Introduction

The best and most versatile option for most non-specialist photography is the digital S.L.R camera because it offers full manual control of all the cameras settings and has interchangeable lenses for different typed of photography
The camera can be used in fully automatic mode for taking general holiday type photos or a mixture of auto and manual settings to cope with some awkward conditions and finally it can be used in full manual mode which allows the photographer to set all the controls in order to achieve the best photo under difficult circumstances.

Point and shoot cameras are generally configured to take good snap shots and tend not to work very well for specialised fish photography. It is possible to take the odd good shot with practice but expect a lot of rejects with this type of camera. Prosumer cameras are an intermediate between the two and usually capable of taking good shots of fish with a little practice from the photographer.

Fish photography

Is difficult, this is because a particular set of problems faced when photographing fish.

Low light: Although most fish tanks appear to be well lit, most are In fact quite dull. This means if auto settings are used there will be a great deal of motion blur as the shutter speed is slowed down to allow more light in.

Moving Subjects: Another problem with fish is that they rarely keep still, which means a fast shutter speed has to be employed or the photo will be blurred.

The subject is behind glass: This creates a number of problems.
a, The auto focus quite often focuses on the glass rather than the fish behind it.
b, The flash will often reflect back off the glass and ruin the photo.
c, Any and every mark on the glass will show up many times worse than it really appears when a flash is used.

To counter these common faults make sure the glass is spotlessly clean and make sure there are no bright reflections on the glass both of these measures will help avoid the cameras auto focus settling o the glass and will help avoid reflections showing in the photo.

Because fish move quite erratically and fast a fast shutter speed is required in order to avoid motion blur, this is where a flash gun makes such a difference because the shutter speed can be set faster in brighter light.

By setting a long focal length even though the fish is moving there will be more chance of getting a really sharp image, again focal length is light dependent so a good flash gun makes all the difference.

Typical Prosumer Camera Functions

Focus Mode Button: Selects either manual focus or auto focus.
Zoom Button: Zooms in or out from the subject.
Exposure Command Button: Used in conjunction with mode dial to adjust the focal length of the camera, f 2.8, f 4, f 8 ect
Info Button: Displays on screen all the current settings of the camera
White Balance Button: Used to select the type of lighting the photo is being taken under, daylight, artificial light, auto ect.
Shutter Button: Operates the shutter to take a photo.
Macro Button: Allows the camera to be placed very near to the subject for very detailed close ups.
Timer Button: Sets a predetermined time lag between pressing the shutter and the photo actually being taken.
Continuous shoot: Takes several photos in rapid succession automatically.
Command Dial: Sets the main mode of the cameras operation, i.e. Manual, auto, shutter priority, aperture priority, low light, ect.
Power Button: Turns the camera on and off.
Flash Button: Selects the different flash modes, i.e. anti red-eye mode, auto, ect. Note this function only works with the inbuilt flash and not with the hot shoe.
Mode Switch: Displays photos already taken on the L.C.D display on the back of the camera or puts the camera ready to use.
Mode Dial: Selects both the shutter speed and the focal length of the camera.

Shutter speed:

A fast shutter speed will stop or freeze movement and a slow one will result in a blurred photo. The very short exposure time of a fast shutter will freeze movement and give a sharp image of a moving subject. The shutter speed required to achieve this depends on three things: The speed of the moving subject, the distance between the camera and the subject, and the angle of movement to the camera.
A slow moving subject (under 5 MPH) less than 5 metres away will need the following shutter speeds to avoid motion blur.

Shutter speeds to freeze slow moving subjects at 5 metres or less
Towards the camera 45° To the camera Across the camera
1/60 sec 1/125 sec 1/250 sec

A fully automatic camera will compensate for the lack of light by increasing the exposure time (slowing the shutter) which often leads to the backdrop being perfectly in focus but the fish which is the main subject will be blurred this is why S.L.R cameras make things a lot easier. But don't forget the faster the shutter speed the more light is needed, simply increasing the shutter speed without sufficient light will only darken the image.

Aperture size:

The aperture size or focal length describes how much of the scene from front to back is in focus, and is measured using the f # the greater the f # the greater the focal length which in simple terms means that a low f # will focus only on the subject the area in front and behind the subject will be out of focus as seen in the example below.

