Getting your digital images perfectly sharp is something that most photographers want – however clean, crisp, sharp images can be difficult to achieve. Perhaps before we start exploring how to improve sharpness it would be good to talk about the main causes for lack of sharpness:
- Poor Focus – the most obvious way to get images that are ‘un-sharp’ is through having them out of focus. This might be a result of focusing upon the wrong part of the image, being too close to your subject for the camera to focus, selecting an aperture that generates a very narrow depth of field or taking an image too quickly without checking it is in focus.
- Subject Movement - another type of ‘blur’ in shots is the result of your subject moving – this is generally related to shutter speed being too slow.
- Camera Shake – similarly you can get blur if you as the photographer generate movement while taking the image – this often relates to either shutter speed and/or the stillness of your camera.
- Noise – ‘noisy’ shots are ones that are pixelated and look like they have lots of little dots over them (get up close to your TV and you’ll get the same impact).
Here’s a list of 10 basic things to think about when shooting to get sharp images
1. Hold Your Camera Well
A lot of blur in the photos is a direct result of camera shake (the movement of your camera for that split second when your shutter is open). While the best way to tackle camera shake is to use a Tripod there are many times when using one is impractical and you’ll need to shoot while holding your camera.
2. Tripods
A way to reduce (and even eliminate) camera shake is using a tripod.
3. Shutter Speed
Perhaps one of the first things to think about in your quest for sharp images is the shutter speed that you select. Obviously – the faster your shutter speed the less impact camera shake will have and the more you’ll freeze any movement in your shots. As a result you reduce the likelihood of two of the main types of blur in one go (subject movement and camera movement).
Remember the ‘rule’ for handheld shutter speeds:
Choose a shutter speed with a denominator that is larger than the focal length of the lens.
So:
- if you have a lens that is 50mm in length don’t shoot any slower than 1/60th of a second
- if you have a lens with a 100mm focal length shoot at 1/125th of a second or faster
- if you are shooting with a lens of 200mm shoot at 1/250th of a second or faster
Keep in mind that the faster your shutter speed is the larger you’ll need to make your Aperture to compensate – this will mean you have a smaller depth of field which makes focussing more of a challenge (read more on Shutter Speed).
4. Aperture
Aperture impacts the depth of field (the zone that is in focus) in your images. Decreasing your aperture (increasing the number – say up to f/20) will increase the depth of field meaning that the zone that is in focus will include both close and distant objects. Do the opposite (for example moving to f/4) and the foreground and background of your images will be more out of focus and you’ll need to be more exact with what you focus your camera upon. Keep in mind that the smaller your aperture the longer your shutter speed will need to be – which of course makes moving subjects more difficult to keep sharp.
5. ISO
The third element of the exposure triangle is ISO which has a direct impact upon the noisiness of your shots. Choose a larger ISO and you’ll be able to use faster shutter speed and smaller aperture (which as we’ve seen help with sharpness) but you’ll suffer by increasing the noise of your shots. Depending upon your camera (and how large you want to enlarge your images) you can probably get away with using ISO of up to 400 (or even 800 on some cameras) without too much noise but for pin sharp images keep it as low as possible).
6. Image Stabilisation
Many cameras and lenses are now being released with different forms of image stabilisation (IS) which won’t eliminate camera shake – but can definitely help reduce its impact. Keep in mind that IS helps with camera movement but not subject movement as it allows you to use slower shutter speeds (not good for moving subjects).
7. Focus
Perhaps the most obvious technique to work on when aiming for sharp lenses is focusing. Most of us use ‘Auto Focussing’ with our cameras but don’t assume that the camera will always get it right. Always visually check what part of the image is in focus before hitting the shutter and if it’s not right try again or switch to manual focus mode. This is particularly important if you’re shooting with a large aperture (small depth of field) where even being slightly out can result in your subject being noticeably out of focus.
8. Good lenses
This one is for DSLR owners – if you have the budget for it invest in good quality lenses as they can have a major impact upon the sharpness of your images.
9. Get your Eyes Checked
Also connected getting your eyes checked is checking the ‘diopter’ on your camera (if it has one). The diopter is a little adjustment that you can make to how your viewfinder works – it’s particularly useful for people with poor eye sight – it’s usually a little wheel next to your viewfinder.
10. Clean equipment
Keep your camera’s lens clean and you’ll eliminate the smudges, dust and grime that can impact your shots. Similarly – a clean image sensor is a wonderful thing if you have a DSLR as getting dust on it can produce noticeable blotches in your end images.
11. Lens Sweet Spot
Lenses have spots in their aperture ranges that are sharper than others. In many cases this ’sweet spot’ is one or two stops from the maximum aperture. So instead of shooting with your lens wide open (i.e. where the numbers are smallest) pull it back a stop or two and you might find you get a little more clarity in your shots.
