Tag Archives: triangle

The triangle of photography

So I’ve been thinking about the subject of the next text. It will be about the three basic things you need to understand if you want to shoot in manual mode with your camera. I will try to explain it in the aquarium photography set-up.


This will give you the ability to choose the amount of light that will reach your sensor. On your camera it will be marked with an f-number (f2.0, f2.8….f7,1…f28). The lower the number the more light that will reach your sensor and the smaller the dept of field will get. So the subject will be very sharp and everything behind it will be very blurred.


A higher number will create a bigger DOF (depth of field). So the subject will be sharp too but you will see more of the background.
 Especially with macro lenses you will have a blurry background most of the time, but you can play with the amount of blur. In the next example you’ll see a sharp shrimp but on the background you can still recognize a snail.


In the world of photography they also use ‘bokeh’ instead of DOF.


This one is very important, especially because in aquarium photography you can’t use a flash because of the reflection in the window (or personally I think it’s not good for the shrimps and fishes). So you’ll have to work with the light that comes from the aquarium installation.
So with less light you will need a longer exposure time on the sensor which is difficult with fishes: you will need very high shutter-speeds because they are moving all the time. So on the next example you will see my shutter-speed was fast enough to freeze the shrimps on the spaghetti stick but not fast enough to have a sharp image of the swimming shrimp on the right side.


Long story short:

  • fish or swimming shrimp = high speed
  • sitting shrimp = lower speed


This one is more difficult to explain but I will try. The ISO will determinate how fast your sensor will react on the light.
 So if you have lots of light, for example on a sunny day outside, you always work on the lowest value possible (iso 100).
 Since it’s never sunny in an aquarium 🙂 you will have to raise up the iso value because of the poor available light.
 So the trick is to keep it as low as possible. I never go higher than 1600. The higher you go the more noise on the picture will get visual and that is not nice to see. With software you can remove the noise but it will never be perfect. Here an example with and without software help on a picture with iso 1000.
Click on the picture for a full size view.



 When you use software try not to use too much editing to avoid having an unnaturally looking result.

The triangle:

After shortly explaining the three things of the triangle, you have to try to understand how they react on each other. 
For example on the last picture the triangle was:

Diafragma f10
Shutter-speed 1/5 sec
Iso 1000

With those settings on manual mode on my camera, the built-in light meter showed a slightly underexposed image (I always do a little bit underexposure to keep the colors nice).
 So for example if the shrimp would be moving more, I would be able to use the next setting to keep the same result:

Diafragma f4
Shutter-speed 1/15 sec
iso 1000

In this case I have chosen a lower diafragma number so more light can reach the sensor. That means I can raise up my shutter-speed because the movement of the shrimp. I didn’t touch the iso setting. By opening my diafragma I will not have such a nice dept of field, especially in this example it is nice to see the moss on the background too. Another solution can be:

Diafragma f10
Shutter-speed 1/15 sec
iso 3200

What will happen now? You will keep the nice DOF and you will have enough speed but your image will have a really high noise problem.


If you change the value of one of the three options, it will have an impact on the other two. The built-in light meter is your friend to give you an idea how the picture will look before you push the trigger. Of course we live in a nice era of digital camera so you can also take a lot of pictures and with the preview on the little screen you can see what the problem is and adjust the settings.

I hope you enjoyed reading this and it made things more clear for you.
Don’t hesitate to contact me if u have questions 🙂


Studio Skwit