On many occasions we would like to take sharp photos but fail to do so. Below is a guide about how to maximise your chances of getting a sharp image. While this guide discusses DSLR and similar cameras, we have taken many good sharp images using simple point and shoot cameras by keeping the camera steady and using a fast shutter speed.
A sharp image is reliant on three main things, camera gear, accurate focus and a steady camera or compensating shutter speed.
The right gear
Firstly, to take sharp photos you need gear (camera and lenses) that is capable of taking sharp photos. This requires a bit of research as some lenses sold today are not capable of good sharp images due to design flaws. Most lenses will be sharper in the centre and less sharp towards the corners, however, some lenses lose sharpness quiet close to the centre and should be avoided if you want sharpness across most of your images.
Some cameras are better than others as well.
This requires the purchaser to do some research – our favourite sites are DPReview and Imaging-Resource. DXOmark is too technical for us.
There is also quite a bit of variability, even in top quality lenses – some may prove unusable and need to be returned.
Only high quality filters should be used. Some recommend not using filters but 2 or 3 of our lenses have been saved from serious damage by filters.
Camera limitations and correction functions
The design of mirror-using DSLRs has an inherent weakness that is avoided by mirrorless cameras or shooting in Liveview. This weakness is that the focusing sensors are in a different plane to the image sensor which can lead to minute alignment issues that are critical for sharp images. Mirrorless cameras and Liveview focus on the image sensor.
Middle level and up DSLRs have a function (AF micro adjustment in the Canon world) that, after calibration, allows the cameras to correct for both image and lens alignment issues. It can make a significant difference but is not perfect as the alignment can be affected by temperature and maybe unable to fully cope with zoom lenses that have steps in their actions. Overall, this has been pretty successful for us.
Mirrorless cameras make sure the image is focussed on the sensor, irrespective of any alignment issues in the lens. As we are relatively new to mirrorless cameras we were surprised at a higher hit rate of sharp images compared to our DSLRs, even while learning the basics.
Note that a poor lens remains a poor lens.
Shoot in RAW
RAW retains as much image data as possible, giving noticeably better results than JPEGs from post processing.
Many cameras now have a multitude of focussing points, we recommend that for sharp images of the subject you are targeting that a point focus or the smallest possible focussing area is chosen. These should include cross-type focussing points which are more sensitive. We generally keep our point focus in the middle of the image and first focus on the object then locking the focus to reframe the image. We realize that there are some situations where this may cause issues, but these rarely occur in our photography. Articles suggest that it is more likely in offset portrait photography and then the focussing point should be moved to the position of the target object.
In some situations good autofocus may not be possible – wildlife behind grass. In these cases use manual focus (MF) if your camera will not lock onto the target. A camera with focus peaking in the viewfinder is very helpful to achieving a good focus.
Some mirrorless cameras allow a zoom frame to appear when using spot focus. This frame allows the focus to be checked in more detail and, in some cases, the focusing area to be made smaller.
Steady the camera
Sharp photos require the camera to be held steady compared with the time of the exposure. This can be achieved by using a tripod, image stability (IS) capabilities of the camera/lens, holding the camera in a steady manner and shooting fast enough for the situation.
When using a tripod it is advisable to turn off IS features as they may not recognise the tripod and introduce vibrations. A remote trigger for the camera helps too. In practice, I only use a tripod for night sky images and generally rely on the suggestions below.
Modern IS systems are capable of amazing stability improvements allowing sharp handheld photos to be taken in situations where they would not be possible otherwise. Some caution is required as some camera systems have different IS programs for particular situations, for example panning programs that do not damp the panning action when general IS programs may fight panning. Check that the right setting is being used.
Even without an IS capability sharp images can be achieved by holding the camera in a comfortable braced position against your body and shooting at a speed of 1/125 or faster. Holding a camera out in front of you looking at Liveview image is a recipe for blurry images from camera shake.
Shooting at a fast shutter speed is also important when on an unsteady platform – plane, helicopter, car or boat. 1/250 is the slowest I would use in these situations.
A fast shutter speed is also important for sharp images when shooting moving objects – cars, wildlife sports etc – unless you want to have blur in the image to show movement.
Depth of field (DoF)
For the targeted parts of an image to be sharp, it is important that the DoF is suitable for the situation. Watch for images being fuzzy at small apertures, high f-stops, as the blades of the aperture can cause diffraction rings which stop sharp images being taken. In theory this more likely to be a problem for sensors with high pixel densities.
Use the sweet spot of the lens
Most lenses are sharper when using f-stops that are not at the extreme of the aperture range.
Good post processing can really bring out the sharpness of an image but it can do little to make unsharp images sharp.
We use Adobe Lightroom to bring out the sharpness and detail of RAW files for our images. This is amongst a range of tools we use such as exposure, colour and white balance correction.
The features we use to emphasise sharpness are clarity and the sharpening capabilities of the detail tab. The best settings will take some experimentation but we usually use an amount of 50, radius of 1.5, detail of 25 and start with a masking of 50. Often we make the latter higher so sharpening is limited to the edges of objects in the images. The noise reduction in the detail tab needs to be used carefully as they are largely the enemy of sharpness.
Sharp images are not always possible nor desirable
It may not be possible to take really sharp images in some situations. For example, atmospheric temperature variations distorting zoomed images or through curved windows in some aircraft.
While sharp images can be great, in other situations less sharp images do more to convey the mood of a situation such as during rain, in a mist or an atmospheric bar.