Mike Chaney's Tech Corner

Technical Discussions => Articles => Topic started by: admin on May 27, 2009, 03:13:41 PM



Title: August 2008: Stop "Cooking" Your Photos: Shoot Raw!
Post by: admin on May 27, 2009, 03:13:41 PM

Stop "Cooking" Your Photos; Shoot Raw!


Background

In July 2006, I wrote a brief article about how shooting in raw capture mode could change your outlook on photography.  While the benefits of shooting in raw capture mode are as clear today as they were two years ago, still, a lot has changed in two years.  Have you changed, or are you still shooting in JPEG capture mode with your camera?   Let's take a look at raw shooting, how it can benefit you, and discover some of the tools used today to help you in your "raw workflow".

 

Raw versus JPEG

Many recent cameras offer the ability to shoot in raw capture mode as well as JPEG capture mode.  While JPEG capture modes are often labelled "Large", "Fine", or "Basic", the "Raw" menu selection gives you access to a shooting mode that is entirely different.  When shooting in raw capture mode, the raw data (basically the data straight from the sensor) is stored in a (usually proprietary format) file on your flash card.  While you can review your shots on the camera, you'll need to "develop" the raw data once you download the raw files from your flash card before you can view or print them using your computer.

So what's the benefit of shooting in raw capture mode?  In a word: quality!  When you shoot in JPEG capture mode, you're looking at a processed image.  Basically, your camera has taken the raw data and "cooked" it in order to create a JPEG image from that data.  If your white balance, exposure, and lighting are perfect, JPEG shooting might be OK.  Problems arise, however, when you need to rescue an underexposed or overexposed shot because the JPEG data has already been "truncated" to the exposure used by the camera.  Your JPEG has 256 steps or gradations for each color and in an underexposed shot, only the first 64 steps may be used.  When you brighten the photo, you see banding, noise, and other artifacts because you've truncated a 16.7 million color image down to about only 260,000 possible colors!

Unlike a JPEG, the raw data contains a much finer version of the data: one that has (usually) anywhere from 4096 steps to as many as 16,384 steps for each color.  Even with a 12 bit raw file that has 4096 steps or "shades" for each (red, green, and blue) color, instead of having only 64 steps to work with as with your JPEG, you now have over 1000 steps even on your underexposed image.  Now you can brighten the photo by adding exposure compensation without the ugly stepping patterns produced by the JPEG.

In addition to having more "granularity", raw photos also contain something called "headroom".  Headroom is an area of beyond-white steps that allow you to pull back exposure to recover blown highlights.  If you shoot a yellow flower only to find that a large portion of the flower is blown out (bright yellow with no detail), there's no way to recover the lost data with a JPEG.  If the same shot had been taken in raw capture mode, some if not all of the blown out highlights could be recovered because there's enough data in the raw file for it to capture steps (brightness values) beyond what would appear at maximum (255) in your JPEG's.

Simply put, shooting in JPEG capture mode is equivalent to being on a construction job, quickly measuring once, and cutting a board based on that one quick-and-dirty measurement.  After cutting, if you find out that you cut your board too short, there's no way to go back and make it longer.  The bottom line here is that JPEG files throw away data.  Don't cut your data based on the assumption that your camera (or you) will always meter and set up the scene properly!  Shoot in raw capture mode so you can make the most of your photos.  I've seen many photos that were destined for the recycle bin using the JPEG version but are easily rescued by using the raw photo.

 

Handling and developing your raw photos

The down side (if you can call it that) of shooting in raw capture mode is that you may not be able to just open them in your favorite photo printing tool and click the print button like you may have done with your JPEG's.  Two years ago, the process wasn't so simple.  You needed software to develop the raw photos first, and not all cameras came with such software, so you had to buy third party software costing from $100 to $200 just to be able to do anything with your raw photos.  To make matters worse, every manufacturer had their own proprietary format for the raw photos and even within one manufacturer, the raw format usually differed from model to model.  This made it difficult for any one software package to support all cameras, making you have to search to find a solution that would work with your particular camera.

Fast forward to August 2008 and things have changed considerably.  There are now open source solutions that cover almost every camera that can shoot in raw capture mode and while manufacturers still haven't made any headway into coming to an agreement on one international standard for raw photos, at least there are a wide variety of applications now that can handle almost any raw photos from any camera.

Even more interesting is the fact that some tools are now allowing you to treat raw photos like any other type of photo such as JPEG's.  The Studio Edition of my own Qimage software, for example, allows you to view, convert, print, and tweak raw photos just like any other supported image format while applying automatic exposure and noise reduction, thereby minimizing the amount of tweaking needed to get the best from your raw photos.  With more and more tools supporting raw photos in different ways, it's a lot easier to find the right tools to make raw shooting agree with your own preferred workflow.  Some people like to fiddle with each photo, trying different settings, while others just want to be able to get the best automatic rendition possible in order to minimize extra work.  Whichever boat you find yourself in, there are many raw tools to choose from.  Here's a quick list of some of the more popular "high end" third party solutions and their strengths.  Note that manufacturer solutions (that come with your camera or can be ordered separately) are not included.  Note also that the solutions below are, in my opinion, solutions that are acceptable tools to use to view, publish, or print final versions of your raw photos.  There are many more tools that "support" raw formats that I didn't list because while you can get an "image" from them, they lack essentials for final output like color management or proper color transforms to allow for accurate color.  So if you use a particular raw tool that is not listed, it's most likely because I didn't consider that tool a major player in the field of quality raw tools.

Raw Tool Price range* Strength(s)
Adobe Camera Raw Free
(must have PhotoShop)
Integrates w/PhotoShop
Lots of aftermarket "add-ons"
Adobe Lightroom $299 Emphasis on image
management and cataloging
Bibble $70 - $130 Excellent quality
Unprecedented control
Capture One 4 $129 Excellent color
Profiles for many cameras
Qimage Studio $90 Minimizes need to tweak each
photo.  Color accuracy.
Silkypix Free - $149 Emphasis on color accuracy
and noise control

* as of July 2008

 

Summary

Shooting in raw capture mode can be a major advantage if you are interested in squeezing the most quality from your photos.  With some of the latest raw-capable tools on the market, shooting raw and being able to find an acceptable workflow for actually using the raw files has become much easier in the last year or so.  Not convinced?  Try shooting some photos in raw format before you make up your mind.  If your camera offers a JPEG+Raw shooting mode where you can actually capture both, try that and compare what you can get from the raw versus the JPEG images.  I did that at first, and now I've dumped JPEG shooting altogether as I can always get better quality from the raw photos and the added JPEG version just takes up space on my flash cards!

At the end of the day, taking the time to learn which raw tool(s) are best for you and working out your own personal raw workflow will pay dividends and can help you get better photos than ever.  So if you looked into raw shooting before and it seemed that the extra effort wasn't worth it, it may be time to give it another try.

 

Mike Chaney