BOOT CAMP 398 (15/11/05)

Pictures on your PC, part 4

As we approach the end of this short series on digital photography we are going to spend the next two weeks looking at image editing, disproving once and for all the old myth that the camera doesn’t lie. It can and has done so since the earliest days of photography, the only difference is that nowadays the lies can be a lot more convincing, and much easier to perpetrate!

Picture editing software has made tremendous advances in the past few years. Early programs were expensive, slow and often difficult to master but these days you can change just about anything on a digital photograph, from eliminating red-eye to removing people and objects from pictures with just a few clicks of the mouse.

Virtually all digital cameras come with some sort of picture editing application and there are dozens of third-party programs on the market, ranging from the industrial-strength Adobe Photoshop to some excellent freeware and shareware titles and they all share a number of common features, a few of which you should get to know if you want to get the most from your digital camera.

However, before we begin commit the following to memory, never change your originals! If you are going to fiddle around with a digital photograph always work on a copy because whilst many programs let you undo changes, once you’ve saved a picture file mistakes can be hard or even impossible to rectify so if you are working on a copy and you muck it up you can always start afresh.

It is difficult to make specific recommendations about which editing program to use, as there are so many to choose from. The freebie software supplied with your digital camera is a good place to start but these are often ‘lite’ versions of more sophisticated applications and therefore limited in what they can do.

For the record the programs that I use most often are Corel PaintShop Pro and Adobe Photoshop Elements, and these can be bought for between £60 and £70 if you shop around. They’re suitable for beginners and more advanced users alike with a tremendous range of easy to use features. My other current favourite is Picasa 2. It is freeware and although it is essentially a ‘viewer’ utility and not as well equipped as most mainstream editing programs it has some superb editing tools.

If you fancy a challenge, and don’t want to splash out on commercial software then I urge you to try The Gimp, which is a powerful Open Source application, comparable with many high-end image editing programs. See this week’s Top Tip for details of other popular programs.

Most digital image editing jobs fall into three broad categories and involve changing, moving or deleting all or parts of a picture, so let’s start this week with a few basic techniques.

Step one is to define your image. If you are happy with the orientation and composition of your picture fine, but quite often it will be in portrait mode -- it appears on its side -- or you want to cut out or crop an expanse of sky or unwanted detail.

The Rotate tool turns the picture, usually in 90 degree increments, though some programs also have a manual rotation facility, so you can turn it a few degrees either way to straighten it up. Cropping is also very straightforward and on most programs you use the rectangular cropping ‘tool’ to define the area of the picture that you want to keep. When you are happy with it press Ctrl + C to copy then Ctrl + V to paste and display the new cropped image. It’s a good idea to use Save As to name and save the new picture.

The automatic exposure systems on modern digital cameras, like their film camera counterparts, can cope with a wide range of lighting conditions but inevitably you will end up with images that are too dark or too bright. Digital cameras can also be fooled by the colour ‘temperature’ or the ambient light -- both natural and artificial -- and a stunning sunset can end up looking pale and uninteresting because the camera is trying to compensate for the abundance of reds in the scene.

All picture-editing programs have adjustments for brightness and contrast, however, these settings act globally on the whole image so they can be quite coarse in their effect. It can be difficult to get the lighting exactly right, particularly if the image has deep shadows or brightly lit areas, in which case it is worth experimenting with more sophisticated tools -- if available -- that adjust highlights, lowlights and shadows separately. Picasa 2 is particularly good in this respect (select the Tuning tab); the effects are really easy to use and you can judge the results instantly in a full screen Preview.

Changing the colours in an image is a bit of an art, and highly subjective. Almost all editing programs have a setting for the overall colour intensity or saturation plus separate adjustments for the red, blue and green colour levels but it takes practice and a lot of fiddling around to achieve natural looking results. Colour corrections should be subtle and it is usually a better to fine tune colour levels with ‘hue’ or ‘tint’ controls. 

NEXT WEEK -- Pictures on your PC, part 5

JARGON FILTER

COLOUR TEMPERATURE

The distribution of colours in a light source, measured in degrees Kelvin. (Typical values: tungsten lamp 2700k, fluorescent tubes 2700 to 6500k, noonday sun 5500k, blue sky 10000k)

FREEWARE

Computer software that is freely distributed though the author will normally retain control and copyright over the original programming code.

HUE

Colour graduation, tint or shade

TOP TIP

More popular Digital Photo editing programs

Arcsoft PhotoStudio http://www.arcsoft.com/

FotoFinish Studio http://www.fotofinish.com/products/photo/studio.htm

Microsoft Digital Image http://www.microsoft.com/products/imaging/default.mspx

Serif PhotoPlus http://www.serif.com/

Ulead Photo Impact http://www.ulead.com/products/digital_imaging.htm

For details of more digital imaging freeware and shareware and picture editing Top Tips go to www.rickmaybury.com.

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© R. Maybury 2005, 0911

Part 1, 2, 3, 4, 5, 6,