Photoshop Elements /

RAW File Processing - An Introduction

Each camera manufacturer has their own proprietary raw file format.

Adobe's RAW file format is an open standard.

Here are the file extension names for Nikon, Canon, and Adobe.

Nikon	.nef
Canon	.crw
Adobe	.dng

You need software that can open your particular type of raw file.

You can use:

• Your camera manufacturer's software, such as Nikon Capture or Canon's Digital Photo Professional.

• Use software made by others.

• Use the Adobe RAW converter included with Photoshop CS2 and Photoshop Elements.

Notes

The screenshots of menus below are from Nikon Capture Editor 4.

The software you use will have similar operations and menus.

The metadata for your RAW file contains an EXIF (Exchangeable Image File) file, or similar file, in which settings for many of the operations below are specified.

However, these settings haven't been applied to the RAW file permanently.

In some cases, such as white balance, they may have been applied, but can be overridden.

Most often, these settings are not applied.

#1: Color Interpolation

Color interpolation, or demosaicing, is done automatically when you open a RAW file.

A complex interpolation algorithm determines the color of each pixel.

Most chips (the Fovean chip is the exception) are B&W chips, so to speak.

Each photosite has a red, green, or blue filter.

The filters are arranged as a Bayer Matrix (or Bayer Filter Array) across the sensor:

There are twice as many green filters.

This is because we see more green than red or blue.

So, while there are colored filters, no actual color is recorded.

Instead, the interpolation algorithm compares the brightness levels of adjacent photosites, and determines the color.

You do the following steps, as needed.

#2: Resize, Etc.

You can resize, change the resolution, and crop the photograph.

#3: Exposure Compensation

If you're exposure needs tweaking, you can adjust it within a range of two stops, or EV, plus or minus.

If you shift the exposure by more than .5, the white balance may change.

So, use exposure compensation before setting the white balance.

#4: White Balance

If the white balance you selected before you pressed the shutter release needs fine-tuning, you can do so easily.

#5: Tone Curves

This is one of the most necessary and useful operations.

You can change the contrast of your photograph using a automated operation, often called tone compensation, or you can adjust the curve yourself.

Read the Tone Curves.

#6: Color Saturation

As described above, you can adjust the white balance.

You can also adjust the color saturation.

Saturation is how much gray is mixed with a color.

A saturated red, for example, is vivid.

An unsaturated red, pink, is pastel.

The Nikon Capture 4 software has a Color Booster operation for decreasing saturation in photographs of people, and increasing it for landscapes and the like.

You can also adjust the color saturation in the Advanced RAW menu.

#7: Color Balance

You can use the color balance menu to adjust the brightness, contrast, and each color.

Unlike the tone curves menu, where you can adjust the shadows, midtones, or the highlights, the color balance menu operations are global.

Changes are made to the shadows, midtones, and highlights, equally.

#8: Other Operations

Your software will have a noise reduction operation.

If you used a low ISO setting, with short shutter speeds, there may be little need for noise reduction.

Your software may also have operations to correct lens distortion, the vignetting of wide-angle lenses, and so forth.

#9: Sharpening

Digital photographs need sharpening.

The sharpening step should always be the last step.

If you're going to edit the photograph further, wait to do sharpening.

You can use the unsharp mask filter in Photoshop Elements when you're finished editing.

Read Sharpening.

Batch Processing

The software you're using may process many files at the same time—batch processing.

RAW Converters

As mentioned, the Adobe RAW Converter is included in Photoshop CS2, and there's a RAW converter included in Photoshop Elements 4.0.

Adobe Camera RAW Included in Photoshop CS2 & Photoshop Elements

Bibble 4.0 Raw workflow software

Microsoft RAW Image Viewer for Windows XP Viewing only

RawShooter | essentials 2006 Free

rawformat Blog about RAW file formats