Imaging Software, JPEG and RAW

23/11/09

There invariably comes a time in a photographers early development, when three questions arise in his or her mind :

(1) what is this JPEG thing that my camera seems to use, followed by

(2) and what on earth is RAW - which seems terribly complicated.

(3) Imaging software

JPEG

Is probably the most commonly used digital image format available to the market today. Without exception all cameras, be they Point and Shoot or high specification DSLRs have the capability to shot in one or more JPEC modes. JPEG (Joint Photographic Experts Group) is universally compatible with browsers, viewers, and image editing software, and allows images to be compressed by a factor 10 to 20 compared to the uncompressed original with very little visible loss in image quality.
 
The Theory in a Nutshell

Basically JPEG rearranges the image information into colour and detail information, compressing colour more than detail because our eyes are more sensitive to detail than to colour, making the compression less visible to the naked eye. In addition it sorts the detail information into fine and coarse detail and discards the fine detail first because our eyes are more sensitive to coarse detail than to fine detail.

One drawback to editing in JPEG is that on each occasion you edit, close and subsequently re-open to undertake further editing, the quality of the image will be degraded. This can be overcome if the image and all subsequent editing is saved in the TIFF format until the final editing of the image is complete. This is because in TIFF format no compression of the image takes place, whilst in JPEG this is not the case

RAW

Unlike JPEG and TIFF, RAW is not an abbreviation but literally means "raw" as in "unprocessed". A RAW file contains the original image information as it comes off the sensor before in-camera processing so you can do that processing afterwards on your PC with special software. In other words what you are getting is exactly what you have seen when looking through the viewfinder, unlike JPEG where decisions have been made on your behalf by the on board computer chip, and which generally speaking cannot be recovered in post processing. RAW leaves you completely in charge of the image.
 
The RAW Storage and Information Advantages

Each pixel in a conventional sensor only captures one colour. This data is typically 10 or 12 bits per pixel, with 12 bits per pixel currently being most common. This data can be stored as a RAW file. A TIFF file retains 8 bits of information, but will take up twice the storage space. JPEG addresses this issue by compression, at the cost of image quality. So RAW offers the best of both worlds as it preserves the original colour bit depth and image quality and saves storage space compared to TIFF. Some cameras offer nearly lossless compressed RAW.
 
The Flexibility of RAW

In addition, many of the camera settings which were applied to the raw data can be undone when using the RAW processing software. For instance, sharpening, white balance, levels and colour adjustments can be undone and recalculated based on the raw data. Also, because RAW has 12 bits of available data, you are able to extract shadow and highlight detail which would have been lost in the 8 bits/channel JPEG format.
 
Disadvantages of RAW

In my early days of using RAW, some four or five years ago, the processing of RAW images was to a certain extent a little bit of a pain. Firstly you needed to process your image through RAW conversion software ; then import into image manipulation software ; and finally transfer it to cataloguing software. Today however, things are somewhat different, in that both Apple and Adobe have recognised the difficulties in the above process, and launched products such as Aperture and Lightroom which deal with all processes within the one program.

Again in the early days every camera manufacturer produced it’s own version of RAW which required the companies software to convert. Again this has almost completely disappeared as a result of both Apple and Adobe supporting just about every camera that comes to the market.

RAW files most certainly do take up more storage space than JPEGs, but with the cost of cards being what they are today, it is hardly a factor worth taking into consideration.

In conclusion, and in it’s most basic way, what would you prefer, (1) an image that has been tampered with by your in-camera software, pixels that have been discarded, and all of which cannot be recovered, or (2) an image that comes to your computer virtually untouched, with no pixel loss and when even those settings that have been applied, can be discarded.

My own experience with RAW is that once you begin to shoot RAW, there are very few circumstances indeed when you would choose to revert to good old JPEG.

 
IMAGING SOFTWARE

This is a huge subject, and one that ideally should be dealt with on it’s own, and in reality is best approached through the medium of DVD presentation so as to do the subject justice. I will however try to do the best l can to guide people in roughly the right direction.

I am assuming that the most interested reader is going to be one who has come from a compact point and shoot camera to their first DSLR or are in the process of so doing. Up to this point in time you have probably been using software such as Picasa (which is free), iPhoto or some such other like piece of software. There is of course nothing wrong with these packages, they do what they do very well indeed, but they are of course limited.

In software terms the four main packages fall into two sub categories, ie: those with cataloguing and those without and which therefore need cataloguing software.

