On this page I would like to explain some basics of photography.
I know there are numerous websites on which this information is described, but on this page I will try to explain it in a very simple way and by using pictures to clarify it all.
Currently, I’m using a micro four thirds (MFT) camera because these cameras and their lenses are somewhat smaller and lighter than their equivalents for APS-C or full-frame (FF) cameras. (I used to take pictures with an APS-C camera of a well-known brand.)
The image quality delivered by these different types of cameras are all alike in my opinion. For me the brand of the camera doesn’t matter that much. Lenses are much more important for the image quality and here the rule remains that lenses that are built with high grade glass are much more expensive.
All pictures displayed hereafter were taken using a micro four thirds camera.
If you want to compare the aperture or focal length for the different types of cameras, you need to multiply the values listed under the pictures with 1.3 to convert them to APS-C and with 2 to convert them to full frame.
What is aperture?
The aperture of a lens determines how much light can pass through the lens and reach the sensor. The smaller this number is, the larger will be the opening through which light can pass. The larger the opening is, the shorter will be the exposure time. But as well, the smaller this number is, the more limited the depth of field will be.
The aperture is expressed by an “f” followed by a number. The smallest possible number is 1 (the largest opening) and this continues to (mostly) a maximum of 32 (the smallest opening) according to this sequence: 1 – 1,4 – 2 – 2,8 – 4 – 5,6 – 8 – 11 – 16 – 22 – 32.
For each of the pictures below, the focus was each time on the rightmost bear.
What is focal length?
The focal length of a lens (expressed in mm) determines how much of your environment will be captured on the picture. The smaller this number, the more you can capture using a single image from your environment.
Traditionally, the focal length is given for a full-frame camera. Depending on the number of millimeters the lenses are put in different categories.
- fish-eye: < 16 mm (< 8 mm for MFT) – because these lenses have a very broad viewing angle they will cause barrel distortion
- wide-angle: from 16 mm until 28 mm (8 mm until 14 mm for MFT) – ideal for shooting landscapes
- standard: 50 mm (25 mm for MFT) – these have a viewing angle which is similar to the ones of humans
- portrait: 85 mm (42,5 mm for MFT) – ideal to make portraits of people
- tele: > 100 mm (50 mm for MFT) – ideal to have a object that is far away still pretty large on the image
Als you will see in following pictures something else is happening with the increasing millimeters. When you look to the picture that was taken with the wide-angle, you will see that the bears seem to be far away from eachother. When you look to the picture that was taken using the tele, it looks like all bears were approximately at the same distance and therefore the image becomes more flat.
All pictures on this page were taken on the same day without moving the bears even one millimeter. Also here focus was always on the rightmost bear.
On the left side of the pictures displayed hereafter I moved back with the increasing millimeters in order to capture approximately the same image.
On the right side of these pictures I staid at the same spot and you can compare the effect on the magnification of the subject with the increasing millimeters.
What is sensitivity(ISO)?
By adjusting the sensitivity of your camera, you can capture the “same” image using a faster shutter speed. The faster the shutter speed the less chance there is for having an unsharp image (because of you, the wind or movement of the object).
This however will reduce the image quality because the higher the ISO value the less detail there will be on the picture. If you only display the photo in a small format, you will not notice this that much. But by magnifying the picture, this will become clearly visible.
What is exposure compensation?
Exposure compensation allows you to adjust the exposure time as indicated by the name. It is expressed in eV and can be both a positive and negative value.
When taking a picture, your camera will measure the amount of light in the image and tries to select the best exposure time. If you are walking in a landscape covered with snow, your camera will see a lot of light and will try to reduce the shutter speed which allows you to see the details in the snow. But maybe the snow is not the most important part to you. Maybe you are only interested in the person that walks in the snow.
By letting your camera decide automatically, chances are the person will be pretty dark. By increasing the exposure compensation you can adjust this and you will see more details of that person. The snow however might become totally white.
Whenever you are trying to take a picture of someone in a dark environment, your camera will take the dark environment into account and it will select a longer exposure time which allows you to see more details in the dark part. Again, this might not what we want as the subject is more important. In a dark environment you will therefore have to decrease the exposure compensation.
The pictures hereafter hopefully clarify this. On the left side the pictures were taken using a dark background. On the right side the pictures were taken using a white background. De amount of light on the subject was constantly the same. Nevertheless you will notice that the pictures with the dark background have much longer exposure times.
You will see as well that with the dark background the subject is way too bright using the neutral exposure.