Digital Photography - Digital Imaging - the RAW option

Iain Laskey gives an overview of the the RAW format used by many digital cameras.

Most consumer grade digital cameras have until recently only saved their images in JPG format. Whilst a lossy compression method, JPG was designed for photos and in practice, JPG can still achieve great results. In recent years there has been a move to improve on this with some cameras providing non lossy systems such as TIFF. Images stored as TIFF are bigger but do not lose any quality. If you have a big enough memory card and the option to save in this format, it is well worth considering if you want the very best in image quality.

Good as TIFF is, it is still limited by the camera's own operating software and ability to process the image data. On a difficult or marginal shot, it can usually be improved upon by taking a step back in the processing chain.

RAW has been around a while now but more and more cameras are now offering it as an option. RAW is quite literally the raw data dump from the image sensor in the camera. It is completely unprocessed in any shape or form. No white balance, no sharpening, nothing. It is not viewable in any meaningful way. RAW files can be quite large though - on a Canon EOS 300D a typical RAW file is 7MB compared to 3MB for a high quality JPG at the highest resolution.

To make use of an image in RAW format, it first needs to be run through some suitable processing software. This takes the raw data and allows the user to adjust different parameters and settings to get the best looking final result. It is analogous to a traditional photographer working in a darkroom. As well as finer control over the white balance, contrast and saturation, these programs also let you extract every last bit of detail out of shadows or reduce the damage from overly harsh highlights. Typically, it can provide an extra stop or so in leeway when producing the image.

Most camera manufacturers provide software to process RAW with the camera. However, this is often less than optimal and a thriving third party market has sprung up providing a variety of programs to choose from.

Some programs have also added RAW support. Adobe have a module that adds RAW support for a range of cameras to Photoshop and Photoshop Elements. ThumbsPlus also now supports RAW along with many others. It's also worth checking the camera manufacturers web site for any updates - Canon for one have something far superior online compared to what gets bundled with most of their camera range.

The biggest problem for developers is that each manufacturer has their own "standard" for the format of the RAW images and it is quite usual for each individual camera to have variations. The result is that every RAW processor needs to have custom code for every camera. As new cameras are released, new code needs to be added making the whole thing a grand game of catch up.

A recent fly in the ointment has been the announcement by Nikon that they were going to encrypt their RAW files making it harder for third parties to write their own processing software. This move has generated a lot of discussion and scorn from photographers everywhere.

One possible solution has been a drive for a true standard. Adobe have been heavily involved with the development of a so called digital negative or DNG. You can read about their efforts here here.

Until recently, the photographers favourite tool for RAW processing has been Capture One from http://www.phaseone.com. This superb but pricy tool allows for batch processing as well as very fine control over the results and is truly in the professional realm. However, a new competitor has arrived in the form of RawShooter Essentials from Pixmantec. This has been developed by some of the same people who developed Capture One but who have now left PhaseOne. In its current beta form, RawShooter Essentials is a free download from Pixmantec. It works well and is being regularly updated and tweaked. It has a few oddities such as setting sharpening to 0 produces some sharpening. It needs to be set to a negative value to get truly unsharpened shots. Apart from that, it is a great tool for anyone whose camera is supported by it.

Workflow

One important area when it comes to using RAW, indeed digital photography in general is the concept of workflow. Workflow is the process by which the images go from the camera to the finished photos. Different people like to work in different ways but here is one possible method.

1. Download RAW to hard drive
2. Backup RAW images to CD or DVD (do it twice for extra safety!)
3. Use suitable processing software to convert the RAW to TIFF or JPG.
4. Delete the RAW images from the hard disk, unless you have acres of free room.
5. If you have a cataloguing program, add the new images along with suitable notes, tags etc to make finding them easier in future.
6. Use your preferred editing software such as Photoshop Elements (you can read a review here) to tweak, crop and adjust the image. Keep each major version of each image as a separate file so you can go back to earlier versions if needed.
7. Print!

Summary

RAW is not for everyone. The improvements are sometimes marginal at best but for anyone wanting to get the absolute best from their camera, it is worth investigating. The extra level of control it gives you when converting to something ready for editing such as TIFF is superior to anything you can do with normal post processing and can often let you save a shot that would otherwise be too dark or light to be rescued satisfactorily.

 

Iain Laskey
See Iain's site at www.pcbookreview.com