digital photos


I first put together a little booklet to explain the basics of digital photos in France for my clients, it was at a time when many people were buying computers to go with their new digital cameras and it was helpful to many who had never done more than take their roll of film to the photo processor and who were now wishing to print their own photos.

Whilst a lot has changed since I first put this together - smartphones and cloud storage - the basics still hold good.

I talk about Photo software and especially Google Picasa, which has been discontinued by Google in favour of their cloud storage solutions. I know that everything has moved to the cloud and their many apps have become the new way of managing your photos. This is great and whilst I might be considered a Luddite as I continue to cling to Adobe Photoshop or its Linux equivalents, I myself prefer to have complete control over the manipulation and storage of my precious images.

When I look at cloud storage one thing keeps popping into my mind, and that is "Out of sight, out of mind", until you suddenly need the photo of a family member, friend or special occasion, and you cannot remember where you stored it and you've changed phone and storage provider a few times since, and on top of that there are literally 1000's (perhaps even 10s of 000's) that have never been sorted and put into folders, and you always meant to print out that photo, but...

Even though Picasa has been discontinued it is still available for download from Google here or you can download it from my site here. It is FREE and extremely easy to use and it might give you a taste for improving your photos.

What is a Digital Photo

It is a photo made up of a series of pixels. Digital photos when viewed on TV's, monitors or smartphones use RGB colours which mean that each pixel has a 256 (0 to 255) colour gradation of red, green and blue. 256 x 3 colours = 16 million colours, visit allRGB to see images that contain one pixel of every RGB colour (16,777,216).


RGB additive model

CMYK = Cyan, magenta, yellow, key (black). The CMYK model works by partially or entirely masking colours on a usually white background. The ink reduces the light that would otherwise be reflected. Such a model is called subtractive because inks 'subtract' brightness from white. Computer color printers (inkjets) use this method.

Pixels and Megapixels

A pixel is a square of colour, next to another square of colour and so on.


a rectangle of 108 pixels which make up part of a photograph

DPI = Dots per inch and PPI = Pixels per inch. You can ignore these other units of measure, nowadays software and hardware are capable of translating all measurements. If you need more information visit About.Com - Getting Started Scanning for an in depth explanation.

Aspect Ratio

Why is aspect ratio and cropping important with the digital photo? With regard to a photo from the Olympus camera its aspect ratio is 4:3, however a traditional 35mm photo film has an aspect ratio of 3:2, this is more often than none the aspect ratio of photo frames, albums and online printing services which translates to a 6" x 4" format (15 x 10 cm).

It is now possible to find 4:3 aspect printing online. If you would like to know more about photo paper sizes and their aspect ratios Wikipedia has an article here.

Photo Cropping

For a digital photo to be printed on a 6" x 4" format it is necessary to crop the image, cropping is literally cutting a bit off the image to make it fit. Modern programmes that come with your digital camera or your printer can do this automatically however they will, in the majority of cases, just cut a bit off the top and bottom (and the sides) to achieve the desired ratio, which is fine if the image you want is nicely centred on the photo.

Therefore if you wish to make life simpler by cutting out the manual cropping process, you must make sure to frame the subject(s) centrally in the camera viewer.

Photo Software

There are many programs that will crop your images, they are bundled with your camera or printer, but they are often limited or out of date versions of commercial programs and each program has its own learning curve for good results. There is however a free program called Google Picasa which is not only up to date but is simple to use for cropping, eliminating redeye, adding text, lightening dark photos etc... It can also be used with the majority (95%) of digital cameras on the market today, this means that when you change camera you don't have to learn another program that comes with the camera.

Screenshot of Picasa cropping page

Backing-Up Photos


Before altering your images please make a backup of the originals if not already done.

Is there a method that is 100% safe? In digital format (for the public with limited resources), probably not! What methods are available? External hard drive, USB stick, CD/DVD, Online storage etc...

Electronic hardware (hard drive/USB stick) can suffer damage or in the long run simply stop working. Online storage can go offline (no longer accessible), you are not in control. CD/DVD can become unreadable if scratched.

In my opinion and with many years experience, I believe that you can perm your favourite method + CD backup (CD not DVD, if a CD cannot be read, the number of photos lost will be 7 times less than a DVD, also CDs are a lot cheaper!).

Use only the highest quality CDs and treat them as you would negatives, handle them carefully and store them in the back of a drawer/cupboard, like that they should remain undamaged, and you can use them to create other forms of backup in the future. For those images that can never be replaced, make a set of top quality prints and put them in a photo album.

Verbatim 43411 (CD-R) Datalife made in Japan/Taiwan are considered to be among the best, they are available from Amazon in 100 spindle packs for £15±. If bought this way you need to put them in individual sleeves or boxes to protect them. My advice - do your own research before buying high quality CDs.