Short focal length Long focal length: At f 2.8 the subject is in sharp focus whilst everything else is out of focus but at f 8
the focal length is far greater as shown by the sharper objects in the background. Some photos work better with a long focal length and some with a shorter one. The type of shot will dictate which looks best to some extent and photography is subjective.
So just experiment and decide which you prefer yourself.

Using a higher focal length makes it far easier to ensure that a moving subject is in focus but when the subject is a particular fish a busy background will tend to make the subject blend in and just as with the shutter speed a longer focal length requires more light.
Unless you are photographing a natural scene a short focal length will make the fish stand out from the background and look more effective but it is much harder to achieve and if it is overdone you could end up where only part of the actual subject is in focus. There are no hard and set rules so try experimenting with different focal lengths to see which you prefer.

A.S.A or I.S.O:

This goes back to the days of film and the number relates to the speed of the film. Fast films (with a higher A.S.A or I.S.O number) can be used in low light levels because they react to light faster and so need less time of exposure but the final result will be a photo which is grainy in appearance and will have more colour noise. Most digital S.L.R cameras still retain this feature even though they don't use film. This allows us to take photos in low light with a reasonably fast shutter speed and a good depth of field which is ideal if you don't have a flash gun and you want to photograph some active fish. The down side is that the higher the A.S.A number the more the final image will be grainy.

Macro Photography:

Using the Macro lens allows extreme close ups which is useful when the subject is a fish like a small Tetra and a detailed shot is required. Most modern cameras have this facility and some of the newer ones can be placed as near as an inch from the subject. This can also be useful for aquatic plant identification and fish disease identification. To use this facility usually requires no more than pressing a button and taking the photo in the normal way albeit a little closer than normal.

Common Mistakes:

Dirty Glass:

A very common error and one which mars some otherwise excellent photos. Easily avoided by cleaning the glass both inside and out but do it at least an hour before taking the photos in-order to allow the fish to settle back down. In some cases the photo can be saved using an image editor and a lot of fiddly work.

Under Exposed & Over Exposed:

Unless you are an adept photographer or you have lots of experience then getting just the right exposure can be a matter of trial and error. Set the shutter speed to around 1/250 sec or even 1/125 sec if the fish are well settled and take a photo if it is over exposed change f 2.8 to the next level up and try again until the right exposure is achieved.
If you want more flexibility try using a separate and more powerful flashgun because shutter speed, focal length and light are all intertwined and alter one will usually mean having to adjust the other two. By being able to control the light you will have far more flexibility than you will have by using the available light and having to adjust to it and be restricted by it. Mild cases can be recovered using a photo editor.

Motion Blur:

Motion blur is caused by the shutter speed being to slow which in turn is caused by insufficient light. This means the shutter stays open longer and if anything moves it will register as a blur on the photo as shown in the example. This is one of the most common of all errors.
The only real solution is to get more light on to the subject or be very patient and wait for the subject to remain still for long enough to take its photo. This error is usually incorrect able.

Out of Focus:

Even with the choice of auto or manual focus digital cameras are more difficult to focus than their film counterparts. One problem is that it takes quite a long time for the auto focus to actually do its job and quite often the fish has moved in the time it takes, if you are lucky it will only have moved a few inches and will still be reasonably close to where it was and a satisfactory photo will result.
Using manual focus is quicker but it is quite difficult because more often than not you are looking at a grainy LCD display and even with a magnification feature in the middle it is hard to tell when something is sharply in focus or not.
One solution is to watch the fish and mark out its regular swimming path, then focus on part and wait for the fish to swim into view.
Even the best image editors can't correct out of focus photos.

Moving Camera:

If the camera moves when the shutter speed is less than 1/60 sec then the image will show some ghosting around all the outlines, this is worse if the subject is further away from the camera. Once the shutter speed is 1/125 sec the problem disappears. In low light situations where the shutter speed can't be increased, the use of a tripod will solve the problem. This is another mistake which usually can't be corrected afterwards.

