applications open nef files, but they almost never save to nef format. If you make a modification, you will have to save the image as tiff, jpeg or some other more mainstream format.

Capture NX is an exception, as it saves the modifications in the nef file itself. However, it does not touch the actual raw data in the nef file.

Some of the data that can be stored in a nef without touching the actual raw data.