SOME PURITANS CONSIDER IT CHEATING to touch up your underwater photos on computer. Yet, strictly speaking, we are cheating reality while still in the water - by using flashes or placing wide-angle lenses or red filters on our cameras. What we see after the dive is not what we saw during the dive.
Double exposures, trick photography and touch-ups in the dark room have been regular practice since the dawn of photography, but in the digital world it is easier then ever to correct those aesthetic mistakes. It may even be possible to turn unsuccessful photos into minor works of art.
Your collection of underwater images is restricted only by the size of your memory card, your air consumption and the capacity of your camera battery, so you will soon have quite a collection.
Dont just leave them all lying in your hard drive for occasional viewing on the monitor, because there is a wide choice of ways to display them.
This does demand a little discipline, however. It will save time in the long run if you keep your photos organised well enough to be able to locate what you want quickly. That means weeding, sorting and indexing.

In an earlier article we recommended that you take a massive number of pictures while in the water, but that doesnt mean you need to save them all!
Bring the images up on your PC monitor and force yourself to part with those that are not worthy, without being too ruthless. Hard-drive space may be cheap nowadays, but you dont want to drown in a sea of images.
Try to delete all but one of a set of exposures of a single subject. Take away all those that have technical problems. A seagrass plant might make a nice shot from several angles, but one will be the best. Save two or three that turned out really well if you cant decide, or ask a friend for advice.
By hand-picking like this, you will save yourself hours of touch-ups and lots of computer memory.

Now sort the images, name them and index them in a photo folder. A digital photo document can be output on your own printer, sent to a photo-shop to be printed professionally, published on a website or sent for publication.
You can make screensavers, illustrate club magazines or set wallpaper for your monitor or mobile phone. The only limits are those of your imagination and your computers abilities.
These different ways of using your material call for distinct requirements for photo size and resolution. But whatever the application, work only with a copy of the original file. Before manipulating the photos, make copies and archive the original. Eventually you can protect those files in a read-only format so that they cant be changed accidentally.
Remember to make a backup file on, for example, a CD. One could hold your entire Red Sea dive holiday, another last weeks excursion to the coast.
When copying with a purpose in mind, write this in after the name.

Underwater photography is a difficult art form. You dont have control over all the external factors, as you would in a studio, so even the best of your photos are likely to have small flaws.
These can be touched out, but first, consider why the shot turned out as it did. What could you have done to make it better The best photographers are those who can analyse their work objectively and learn from mistakes.
If you experience continuing problems, work through the images systematically and ask yourself what your strengths and weaknesses are each time.
Youll be surprised how soon you start to see better photos appearing on the digital plate.
Its time to start fixing. When you bought your camera, you will have received an archive and photo touch-up software program. If its a good one,you can use it. Otherwise, go for a more advanced professional program. A portion of the price of your camera will have gone towards the program, which is why these are not always top quality.
Recommended photo-correction software includes Adobe Photoshop, Adobe Elements and PaintShop Pro (PC only). And several camera manufacturers have their own software: check out Archive Software, Photoshop Album, ACD See, Fotostation, Fototime or IPhoto (Mac only).
Procedures and methods vary, so study the user manual carefully. There are also many excellent books on the subject. Here we have scope only to cover five basic photo correction modes which you will need to understand whichever program you use. Have fun with underwater digital!

Name, grade and serial number
Perhaps youre planning a trip to the Red Sea, and can see yourself filling the memory card on at least every other 15 or so dives. You could have some 1500 photos to take home.
It would be easy to name the whole file red_sea_2005 for future reference, but it would also be useful to separate the photos into categories - wreck, divers, fish, creepy-crawlies and that side-trip to the desert.
The solution is called meta-information. Engrained in every digital photo, this includes the date, camera, aperture, shutter speed, focal length, resolution etc - and you can add your own personal notes. The genius behind this is that the meta-information functions as a searchable database and the data can be retrieved and formulated in various programs.
You can also index the images in a computer operating system, such as Windows XP.
Most of the archive and index programs have the added function of a virtual light board with thumbnails of the photos, making it quick and easy to search or sort them
So your 1500 photos can be laid to rest in a file named red_sea_2005 and at the same time be indexed down to the most minute detail.

