Search This Blog

What is RAW Format Photography

Posted

Note: This post was originally published on January 15, 2017, as the first part of a three-part series on RAW format mobile photography. Some details have changed considerably since then — notably, the open-source DNG format has indeed become widely adopted as I'd hoped. I've left the original text in place as a record of where things stood at the time.

A photograph of the Chinese Gardens at the Huntington Library in San Marino, California, developed from a DNG RAW file taken with a Google Pixel XL smartphone.
A photograph of the Chinese Gardens at the Huntington Library in San Marino, California, developed from a DNG file taken with a Google Pixel XL smartphone.

I find the best way to understand RAW format photography is to liken it to its equivalent in film photography. You can think of a RAW format file as the equivalent of the negative in the world of film photography.

Film photographers expose their photograph onto a light-sensitive filmstrip or plate and then develop that into a negative. Using various processes and adjustments, the negative can then be printed multiple times and in different ways, resulting in a variety of photographic prints.

In the realm of digital photography, the RAW file is the equivalent of the image stored on the film. Just like with a film negative, from the one RAW file, many different images can be rendered in the "post-processing" of the "digital darkroom". No matter how many different treatments the original negative (RAW file) is given, the RAW file is always available intact in its original state, ready for you to start from scratch again.

The other option in the modern digital photography world is to take your photos in jpeg format. The jpeg file can be compared to a developed print in the world of film photography. When you take a photo in jpeg format, your camera makes its own judgements about how the final print should look using what's known as an "algorithm" executed by the software in your camera or mobile phone. Essentially the software acts as developer and post-processor and comes up with a "print" for you. The "negative" of the original image with all its "raw" information is not retained.

The jpeg file is also compressed, meaning after the algorithm is executed and the "print" file is finalized, some of the data is discarded in the interests of creating a smaller file. This technology was developed in the early days of computing and the internet, when smaller files were preferred because of the cost of storage and the narrow bandwidth of the internet in the days of "dial-up modems".

The Advantages of RAW Over JPEG

  • The file is not compressed; none of the information necessary to create the image from the RAW file is discarded. In fact, the RAW file is not really an image at all, but a file containing all of the information necessary to generate an image.
  • The metadata of the RAW file can be adjusted in "the digital darkroom" in a non-destructive manner, which means that at any time, you can go back and "reset" any adjustments you have made and return to the original RAW file.
  • The final judgements of how the image and print file should be rendered are left to the photographer, and not to a software algorithm.

DNG: A Common RAW Format

Each camera maker has their own proprietary RAW file format. For example, Canon's RAW format files use CRW as the file extension. Nikon uses NEF. To be able to read the file and render it as an image you need to use software that has a converter or plug-in that can read and render the RAW file. The most widely known examples of such software are Adobe Photoshop and Adobe Lightroom.

However, the trend is now to use a common RAW file format that has long been advocated by Adobe, known as the "digital negative" RAW file format. Such files use DNG as their file extension. This is an "open source" format. Recently, Google adopted DNG as its standard for RAW format files for devices using the Android operating system — a move that should give considerable impetus to the adoption of this common format by all camera makers.

Hopefully I have been able to answer your question as to what RAW format photography is all about. In my next post I will tell you how you can take DNG photos using an Android phone, and also how to process the file with some apps for Android phones. See you then!

— John Corney

Labels:

Comments

Post a Comment
Subscribe to: Post Comments (Atom)

Most popular posts in the last 30 days

A Dose of Capybara Cuteness to Brighten Your Day

Posted
Sometimes the internet delivers a piece of pure, unexpected joy — and today, that joy comes in the form of a capybara ready for its ballet debut. Tutu Cute Capybara Known as the chillest animal on the planet, the capybara is famous for its serene demeanor and its uncanny ability to befriend just about every other creature. But what happens when this icon of calm decides to trade a quiet soak for a spirited plié ? You get this: a masterpiece of whimsy. This tutu-wearing trailblazer is a perfect reminder to embrace the silly, find your own rhythm, and dance like nobody's watching — even if you're a giant rodent built more for lounging than for leaping. So the next time you feel like you don't quite fit the mold, just remember this capybara. Put on your own proverbial pink tutu, whatever that may be, and let your happy spirit shine. Perhaps there's a little princess in yo...
Image

Samoan Youth

Posted
This young man was preparing with his friends for his moment of fame on the stage at the Samoan Village at the Polynesian dance festival called Pasifika in Auckland in March this year. Samoan Youth Canon EOS 20D 1/30sec at f/20 ISO 200 Canon 70-300mm lens at 300mm More photographs from the same Pasifika Festival day can be found in my new post, Faces of Pasifika 2007 — A Day at Auckland's Pacific Festival .
Image

The Farmers Queen Street Santa — An Auckland Christmas Icon

Posted
The Queen Street Santa is one of those pieces of Auckland Christmas iconography that's hard to explain to anyone who didn't grow up seeing it. Standing 18 metres tall, the statue's history is more layered than most people realise: it started life on the original Farmers building at the corner of Hobson and Wyndham Streets in 1960, moved briefly to the Manukau City Shopping Centre in the early '90s, then settled onto the Whitcoulls building on Queen Street, where it stood through the 1990s and 2000s — which is where I photographed it in January 2010, in the photo below. Farmers itself later moved back into that same Queen Street building in 2020, and the giant Santa went back up that Christmas along with them. As far as I can tell, though, it hasn't reappeared since — 2020 seems to be its last confirmed outing, which fits with what a lot of older Kiwis have told me: they remember it fondly, but suspect it's gone for good. The Farmers Santa — Queen St...
Image

A Grunge Botanical Collection — Five Painterly Garden Pieces

Posted
Over the past few weeks I've been building out a small collection of botanical pieces using photos taken in my garden here in Irvine, California, (and in one case out on a hiking trail here in SoCal), and using AI assistance to give each one a grunge, painterly treatment — dark, richly textured backgrounds with warm gold light breaking through, turning garden snapshots and trailside finds into something closer to old varnished still-life paintings than straight photography. Here's the full set so far. Epiphyllum oxypetalum — Queen of the Night, Painterly Botanical Art A night-blooming cactus that flowers just once or twice a year, for a single night — three blooms at different stages caught in one frame from a night it happened in my garden. Kangaroo Paw — Painterly Grunge Botanical Art Australia's velvety-flowered native, grown in my own garden, its stems reaching in different directions the way it actually grows rather than posed into symmetry. ...
Image

Long Beach Gay Pride 2008 Pictures

Posted
Sr. Lupita, a Sister of Perpetual Indulgence, Long Beach Pride Parade 2008 © John Corney 2008 June is LGBT Pride month in America, with Southern California's celebrations kicking off at the Long Beach Pride Festival toward the end of May. These events are a gift for photography — color, spectacle, and every flavor of self-expression a crowd can muster, without much need to go looking for it. Long Beach delivers on all three: pageant contestants working the crowd in their sashes, a procession of the always-theatrical "Sisters of Perpetual Indulgence" — among them, as I've since learned, Sr. Lupita, pictured above — a cyclist pausing mid-route, and, because no Pride parade is complete without one, the usual contingent of Christian protestors along the sidelines. Sr. Lupita turns out to be something of a recurring face in my archive; I've photographed her before, in a post of her own . Below is a selection from that day, reflecting the diversity of ga...
Image