To get the best from digital imaging it is important to know your software. There has to be a starting point of course and there is no better way to learn your chosen image editing software than to set yourself a project and see it through. At the end of that project not only will you have a few good quality prints you will have gained enormous experience. However, there is a stage you will reach when you will be able to look at an image and know straight away if there is a better image screaming to be released. When you reach that stage digital imaging becomes even more fascinating, but until then let Barry help you along the way.

We recently visited Biggin Hill Air fair, but we chose the second day of this 2 day event and yes you have guessed it. Day one was sunshine and blue skies day two was dull and overcast and for shots of aircraft in flight it was a no go. We were shooting with a Nikon Coolpix 950 so had little option, but to concentrate on ground shots between the showers of rain.

At first glance our starting image doesn't look up to much and could easily be discarded. A quick look at the picture also doesn't reveal how much has actually been done to the image, but when you list the tasks it adds up to a surprising number. A lot of the work involves little tricks and tips that can make the world of difference. None of them are difficult and a little practice is all that is required. Using Adobe Photoshop 5 for our manipulation we started off with two images the aircraft and the sky.

If you are adding a new sky to an image leave any adjustment to it until you have it in place with your foreground. You will find that it is easier to get the colour and density correctly balanced when you can see both parts together on screen.

Adjusting the levels to your basic image is important, but for an image shot under these conditions it is vital. Call up the levels palette (Ctrl+L) and give the auto button a try. In many cases it will give a very good result, but after you have clicked the button don't just accept the result completely. Try moving the centre slider at the bottom of the histogram to the right, which sometimes gives a lot more tonal depth to your picture.

This process will also make it a little easier for you to select those areas that you wish to remove.

As usual with Photoshop there are a number of ways in which you can remove unwanted detail. The method chosen will depend on colours, contrast and how fussy the background is. Try a combination of selection commands to find one that suits you and your images best. Remember that you can add to a selection with any of the selection tools by holding down the shift key.

Tip. Remember to rename the default background in your layers palette and feather the edge of your selection by about 2 pixels before you remove the unwanted detail to form your transparency below. Sharp edges will not look convincing.

With your aircraft transparency, sky and layers palette on screen drag the thumbnail of one image into the main picture area of the other and adjust the stacking order by dragging the thumbnails into position. Use the move tool to manoeuvre the sky into the correct position behind the aircraft.

Having done this you may find that the sky just doesn't look right. The shapes of the clouds look OK, but the colour does not suit the lighting conditions that the aircraft was shot in. It looks false and lacking, but not to worry we have a cunning plan.

The aircraft does tend to be almost monochrome in colour, but in blue tones. In this case try reducing your sky to black and white via the shortcut keys of Ctrl+shift+U. If that still doesn't work with your foreground image call up the hue-saturation palette Ctrl+U and tick the colorize box bottom left. Adjust the hue and saturation sliders to balance your sky with your foreground. In this case the settings were about 212 hue and 9 saturation.

This will give you a much more pleasing result, but what about those light areas in the sky, which are a bit too bright. Try covering these areas with a simple selection, feather, copy and paste process.

In a suitable area of the sky make a free hand selection of the rough shape you need to cover and include a little overlap. Feather the edge of that selection by about 10 pixels and then cut and paste this selection to a new layer. Ctrl+C will copy the selection and Ctrl+V will paste it to a new layer for you. Use the move tool to position your new piece of sky over the high light. The amount of feather and where you copy the sky from is important so you may need a couple of tries at this to get the right effect. Once these offending areas are covered you can merge just these layers together, but make sure you do not merge your aircraft as well

Tip. Add a small degree of gaussian blur to your sky to make it look more natural. A close up of this aircraft on a dull day may have this affect anyway. It will also mask any little signs of your sky manipulation and a setting of 3 pixels should be enough. Follow this blur process by adding a little monochrome noise into the sky and a setting of 3-4 should be adequate. This takes away that plastic unnatural look that the blur process creates and will leave you with the result shown below.

You may now think that your picture is complete, but a few more tips and tricks will improve it no end.

Select your aircraft layer and call up the levels palette again. Move that centre slider once more to finally set the depth of tone you require in your image. You may find that it can be toned down quite a lot. Repeat this process with the sky.

One problem that lets down many good pictures is that tell tale line that surrounds some subjects that have been cut away from their background. This is caused by a pixel or two that has come along for the ride, but in some images they may never be seen. It depends on the depth of tone of your background. If you take a critical look at your image greatly magnified you will almost certainly find this effect around your subject somewhere.

Tip. To cover these offending few pixels select your aircraft within the layers palette and tick the preserve transparency box, which is found top left of the layers palette. This restricts any airbrush spray to just your image and will not allow any of it to over spill into the transparent areas. Select your eye dropper tool and with your image magnified select the colour on the aircraft immediately next to those offending light pixels. With the airbrush set to a pressure of about 10 gently colour the light pixels until they match the metal. You will find that this works a treat and you can repeat this around the aircraft changing the spray colour as you move into lighter or darker areas.

Also look critically at the high lights on your aircraft and you may find that some of them while retaining detail are a little too light. Choose the burn tool from the menu bar and from within the palette select highlights and adjust the pressure setting to a very low 3-4. Using a large soft edged brush gently tone down the highlights on the metal body until they become less offending to the eye.

Finally add some darkening to the top of the sky. Either, use a new blank layer and create a small gradation at the top of the frame with the gradation tool set foreground to transparent.

Alternatively make an oblong selection along the top 25-30% of the sky and greatly feather the edge. Adjust that selection using the levels command to darken just the selected area.

Most of the techniques described are the digital equivalent of darkroom processes and this attention to detail and tender loving care will make your images stand out from the crowd and hopefully make them good enough to find their way into the Screen Grabs section of DPFX. Don't rush those images, you spend a lot of money on cameras, storage cards and computers so get the best from your kit.