The most technical issue in a DSLR or SLR is aperture settings. Aperture plays a significant role in photography. All the segments of photography are directly or indirectly dependent on this for the DOF on the frame. Aperture controls the focus area or the DOF throughout the frames. Now we are going to discuss the Critical & Super Critical Aperture setting.
Depth of field
Before starting a discussion on aperture settings, we should know the DOF or depth of field of the frame. Depth of field is basically the focus area on the frame. Sometimes we need to focus only on the subject and sometimes we need to focus throughout the frame. This focus area is called depth of field or in short DOF. Basically, the pin point focus area which creates a clear differentiation from the blur background and foreground is known as depth of field of the frame or your composition.
This DOF plays the main role in the frame where you could create a clear cut of your subject from the background or the foreground. We can decide this focus area from a pinpoint area to all over the frame which can be decided by the aperture setting in your camera. Not only the depth of field is concerned, but other aspects of photography are also affected by the aperture that we can change through the aperture.
For setting the aperture you should set your camera in aperture priority mode or manual mode. You can change the aperture value only through these two modes. The unit of the aperture is symbolized by the small ‘f’ which you will get on the camera control panel. You can adjust the aperture from the top right side with the help of a thumb dial or front control dial.
Increase or decrease or precisely adjust the f value. The f value will be indicated on the control panel. But you should know the lenses because the aperture diaphragm is inside the lens. The shutter speed is inside the camera body as well. Each and every lens indicates its lowest aperture or highest aperture on the body of it. Before using or controlling the aperture of a lens you should know the f value of your camera. The camera cannot decrease the f value more than that. The effect of f value also depends on the camera body i.e. Fx body or Dx body.
Aperture in different cameras
You will get DOF all over the frame in the lowest aperture and zoom out condition or in wide part basically in the DX body but in FX-format you won’t get that effect automatically. You have to adjust the f value in your FX camera but if you zoom then both are the same for the f value. The f value is more effective through all the prime lenses. Always remember when you zoom in, the focus area gradually becomes shallow, and at that time according to your subject depth, you have to increase the aperture or f value. For wildlife photography or product photography, it’s very necessary. For landscape photography, we need DOF throughout the frame so we have to increase the f value. But increasing the f value decreases the shutter speed. Sometimes we need a tripod for the stability of the camera.
The increasing or decreasing of the f value depends on some aspect ratio according to the lenses’ highest or lowest aperture. Here you should notice that I’m not talking about the highest aperture like f22 or f32 but the highest aperture when you zoom the lens. I have mentioned that if you zoom, your DOF area will be shallow. During zooming, most of the zoom lenses’ aperture increases two steps and that aperture will be fixed as the lowest f value at that point.
The two basic points are here for every lens where we get the maximum effects or maximum sharpness of the subject. Simply if we increase or decrease the f value it will not work. The two basic points are the critical aperture and supercritical aperture.
Critical aperture is the two steps ahead from the highest aperture of a particular lens like if a lens consists of the aperture value f3.5-5.6 then f5.6 will be the highest aperture of that lens. You can increase the value with the dial control by using only the two strokes that will be the two steps ahead from the highest aperture f7.1. Most of the time I use this f value as it gives the highest shallow subject depth on the frame. For portrait, street, product, fashion this is the ideal for all and also you will get enough shutter speed as well for freezing your subject and to avoid shaky images. Eighty percent of the time I use this f value for most of the photography.
Super Critical Aperture
The five steps ahead from the critical aperture or mostly the double of the critical aperture is called the supercritical aperture. Near about f11 for the particular lens, we have taken as an example. In this setting, we actually get the highest DOF throughout the frame. But the main problem is the camera reduces the shutter speed because of the shallow aperture. So, there is a chance to get shaky images when you do handheld photography. You can increase the ISO where the sensor sensitivity will increase and the shutter speed will be increased and you will get rid of shaky images.
But in low range DSLR increasing the ISO means increasing the unwanted noise throughout the frame. The recommendation is to use a tripod for this setting. Mainly we need this aperture setting for group photos or landscape photography. During group photos, so many faces are there in so many layers. Therefore, we need each and every face in focus. For the landscape, so many elements are there in so many distances and we need each and every part in focus. So, we should set the f value in the supercritical aperture.
Few important points
For group photos you could use an extra flashgun. So, the camera will increase the shutter speed as you set before the lowest shutter speed during the use of flashgun but in other segments of photography you cannot use the flashgun. Basically, you should think about the shutter speed according to your aperture setting.
The nighttime recommendation is open aperture and also open aperture lenses for the shutter speed. Not only the shutter speed but the open aperture lenses allow maximum light to the sensor. Avoid increasing ISO because it will reduce the sharpness of the images, use prime lenses instead of using zoom lenses.
For the prime lenses after the supercritical aperture of a lens, the sharpness or the DOF area starts to reduce. After the supercritical aperture as much as you increase the f value it will be softer than the previous setting. So, try to shoot in a critical or supercritical aperture when you get enough light source. Nighttime for the DX-format body you may increase the ISO up to 400 but not more than that.
Practice with different depth of subjects and adjust the aperture accordingly, within a short time you will be the master of it. Technibas always wants to hear from your side. Leave your valuable opinion in the comment section. Follow us on Facebook for updates, news, etc.