Most cameras automatically choose the shutter speed when the camera is set to be on “auto” mode. You can change the shutter speed settings according to you in the “shutter speed priority mode” or “manual mode”. Shutter speed priority mode lets you keep your shutter speed constant, and the camera then adjusts other settings accordingly.
Another reason your shutter speed keeps changing is if you’re using exposure bracketing.
When bracketing for exposure, sometimes one of the exposure parameters – usually the shutter speed – gets changed between frames until the bracket is finally taken.
Exposure bracketing is quite a detailed topic and there are many sub-topics to understand first. However, for this article, we have only mentioned the key topics to get a brief idea of why shutter speed keeps changing, exposure bracketing, and how it works.
Shutter speed affects exposure. It changes the amount of light you capture. The brightness of your image depends upon how long the camera sensor sees the world. We believe that as a photographer, it is always better to try different shutter speeds and explore which one suits you the best in different locations.
If you are shooting all night and need a bright photo, choose a longer shutter speed and stick with it. If you are shooting in daylight and you do not need to use a longer shutter speed, then keep changing the shutter speed as per your convenience.
If you want to capture your object mid-action, a faster shutter speed is recommended. Different photographers have different styles of taking a photo.
For some, setting shutter speed is a priority while it could be the aperture for others. Keeping the shutter speed constant or keeping it changing is completely your decision and will depend on what you are looking to photograph.
Related: Is 1/8000 shutter speed necessary?
Exposure bracketing is a technique where the camera takes 3 photos or more instead of one. The exposure in all these photos is different. One is correctly exposed, one slightly underexposed, and one overexposed. Landscape photographers choose to shoot in this setting. They refer to it as their “safety shots” because one photo will be properly exposed in either of the 3 or more photos. This technique gives the photographers variations of the same image and helps them find the perfect shot.
Depth of field bracketing clicks multiple photographs of objects that are in and out of focus.
Focus bracketing is used to manually adjust the focus of your lens to capture multiple images with a variety of foci. These images can later be combined to form one focused image.
Normally, flash is not needed in a bright background, but in landscape photography, flash is used to light different areas of your image and then compare the shots.
In this technique, one adjusts the white balance of the camera for a variety of colour palettes. This technique is rarely used nowadays.
In this technique, 3 or more photos are taken to find the perfect exposed shot.
This means you keep your aperture and ISO steady while you try different shutter speeds.
Here, you must keep your shutter speed and ISO steady and vary your aperture. This gives variety in your image’s depth of field.
When you alter your camera’s ISO, a high ISO will create a grainy effect or noise in your image. So most photographers choose to keep their ISO as low as possible even during bracketing.
In this mode of bracketing, the camera will provide 3 levels of exposure for a single image. This method allows the landscape photographers to focus on capturing a single image without the trouble of spending valuable time adjusting their settings in manual mode.
This version of bracketing keeps the shutter speed constant and adjusts the aperture to create images with different exposures.
This type of bracketing fixes the aperture setting you choose and automatically adjusts the shutter speed to create a range of short and long exposure shots.
Now you know why your shutter speed keeps changing – it’s because of the exposure bracketing; and whether you should keep it constant or not – depending on what you want to shoot and where you want to shoot. In addition, we have also covered the topics what is exposure bracketing, types of exposure bracketing and how to use exposure bracketing.