Unintentional blur which is caused by camera movement can take a toll on good photographs. Large amount of camera shake appears as obvious blurs or multiple overlapping images. What many photographers do not know if that small amount of camera shake can soften the image without causing any obvious blurs. Camera shake is best prevented by use of some simple techniques and precautions.
Magnification effect of tele lenses
All the tele-lenses reduce the angle of view thereby bringing in a magnification effect. This is good for closing on to the subject or photographing distant objects. This magnification effect also affects the camera movement. The longer the focal length, the more this shakiness of hands is visible. Add to it the weight of the long teles and the problem is further worsened.
(Old Clocks – 50mm lens at 1/50 sec, ISO at 3200)
‘1/focal length’ rule
A rule of thumb is to use the closest shutter speed number to the focal length of the lens. If the focal length of the lens is 105mm, use 1/125 sec or higher shutter-speed. Similarly if the focal length of the lens is 500mm, use 1/500 sec as the minimum shutter speed. With wide angle lenses like 28mm, a shutter speed of 1/30 will work fine to avoid the camera movement. In the photograph above, I had used a Nikkor 50mm and a shutter speed of 1/50.
Optical stabilization (Vibration reduction)
Over the last few decades, more and more lenses have come out with the facility of OS or VR. These are special optical elements in the lens that do not add or take anything away from the focal length but just shift the image vertically or laterally or both ways to some extent. These are fine optical elements with precision electronics driving them. When activated, these move the image in such a manner so as to counter the movement caused by shaky hands. OS or VR can sometimes give stability to upto 3 full stops. One can then use lower shutter speeds while hand-holding the camera and still get sharp images.
Optical stabilization is not fail-proof. It is useless when it comes to macro photography. Most of blurring that happens in macro photographs is due to the ‘to and from movement’ from the subject rather than lateral movement. Optical stabilization also does not work when the camera shake is due to mirror slap at the time of opening the shutter. While using tripod, it can be counterproductive and cause some amount of blur rather than preventing it.
(Photographed a long time after sunset at an insanely high ISO and post processed in GIMP)
Thanks to the digital sensors, users are no longer restricted to a ISO of the film in use. With advances in technology, inanely high ISOs can now produce acceptable images. The DSLRs now have a function called Auto-ISO. The lenses convey their focal length information to the camera. What camera does is to calculate the exposure and if the shutter-speed appears to be falling below the 1/focal length rule, it automatically enhances the sensitivity of the sensor (increases the ISO). The time when Auto-ISO kicks in is also configurable. Those with steady hands or using any of the stabilizing aids can opt for a lower than 1/focal length limit. I use Auto-ISO at -1, which effectively means that camera pushes the ISO in such a manner that the shutter-speed is never below 1 stop from the 1/focal length. The photograph above from a beach was clicked at Auto-ISO setting and -1EV exposure compensation. Believe it or not but the ISO was 12800! The faint streaks of light on the sand are from a dim bulb hanging far off to the left, behind the beach chairs.
Raising the ISO increases noise. Though the noise performance is very good in new cameras but noise still creeps in. Even an increase of one stop in ISO, from 100 to 200, can create visible noise. So try to use as low a ISO as possible. Noise looks bad but camera shake is worse.
The best support for photographers! They take the weight of the camera and lens and keep them really really steady. Choose a good tripod (Buying a Tripod). Tripods are sold based on their weight bearing specifications. Choose the one that can comfortably take the weight of your camera and lens. Some photographers like to push the tripods beyond their maximum limits but it can be a bad idea especially while using long telephoto lenses which near the weight bearing capacity of the tripod. (Do I use Tripods?)
Once the camera has been secured nicely to a tripod or any such support, the mirror movement (or mirror slap) in single lens reflex cameras that happens before the shutter opens can also be a cause of camera movement. In the film days, the mirror-lock up was the simplest solution. After composing the image, the photographer would press the button to lock up the mirror. The mirror would then rise as it does before an exposure but without opening the shutter. After a few seconds when the camera movement has died down, the shutter is released using a shutter release, remotely. In some cameras, the timer also does the same job. Another trick if you do not have a remote release, use the live-view mode and combine it with timer. Using the live-view option will open the mirror and shutter and the timer will further reduce the chances of camera movement at the time of pressing the shutter release.
These are the single legged cousins of the popular tripods. These are not as stable as tripods but very useful when used for supporting heavy teles, on the move.
To use the monopods effectively, consider these tips –
- Use a ball head for ease of adjustments. Gimbal can be a good alternative too.
- Keep the monopods straight. Chances of movements are least when they are held straight rather than at an angle.
- Use one of your feet to support the side of lower tip of your monopod. Some photographers advocate tilting the monopod so that the lower tip reaches one side of the feet. I disagree. Monopods are steadier when held straight so move your foot closer to the monopod rather than moving monopod closer to your foot.
- Don’t use liveview.
- Use your forehead to support the camera further while looking through the viewfinder.
- If you are using a long lens, use your left hand to support the lens as you would do without the monopod (even if you are using the tripod collar on the lens).
(Deer in a dense forest with very little sunlight reaching the base. Nikon D200 with Sigma 150-500mm set at 500, f/6.3, 1/320 sec at ISO 200 on a monopod)
Yoga for steady hands
Photography gurus have these pointer for holding the camera steady-
- Use whatever support you can find. Sometimes bracing own body can help reduce camera shake.
- Use the viewfinder instead of live-view.
- Take a deep breath before pressing the shutter release button and then smoothly press the shutter release button while slowly exhaling the air out. Do not hold your breath.
- The shutter release should be smooth press and not a jerky stab/jab at the button.
- Follow through the exposure. Wait for the mirror to return before considering the exposure complete. Pressing the shutter release button is not the end of the story.
- Take multiple shots when in doubt. Memory cards are inexpensive but the moment once gone will not return. Do remember to discard all the useless copies afterwards.
What if the photograph has already been blurred due to camera shake or appears too soft. You maybe in luck if you were clicking raw. Photoshop has come out with ‘camera shake reduction’ tool which is quite effective. Search for it under the ‘sharpen’ menu. There are some other companies too that have come out with their versions of this tool. Focusmagic seems to be another good option though I have never tried it. Sharpening will take care of some amount of softness that might have occurred due to camera shake (Sharpening). Resampling and reducing the size of the image also reduces the obvious shake.
Addition of noise (film grain) gives a false sense of sharp image.