JPEG – the most common file type: You will have seen the .jpg extension on many images it is the most common of the file formats, it derives its name from the creators ‘Joint Photographic Expert Group’ JPEG is the default saving file type for nearly every digital camera, it allows small file size while keeping a high quality image.

JPEG achieves small file sizes by using compression, similar to how a MP3 music file will take assumptions of what the human ear cannot hear and remove those bits - the JPEG file does the same except for bits it determines the human eye cannot see. This process is known as ‘lossy compression format’ whenever you discard digital information be they music bits or photographic bits you have a trade off in overall quality.

Once you have removed information from the original RAW digital image it has gone forever, and as most cameras save in JPEG as default you have lost this information before you have even taken the image off of the camera.

Another downside with the JPEG format is every time you resave the file you are loosing more quality, overall although in the lowest compression mode JPEG produce good results, it can be better to use another format if possible. Furthermore using the JPEG format takes away many of the advanced processing capabilities of the final image once we get to our processing software like Adobe Lightroom or Photoshop to name but two.

Compression – how much do you want to lose?

When you are in your camera settings you will notice you have quality options this will often be represented as Standard, Fine and Superfine or Low, Medium and Best. These settings affect the compression level of the JPEG file format and in turn the final quality of the saved image. To put it simply it governs just how much RAW digital data is going to be thrown away, the higher the compression level the more data you lose and the smaller the file size becomes - allowing for more shots to fit on your memory card. Of course the downside is the higher the compression the lower the final image quality is going to be.

Your camera is making it’s own decisions:  When the camera converts the raw digital data into a JPEG it often looks a little soft or slightly out of focus so to counter this affect the camera has to do a little processing to the image, it will add a little sharpening to the image furthermore it will often enhance the colours to make the images a little more vivid and make changes to the contrast.

This is all fine and dandy and produces images that overall are pretty good and after all they must be ok as most people use them. What is of concern is you have little control over what the camera is doing to your image, you want your images to be saved with as little processing as possible, if you are unable to shoot in RAW because your camera does not offer that format it is a good idea to tweak the setting that govern how the camera will process the JPEG. Nearly all dSLR and compact cameras allow you to adjust the cameras processing settings.

You should be able to change the settings that adjust the sharpness, saturation and contrast; these are typically portrayed in a 3 level choice of -1, 0 and +1 with +1 often being the default. You want to set these to neutral it will depend on the manufacturer of what setting is neutral and you can often find this information out in the cameras manual.

Getting RAW with your photography

RAW files as the name suggest is RAW digital data that is yet to be processed into an image, this is achieved with software that reconstructs the pixels into a viewable image and allows ultimate control on how this is going to be achieved. If your camera offers RAW format there really are no excuses left for not taking advantage of this superior file format.

The benefits of RAW:

I am not about to say shoot in RAW without backing it up with some very valid reasons. A RAW file has captured what you saw before taking the photo without making any changes to it.  Lets say for instance you took a shot only to realise you had not selected the correct white balance, no problem you can simply fix this when you are processing the image. If you had been shooting in JPEG format it is a whole different story and although it is possible to fix the balance it is both time consuming and far from perfect.

Now we start getting deeper into the RAW benefits of exposure latitude. When you save as a RAW format it is normally saved as 12 digital bits, these 12 bits allow for the file to record 4,096 possible levels of variation for every colour. On the other hand a JPEG image stores the image as only 8 bits, the difference at first might not seem like much but it equates to only 256 different levels of brightness for each colour.

Where this really comes into play is in exposure levels, say for instance you have a great shot that is under or over exposed. With a RAW file you can easily adjust one whole stop of exposure with hardly any noticeable affect to the final photo, with JPEG you would be hard pressed to get even close to half a stop. This amount of processing power can allow you the freedom of knowing you can get away with a faster shutter speed in a low light condition and still be able to achieve a correctly exposed shot with in final processing.

A perfectly exposed JPEG photo can never be the same quality as a RAW captured image, the extra bits of data add up to subtle detail and lightning that produce the best photographs.  A final word on the advantages of the RAW format your camera can only do so much when it comes to processing a shot. Processing software is getting better all the time, when you have RAW files you can ever change the final image and with the continuing advancements in technology you are able to turn an ok shot into an amazing shot. Remember once it is in JPEG format your options are severely limited.

TIFF – the ultimate in reproduction

The TIFF format ‘Tagged image file format’ produces the most faithful representation of the photographed image after processing the RAW file.  TIFF is a lossless file format and although still offers some compression it does not discard any data.  Another advantage of the format is the depth of 16 bits per colour channel, compared to 12 bits for RAW and 8 bits for JPEG.

This equates to all the data produced from a RAW file will fit in a TIFF file and truly represent the captured scene. TIFF is by far the best choice for saving your RAW files into for either final processing or printing into stunning large format photos.  If you are doing your final processing in TIFF format you can make large changes to the image without running into the dreaded posterisation and stepping ruining the image.

The only draw back from using the TIFF format is the simply huge file sizes if you take a typical 8-megapixel image you can expect the TIFF file to eat around 40MB of disk space. A best practise for the most stunning and faithful shots is to shoot in RAW save to TIFF for final processing and then to JPEG if needed.

There you have it, now you know how the three main file formats work and how they affect your final image

Photo credits

Intro image by joiseyshowaa