Don’t let camera shake ruin your images. Learn about the handheld rule. Find out what you need to know to protect your photos!
Why worry about camera shake?
- Photoshop is capable of repairing many flaws and errors, but unfortunately, it can’t fix everything! Camera shake can wreak havoc on the sharpness of any image. Lacking a basic understanding of the exposure triangle, many new photographers fail to realize the significance a steady hand plays in producing a sharp image. Having a thorough knowledge of the relationship between shutter speed, aperture, and ISO is certainly the benchmark of a professional; additionally, having a working knowledge of the exposure triangle will not only improve one’s image quality, but it can also unlock creative potential as well.
Why does my photo appear blurry or out of focus?
- Although many factors may contribute to a blurry photograph, I feel camera shake is by far the most responsible. Understanding how shutter speed affects image sharpness is essential in producing a snappy photograph. In fact, failing to have a shutter speed fast enough to freeze an object in the viewfinder may result in a blurry image. Although some photographers have an unbelievably steady hand, no one is a human tripod; in any case, regardless of how well one can handhold a camera, some level of blur will always creep in. Minimizing the amount of blur is the real trick of the trade.
Is there a difference between motion blur and camera shake?
- Keep in mind, camera shake and motion blur are not the same. Camera shake refers to the blur in an image that originates from the movement of the camera at the moment one presses the shutter release button. Motion blur refers to blur in a picture that comes from the movement of the subject. Regardless of where the “unwanted” movement originates; the result is a blurry image. Note the following examples:
How can I prevent blur in my image from camera shake?
- Although considered the best method for reducing camera shake, a tripod may not always be feasible or desirable. Providing sharper images at slower shutter speeds, image stabilization (IS), also known as vibration reduction (VR), may offer a photographer increased flexibility; however, when it comes to handheld use, technique, and yes, even one’s posture is the most critical factors. This fantastic tool called the handheld rule, also known as the reciprocal rule, will undoubtedly significantly improve your photography. Although advertised, as a rule, I encourage using it as more of a guide; conversely, as with many rules, some may be bent while others can be broken. I do, however, suggest utilizing some form of compositional rules, such as the golden ratio, but under no circumstance should a “rule” stifle one’s creativity. When intentionally introduced into an image, camera shake can add stunning, innovative effects.
What is the reciprocal rule, also referred to as the handheld rule?
- The reciprocal rule is considered a good practice within the world of handheld photography and provides an excellent starting point for obtaining a sharper image. Additionally, the rule suggests that when followed correctly, an acceptably sharp image is possible as long as the minimum shutter speed is equal to or greater than the lens focal length. In short, to reduce the effect of camera shake for hand-held use, do NOT select a shutter speed that is less than the focal length (Understanding focal length) of the lens. For example, at a focal length of 100mm, one’s shutter speed should be at least 1/100th of a second to reduce the effects of camera shake; although a faster shutter speed is even better! Still, it’s just a guide, other factors play a significant role as well, such as your technique (one’s stance and dexterity in holding the camera), the use of image stabilization, and camera’s equipped with crop sensors.
If a faster shutter speed is best for reducing blur, why not just use a high shutter speed all of the time?
- Depending on one’s desired creativity or objective, a higher shutter speed may not achieve the best results. For example, a photographer attempting to maximize the depth of field (DOF) for a particular scene may favor an aperture of f8 or higher (aperture may also affect sharpness); consequently, this allows less light to enter the lens and requires a slower shutter speed to offset the difference. Additionally, other factors such as ISO need consideration as well (also see film speed). Cranking up the ISO to allow for a faster shutter speed may sound like a solution; however, one merely gains sharpness at the expense of increased noise in the image. When it comes to creativity and quality, developing a good working knowledge of the exposure triangle will certainly pay huge dividends to one’s artistic prowess.
Will I get better results with image stabilization (IS) on my lens?
