All photography is reliant upon light, and generally the more of it that you have the better. Whilst modern digital cameras are in some ways more forgiving of the poor light conditions that we as anglers often have to cope with, the same rules apply as they did with film, and very often there are some big compromises to be made.
Digital cameras work by little parcels of light, called photons, activating the millions of photo-reactive cells packed onto the cameras image sensor hidden away behind the lens. The more light there is the more often these cells are activated, giving a better image. We touched on the ISO button on the camera in part 2, and this button basically adjusts the sensitivity of the camera to light. So when the light is really bright you can set the ISO really low, say 100, whilst on grey days you might need to ramp it up to 400 or even 800 to make it more sensitive. The downside of this is that with increasing the ISO comes image noise. Noise is caused at high ISO’s because the camera struggles to tell the difference between different light levels, so it becomes less reliable. This can make the finished picture look grainy, especially once you get about ISO 400.
Fortunately, we are not completely reliant upon ISO to collect enough light, far from it. Actually, I rarely go above ISO 200, as above this image quality starts to fall off quite sharply on the entry-level cameras that I use. If you can afford to spend thousands on a camera then one of the main improvements you will see is how well the camera works under low light and high ISO’s.
Remember on older cameras when you used to hear an audible ‘click’ as you took a picture? That was the shutter opening and closing for a split second to let in just enough light to expose the film. Modern cameras also allow you to adjust the shutter speed, even though some of them have done away with the shutter!
As a rule of thumb, the shutter speed for catch shots should be a minimum of 125th of a second. If it is less than this then slight movements of the captor and fish, and whoever is holding the camera will make the image look blurry. Shutter speed goes right up to 2000th of second, which really is fast, and is only used on really bright days, but as long as you are getting more than 125th then you should be ok if you hold the camera as still as possible.
One useful tip, if you want to ensure that the speed is always at 125th is to switch the top dial to the TW setting. This allows you to fix the shutter speed and force the camera to adjust other settings. We use this setting a lot when filming underwater, as often the light is poor, and we need to fix the shutter speed.
OK, so you have your ISO fixed at 200, and your shutter speed at 125th, unfortunately, there is one other thing to worry about, and that is the F-stop, also known as the aperture. Inside every camera is an adjustable size hole (the aperture) that the light has to pass through. The bigger the hole (which confusingly is given a smaller F-stop number), the more light gets to the sensor and the brighter the picture.
You can think of the F-stop and the shutter speed as working against one another. The faster the shutter speed the smaller the F-stop needs to be; the shutter is open for less time, so the aperture needs to be bigger to let in the same amount of light. Unfortunately, especially with catch shots, there is a price to pay for using a small F-stop, and that is because the smaller the F-stop the narrower the portion of the image that will be in focus.
If you have ever suffered from a nice shot being ruined because you were perfectly in focus, but the fish was slightly fuzzy then this was cause by using a small F-stop, giving a very narrow depth of field that is in focus. This is normally exasperated because we all want our fish to look as big as possible, so hold them towards the camera, meaning you need a big depth of field to cover both you and the fish.
Ideally, you want the F-stop to be in the range of about F8 to F20, once you get smaller than F8 then either you or the fish is going to be in focus, not both. As long as you realise this then it isn’t a major problem, hold the fish close to you and ensure you focus on the fish, and the pictures will be OK.
So to end this month, lets have a quick step-by-step run down of how to set up your camera for a basic catch shot, with the minimum of fuss.
Check ISO – set the ISO to 200, or 400 if it is a really grotty day or you are in a shady spot.
Set the top dial to TW – This allows you to fix the shutter speed, meaning you only have to worry about the F-stop or aperture.
Dial in your shutter speed – Even on really grotty days I like this to be a minimum of 125th if I am holding the camera.
Check the F-stop – If this is much below F8 then remember that only the person or the fish is likely to be in focus. Make sure the camera is focussing on the fish, as this is the most important thing in the shot.
Take the picture!
Phew, I’m sorry if this series has been quite technical so far, but that is all of the boring stuff over and done with now, next month in part 4 I am going to get down to the real nitty gritty and look at how you can take brilliant catch shots of your mates that will have them singing your praises!