It is understandable that the sharpest pictures are normally produced by the most expensive lenses. The components used in top of the range lenses are of the highest quality. This more than anything else contributes to pin sharp images.
How sharp you want your images to be is a matter of personal taste. Some people will look at a photo and decide they are perfectly happy with how sharp it looks. Other people can look at the same image with a more demanding eye and think it is nowhere near sharp enough in their view.
It is also worth considering that when you take a picture you may choose to have large areas of the image out of focus in order to highlight the subject of the photo. Even so you will want the in focus portion of your shot to be pin sharp.
Aside from the actual quality of the lens there are a few points worth considering when it comes to the sharpness of your shots.
No matter how much you have paid for your lens the sharpest area of a photo is found in the centre of the shot. Even the most expensive lenses will see a fall off in sharpness as you move away towards the edges. Any loss of sharpness will be more noticeable with a cheaper lens.
Most lenses have a range of apertures. This allows you to change the size of the aperture you are using. Changing the size of the aperture alters the amount if light you are letting come into the camera when you are taking a picture. This can have an impact on the way your photos look.
When you select either the smallest possible aperture to let less light in or the biggest possible aperture to let extra light in, you are pushing your lens to its limits. This can decrease the overall sharpness of your photos.
If you use mid range apertures you will almost certainly see an improvement in the sharpness of your images. The optimum aperture opening for maximum image sharpness is often referred to as the sweet spot. Normally this is found when you are using the mid range apertures around f/8 to f/11.
Although the shutter speed and ISO settings are controlled by your camera and not by the lens you are using it is worth taking time to mention the role they play.
It can be difficult to produce sharp images when you are handholding your camera rather than using a tripod, especially indoors or in fading light. This is because you need to use a slow shutter speed to let in enough light to ensure your photo is light enough.
This makes it difficult for you to hold the camera steady all the time the shutter is open to let in light. If this is the case try increasing the ISO setting and using a faster shutter speed. There is a balance when you increase the ISO setting as this can increase noise levels in your photo.
Another alternative is to use flash if your subject is within range of your flash unit. The burst of flash light will allow you to use a much faster shutter speed. This will result in a sharper photo.
Camera Lens Introduction
Buying Your First Lens
Camera Lens Types
Camera Lens Brands
Buying Second Hand Lenses
Digital SLR Crop Factor
Caring For Your Camera Lens
Common Lens Faults
Camera Lens FAQs
Any imperfections in the lens will be more noticeable if you use a Digital SLR with a full frame sensor. This is because the large size of the sensor will capture extra detail. If that detail is soft then that is how the image will be captured and displayed.
Camera shake is the bane of a photographer's life. It doesn't matter how expensive a lens is if the camera is not held completely still while a photo is being taken. The heavier the camera and lens is the harder it is to keep everything steady. This is especially true with long telephoto lenses as these are very weighty.
Lowlight is an additional problem as the shutter needs to stay open for longer to capture enough light for the exposure. This radically increases the possibility of camera shake.
This is where image stabilisation comes into play. A lens with image stabilisation built in will compensate against any minor camera shake. Some Digital SLRs have image stabilisation built into the body. If this is the case with your camera then you will not need to consider the extra expense of buying a lens with image stabilisation built in.
Image Stabilisation really comes into its own when you are taking photographs in poor light.
If your lens does not have image stabilisation built in then the simple answer is to buy a tripod. This more than any other pieces of equipment is likely to sharpen up your images. Carrying a tripod around is not always a convenient option. If this is the case, look out for somewhere like a wall that is large enough to rest the camera on while taking your photo. Where possible trigger the shutter through either a cable release or the self timer.
This may sound obvious, but careful handling of your lens is of paramount importance. If your lens is dirty then make sure it is cleaned correctly to avoid damage.