Those with cataloguing software are Aperture (Apple) and Lightroom (Adobe).

Those without are Photoshop Elements and the full blown Photoshop package, both Adobe products.

There may well be others, such as Corel, but l am confident enough to say that the above are the market leaders and generally speaking the vast majority of photographers use these applications. All the above, with the exception of Corel, provide software compatible with both AppleMac and Windows. Make no mistake, no matter which package you chose, there will be a learning curve to climb, and the tendency is that once you have nailed your colours to a particular mast, you stick with it.

My colours are nailed to the Adobe Lightroom mast and that program will form the basis of the following text. It should, however, be immediately stated that to all intents and purposes Aperture is a mirror image in capability terms and there is almost no detectable difference if what they offer. Photoshop is of course somthing different, but so much of what it provides goes way beyond what l require, that it did not come into the picture when l was deciding upon which route to travel.

What l am trying to achieve in the balance of the article is to give the reader just a flavour of what imaging software can do.

Imaging software - Lightroom. What does it do for you. Well, it catalogues the images for you. You can create numerous folders in which to store your images, by date, by title, by grading, or by whatever you want. I tend to use titles, but you use what suits you best. It enables you to manipulate your image. You can turn it from landscape to portrait ; you can flip it from left facing to right facing ; you can convert it to Black and White ; you can add or take away saturation ; you can crop ; you can increase or decrease the exposure ; you can alter the White Balance setting that the camera applied ; you can add or decrease fill light ; you can add or decrease Blacks, Brightness or Contrast. You can straighten images, or unstraighten them if that’s your wish ; you can remove dust spots, red eye ; you can apply a graduation filter or adjustment brush for Dodge and Burn. The list is almost endless, and the execution is very simple, because all you are doing generally is moving individual sliders.

In previous Tutorials l have touched on the subject of Lightroom Presets, which are filters and or effects which can be applied by one click to an image. As l have said elsewhere there are hundreds of these Presets the vast majority of which are free from various websites, including that of Adobe and which are easily downloadable to your system.

To give you an indication of what can be done, and done simply, l attach below a fairly straight forward image, that has just had a touch of saturation added -
























































Pretty enough, but nothing special. I therefore created a Virtual copy of the image within Lightroon ( as you would expect by now, by way of one click ), and thereafter converted it to a Black & White image using a Lightroom Preset ( again one click ) -























































To my eyes this is an improvement upon the coloured version, and l particularly like the more dramatic sky. However, l feel the foreground is somewhat light, and therefore l darken it using the Dodge (lighten) and Burn (darken) tool -























































I'm now reasonably satisfied with the end result. All this has been done without touching the original image, which remains as downloaded from the camera.

You can see other examples of image manipulation by logging onto the " Short life of unpromising image " Tutorial.

But the real important thing is, that you can never totally and completely mess the image up so that it becomes unusable. Why, because when you are making all these adjustments, you are not amending the original image. It is sitting safely within the system, whilst you fiddle to your hearts content on an exact replica. In other words, it’s idiot proof, and l should know. We’ll say you crop the image, add a bit of saturation, tweak the contrast, the Blacks and exposure. You sit back look at what you have done, and don’t like it. All you do is press the Reset button, and hey presto you are back to square one with your image totally intact.

Once you are happy with your image and wish to print, just press the Print button and this will take you to the Print screen, whereby you will tell the system what paper size you want to use, what quality of print to apply, the type of paper and which print template to use and which printer to print from if you have more than one.

Want to create a Slideshow, then enter the Slideshow module, highlight the images you want to comprise the slideshow and off you go.

The system will even prepare Web Galleries for you if that is what you want.

Quite clearly any explanation about Imaging Software is very much visually based, and as l am unable to produce within this article dozens of screen shots, this particular article is very much at a disadvantage. What l am hoping l have achieved is a feeling that comprehensive Imaging Software is not something to be wary of ; not something to be afraid of, but something to be embraced within your own personal photographic workflow. It is a journey to be welcomed, one to be enjoyed and one that falls firmly within the description of “ Journey of Discovery “.

It is the one tool that will open up a vast new world of photographic experiences for you - if you are prepared to take the first step.

If you are interested in visually seeing more of Lightroom in action, then please e-mail Bob Bell at rafbell@doctors.org.uk, and if sufficient members are interested, then a workshop on Lightroom can be organised.