Light, light, light and more light. That's what you need if you want good photographs.
Cameras need light and the more light the better the picture. When photographing fish you want to wipe the glass down and do a big water change and gravel clean the day before. Wipe the outside of the glass down too to get rid of water drops that glow when a flash hits them.
Open the curtains if it's day time, turn the room light on, make sure the aquarium light is on and use a flash on the camera to get best results.
On some cameras the flash will automatically reduce the shutter speed and this can make it difficult to get a clear picture. Realistically you want a reasonable shutter speed of 1/100 or more to get a picture that isn't blurry.
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If possible, set the aperture (F number) as high as possible so you get more depth in the picture that is in focus. This will make sure all parts of the fish are in focus. I like using F-12 and above. Anything less than F-10 and there is a good chance the fish will not be in focus.
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Have the shutter speed on at least 1/100, but preferably 1/200 or 1/250. This will capture the fish and you won't get blurry images from the fish moving or from the camera shaking when you press the button.
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Set the ISO to the lowest number possible for the cleanest image with the least amount of grain/ pixilation. The ISO usually starts at 64 and goes up to 100, 200, 400, 800, 1600, 3200.
The higher numbers allow the camera to capture images in low light areas but the image gets more pixilated with the higher number. Generally you don't go over 200 ISO for most pictures taken during the day, and fashion models get photographed with 64 ISO. However, the lower ISO number, the more light you need to get a clear picture.
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When you photograph the fish, have the camera on a slight angle to the aquarium and preferably have it just above the fish and facing slightly down. Having the camera on an angle will prevent the flash bouncing straight back onto the lens and causing a big white patch on the image.
Photographing the fish from the front towards the back (head towards tail) will put the light on the fish and give the best colours due to the way the scales reflect light.
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It's all about balance with the camera. The more light you have, the easier it is for the camera film or censors to pick up and record the image, and the better it will be. Fast shutter speeds help and a high aperture number will increase the area that is in focus. And a low ISO number will help keep fine details sharp.
Then takes lots and lots of pictures, look at them on your computer and delete them all before taking more.