- Some lens manufacturers boast that their image stabilization will allow for shutter speeds that are three or four stops less than one could typically achieve without IS. Although, in my experience with image stabilization, more than one or two stops tend to push the limits of sharpness. Another valuable lesson learned when using a lens with IS on a tripod, forgetting to switch off the IS may introduce blur into your image as well. Unfortunately, one may end up shooting a hundred images before realizing that IS was still active. Yes, image stabilization can improve one’s handheld photography; nevertheless, a sharp image mainly depends on one’s technique, as well as one’s definition of sharpness.
What if I own a camera with a crop sensor?
- To determine the shutter speed on crop sensors, simply multiply the focal length by the crop factor. Check with your camera’s manufacturer for details about the crop factor. Several different sizes of sensors are available in various models such as Nikon’s 1.5x and Canon’s 1.6x crop factors. Remember, just multiply the focal length by the crop factor. For example, when using the handheld rule with a 50mm lens on a Nikon APS-C (crop/DX) sensor camera, the reciprocal rule is 1/focal length x 1.5.; thus, requiring a shutter speed of at least 1/75th of a second.
Does it make a difference if I use a full frame lens on a crop sensor camera?
- This is a topic of much debate, but the short answer is, no; however, the long answer is that regardless of whether the lens is full frame or not, on a crop sensor, the focal length remains the same (click here for more on focal length and crop factor). For example, a 50mm lens (full frame or not), on a crop sensor will give you an angle of view of approximately 31-degrees. So, to determine the correct shutter speed, multiply the focal length by the crop factor. Furthermore, on a full frame camera with a full frame lens, the focal length also remains the same, but the difference is the angle of view. For example, a 50mm (full frame lens) attached to a full frame camera body has about a 46-degree angle of view; therefore, one only needs to apply the reciprocal rule, 1/focal length.
What if I use a full frame camera with a lens designed for APS-C (crop sensor)?
- The short answer, a full frame effectively becomes a crop sensor camera. After placing a DX or APS-C type lens on a full frame body, the camera will shift modes (depending on camera your settings) and essentially turn the camera into a crop sensor body. For example, a 50mm Nikon DX lens placed on a Nikon D800 (full frame camera) will give you the same field of view as a Nikon D3300 (APS-C crop sensor).
Why does the reciprocal rule need to change based on sensor size?
- On the full frame system with a 50mm lens, the subject appears further away (smaller) at a 46-degree angle of view; therefore, blur seems less visible in the image. A 50mm lens on a crop sensor has an angle of view of 31-degrees; thus, the subject appears closer (bigger) revealing more blur in the image. It’s honestly a matter of perspective. Think of it like this, when shooting with a crop sensor, the image appears cropped due to the smaller sensor and therefore appears to zoom in closer to the subject; thus, the same amount of camera movement makes the blur more visible in the cropped image. Multiplying the focal length by the crop factor (equivalent focal length) eliminates this effect in a crop sensor. Although I’m not a physicist; based on my research, this is the best way I can explain it.
What is “acceptable sharpness” anyway?
- Although a subjective and yet another much-debated topic, the definition of acceptable sharpness leads back to the 35mm film days. I think every photographer has an opinion on the subject; nonetheless, how does one define “acceptable” sharpness? As for myself, I prefer to view the photograph either on a computer screen (approximately a 13-inch monitor) or printed at about 8×10 inches. Now, step back and view the image from the perspective of a person looking at a photograph hanging on a wall, if it looks sharp, it’s probably good enough for most of us. The following image was captured handheld at approximately 100 feet:
Out of all this stuff, what do I need to take away from this?
- Remember, camera shake can make your images blurry and ruin a great shot. Image stabilization, tripods, and technique are all valuable tools to consider. Becoming distracted by the minutia of sensor sizes and rules will have you pulling your hair out, just take the picture! Regardless of whether you own a crop sensor or full frame camera, I don’t think you will go wrong with a shutter speed that is 1.5 (Nikon) or 1.6 (Canon) times the focal length. Also for the best results, consider improving other techniques as well. For example, a stable stance will undoubtedly assist any photographer in producing sharper images. Finally, I would suggest limiting your coffee intake, but I don’t plan on heeding that advice either!