Incorrect White Balance:

Most cameras have quite a few settings for white balance, there is usually an auto setting which can be used most of the time but it isn't perfect. It is a lot better to select the appropriate setting for the photo that you are taking.
Common settings usually include - Bright daylight, dull daylight, incandescent lighting, fluorescent warm white, fluorescent cool white and custom. These photos can be improved with an image editor.

Poor Timing:

This is almost inevitable when using a digital camera with fish, the solution is to take lots of photos (no film to waste) and the majority of them will be usable. The odd failure doesn't matter. Nothing can be done to improve the photo if the fish has it's back to you.

Reflections:
Surprisingly you often don't notice there is a reflection until the photo has been taken so it is worth making a conscious effort to look for them and then avoid having one right over the subject. If the reflection is caused by a window it won't be a problem if the photo is taken after dusk. A useful precaution would be to turn off the TV and all desk lights before taking the photos and then to check the first few pictures for any other reflections. Image editors are usually quite good at removing these provided they aren't over the subject itself.

Flash Reflections:

Another very common mistake, at first it can seem almost unavoidable but if the camera is angled slightly to the tank instead of being at 90° the flash reflection will be greatly reduced or moved away from the subject to allow the photo to be cropped. If you intend to use a separate flashgun use one which has tilt and turn so that the camera can be used at any angle and the flash itself can be slightly turned away from the subject. Again this error can be corrected provided the reflection isn't over the subject.

Poor Framing:
Try to keep aware of what is in the viewfinder, sounds simple but when the fish aren't co-operating it is all to easy to rush a shot only to discover that part of the subject is missing from the frame. Such photos can only very rarely be saved.

Poor Subject:

However good the photo is technically if the subject is poor so will the finished photo be. The only solution is to be a little choosey about which subjects you take pictures of. The photo in the example was taken in a fish shop and if you look closely you will notice it has White spot, it's emaciated, pelvic fins are almost missing and in truth the fish is probably close to death. I recently saw a Yellow Tang in a similar physical condition and ironically it had just won a photo contest. Which goes to prove that there is no accounting for taste.
An image editor could improve things but the work needed wouldn't be worth the result.

Under exposed	Dirty glass	Poor subject
Reflections	Ghosting, shutter to slow and camera moved	Out of focus
This is how a shot should turn out when all the errors are avoided with a little pre planning.

Other Equipment:

Flashguns:

A good flashgun is almost an essential if you are going to take a lot of fish photos. You will get away without a flashgun if you are photographing a settled, slow moving marine fish in a very brightly lit marine tank without a flash but no flash will severely limit your options. Having one with tilt and turn will help to avoid flash reflections. Unfortunately external flashguns don't work on auto with most prosumer digital cameras but the controls on the back are self explanatory and even using trial and error good photos are soon possible. A dedicated external flashgun used on a true DSLR camera is the ideal choice. Regardless of what you may have been told, flashguns do not scare or harm the fish. I have taken the majority of the photos in this gallery section and I can only recall one single fish even reacting to the flash and that was a goatfish which had been imported on that particular day and so was quite nervous to begin with. A few days later that fish too ignored the flash.

Tripods:

Although not essential they can make life easier when waiting for a fish to come into view, and they will eliminate camera shake when slower shutter speeds are used or if you are stood back from the subject. Most tripods have a built in level so that the camera will be level when taking photos even if the terrain is quite rough and uneven.

Image editors:

Almost an essential thing to have. Even learning the basics will allow you to drastically improve the photos that you have taken and rescue some otherwise useless ones. A good image editor is like having your own digital dark room, common tasks like adjusting the exposure, resizing, blemish removal, cropping are all useful and among the most simple things to learn. More advanced features take a little longer to learn but once you have learned a few tricks your only limitation is your imagination.

Photoshop is the image editor which sets all the standards but it is the most difficult to learn with and it costs in excess of £500. But there are cut down versions available - Photoshop Elements, which lack some of the professional features but still retains all the features that a home user would ever need and it is priced more realistically, some new camera packages even bundle a photo editor free.

Finally:

The best way to find out what works and what doesn't is to experiment, that is the beauty of digital you get instant results and there is no film to waste. Experiment with the various settings make a note of any changes and with experience your photos will improve. And just because someone else's photos always look perfect doesn't mean that they are, it simply means that the ones you get to see are!!!