RAW files Explained

Now I'm not going to get into a self-indulgent historical ramble about the 'good old days' of film because I never really liked it anyway, but going back to the days when people developed their own films, took the resulting negatives into their red floodlit darkrooms and produced their own enlargements, there was a surprisingly high level of control. You could do loads, but it took hours to do and years to learn.

Then digital, producing glossy jpegs that flattered the photographer that could also be edited in Adobe Photoshop. But little know fact that every time you click the shutter and a Jpeg is produced an awful lot of information is being discarded straight away by the clever little man that made your camera. This image shown here of the rose is the JPEG as shot. Not too bad I know but I can't be certain that those colours are realistic or actually what I want.To me I dont remember the rose being quite so orangey and I'm really not so sure about the blueish background any more (that I did actually shoot it against.

Worse still is every time you edit and save a jpeg in editing software even more information (and quality) is being thrown away. Compounded with the fact that cameras invariably have made some A.I. based decision about your photograph, what you're left with is starting to become not what you shot.

So the flexibility had gone when it needn't have. Every time you click the shutter the sensor gets some digital information and its simpler to think of this information as the RAW file (it isn't but don't worry about it). Literally the 1's and0's that come off the sensor. So RAW files carry a great deal more information than JPEGs, in fact its this information that the camera looks at and trims down into a JPEG which as we saw in the previous section isnt so bad, but the ORIGINAL UNTREATED RAW FILE shown here, looks horrible, dull and generally uninspiring. That's because no correction work has taken place yet.

All of the light information is preserved meaning that you can adjust colour temperature after you've shot the image and what's more because of the increased bandwidth you can work miracles with other types of corrections such from vignetting, burnt out highlights, introducing black, chromatic abberation and split toning etc... in fact the list of editing opportunities is more than a little extensive.

Here's the golden egg. RAW file editors do NOT overwrite data. They simply record the changes as additional information (either within the file or as a 'sidecar' file with the same name and with the .xmp extension). Pretty much like for example 'increase contrast by 10'. And if you change your mind, just reduce it by 10 later on. Total and perfect non-destructive editing.

What's more this information can be copied and duplicated onto other images from the same shoot. The hours that this saves are worth the cost of Adobe Photoshop alone.

This has changed a great many things because Photoshop is now used for creative purposes only, with Adobe Camera RAW being used for corrections prior to loading into photoshop.

So you're probably thinking 'oh no... all this extra work.... I dont have the time... i dont understand... ahhhh" . Not a problem. because here's the golden egg. RAW file editors do NOT overwrite data. They simply record the changes as additional information (either within the file or as a 'sidecar' file with the same name and with the .xmp extension). Pretty much like for example 'increase contrast by 10'. And if you change your mind, just reduce it by 10 later on. Total and perfect non-destructive editing.

What's more this information can be copied and duplicated onto other images from the same shoot. The hours that this saves are worth the cost of Adobe Photoshop alone. The original raw file for this different rose image here (I thought you might be getting bored with that one) is shown on the left the corrected ras file image is shown ont he right...... This update too LITERALLY 2 SECONDS.

This has changed a great many things because Photoshop is now used for creative purposes only, with Adobe Camera RAW being used for corrections prior to loading into photoshop.

It stands to reason that with hundreds of cameras with hundreds of sensor designs that each sensor would produce different raw files. And they do. The last I heard there were about 380 different types (correct as of Nov 09).

This makes it VERY difficult for the makers of editing software to ensure that their software can read all these types of files, the range of which is growing all the time.

When a new camera came on the market you would have to download an update for your software called a CODEC. and this was dependent upon whether your version of the software could use this new codec.

A standard RAW file format was needed.

With all these RAW files bursting onto the market not only were software manufacturers starting to suffer on a never ending mouse wheel of compatibility issues, but as cameras became older and, dare I say it, obsolete their RAW file became unsupported.

A standard was needed. Not an easy task as this standard had to be future proof as well. But Adobe invested very heavily in a new technology called DNG which stands for Digital NeGative.

The accepted wisdom is you convert your RAW files (canon use CR2, Nikon use NEF etc) into the DNG standard, meaning that regardless of what happens in the future with software, you can always edit your RAW file and convert it to an excellent image years later as if you had just shot it. Even years later.

Just to finish this brief introduction to raw files off, the net result of this technology is you have more control after shooting than ever before, it is future proof, you have full non destructive and recovery editing.

Now there is no excuse for trying to correct badly taken photographs because of all these options. But in low light, in mixed light sources and with quality improving all the time of higher ISO images, the level of copntrol and flexibility is the dawning of a new era.

My advice, start using RAW files as of yesterday.