1. The snowstorm effect (Backscatter)
We have explained how to avoid, or at least reduce, the problem of snowstorm photos. The white spots are a reflection of the flashs light on particles in the water. However careful you are, this irritation cannot be altogether eliminated.
One of the oldest tricks is to darken the photo where the snow appears. By toning down the snowstorm, you can shift the focus of the onlooker to the subject.
Another, more effective, solution is to work with a photo-correction programs cloning tool. You can copy a tiny clip of the photo that is free of backscatter and paste it over the white particles.
The smaller the clip, the more discreet the results will be. The work is laborious, but it gets faster with practice.
Adobe Photoshop 7 has an advanced function called the healing tool, which also takes into consideration the structure around the area being worked. The result looks more natural.

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View with backscatter......and with the snow cleared away

2. Cropping
Best results are obtained by composing a photo at the time of shooting it. You know about getting as close to your subject as possible - this gives you more information when you later touch up the image. But perhaps you have a distant shot containing your dream subject, in which case you can crop it.
Many magazine pictures have been severely cropped. The point is to shift the readers attention to the main subject and remove unnecessary information, and often this reveals new qualities in the photograph (left).
If you find cropping your own photos difficult, just try different crops and allow a friend to choose. Remember that you dont have to maintain the subject of the original photo, and you can animate a dull picture by producing a long, thin horizontal or vertical crops, or enlarging a promising section.

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3. Contrast
Contrast may refer to colour, such as a sunshine-yellow fish seen in clear blue water, but more often refers to tone: the difference in brightness between high noon and shadows in a photograph.
If a photo is taken on a grey, dreary day, both the subject and the background will be an even, gloomy grey, because shadows are not really black and the highlights are not really white, either.
The solution is to allow your computer to stretch out the tone scale. It can, if you want, render the darkest portions black and the lightest pure white.
Many photo-correction programs have this as an auto function. With one mouse click it is possible to change the basic corrections, but it is almost always necessary to make manual adjustments.
There are many pitfalls when it comes to increasing the contrast. The result may seem pleasant on your monitor but less so later when it is printed, which is why you need to test your way forward.
Most programs show you a histogram of the photo - a graphic display of how lightness and darkness are involved.
On most cameras these histograms are displayed on the LCD screen and, with a bit of practice, can be used as a guide to adjust the contrast, as shown on this picture of barracuda on the right.


4. Black & white
Many creative photographers work in black and white at the surface - there is something about mono that makes them seem more exclusive.
But with an analogue camera, the photographer must decide ahead of time which rolls of film to load, whereas with digital it is never too late.
Digital cameras can be adjusted to take black and white shots, but its better to do that later on the computer. Try your photos in different versions: black & white, sepia or two-tone. You can also have images in black & white with fragments of colour blended in.
Special wreck shots and more simple photographs with wide tone contrasts can be improved with a reduction in colour, whereas colourful corals tend to look bleak and boring.

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5. Trick or cheat
We have looked at ways of improving your photographs, but technology also offers ways of taking your work into unfamiliar realms. You may want to use the mirror image of a photo to remove distracting objects in the background, for example - although if, for example, you reverse a shot of your buddy, be aware that a regulator hose coming over the wrong shoulder will be a dead giveaway!
A line need to be drawn between touch-ups and all-out cheating. Few would fall for a cut-and-paste photo of a diver swimming among great white sharks, for example. Good touch-up work demands as much experience - and restraint - as taking the photo itself.
There are now special classes in photo competitions for creative manipulated photos and, despite what you might think, creatively touched-up cheat photos can be achieved only with good raw material, loads of patience and a knack for composition. A lucky cheat photo is an accomplishment in itself. Try it - its a good way to practise using your programs advanced functions and finesses.