How to Get Sharp Photos
I’ve had a few questions lately asking me about how to get sharp photos – specifically, how and why my photos are consistently crisp. The short answer is that as a professional photographer I’ve had plenty of practice (technique is hugely important) and I’m always thinking about the technical considerations which can influence the final outcome. Broadly speaking, sharp images depend on a variety of parameters which we may need to juggle (and compromise on if we’re shooting in challenging conditions):
Accurate Focus Point Placement
There are several ways a photographer can manage the focusing of his or her pictures. Simplistically, we can hand this over to the camera (as many hobbyists will do using the various automatic modes available to them). And so the camera will generally focus on a close contrasty area. Of course, this may not be the person or thing we want sharpest in our image, and so the photograph may appear mostly soft. Better still, we can manually select a particular focus point. This in turn depends upon our own ability to place that focus point on a relevant part of our subject (for any camera to gain accurate focus it’s generally true to say that the area under the focus point needs a bit of contrast and sufficient light for the area to register).
Your chosen shutter speed must be relevant to either an appropriate handholding speed (for static or mostly static subjects) or else it must be appropriate to the level of movement exhibited by your target. You may want to freeze movement by choosing a high shutter speed, or purposefully introduce some background blur by panning at a lower creatively influenced speed. More on this in the points below.
Adequate Hand Holding Skills
As a general rule, the longer your focal length, the higher your handholding speed will need to be. The ‘rule’ I refer to is the often quoted 1/focal length sec rule. This suggests that a focal length of, say, 100mm would usually require a shutter speed of at least 1/100 sec to avoid blur caused by camera shake. In fact there is a lot of variance with this – we also have to take into account whether or not our lens is stabilised, or if the camera body is for that matter. Stabilisation can enable us to claw back around 3 stops depending on your system. It has to be said that everyone is different. Some people are shakier than others, perhaps by virtue of their age, medication, coffee consumption, or individual natural variance. Some people find it easier to steadily hold a heavy camera and lens due to the balancing effect of its heft, whilst others will do better with more lightweight equipment. In ‘slow’ situations it makes sense to brace oneself where possible, perhaps against a wall or fence. But technique is also important – we need to hold our camera correctly, bracing it against us, and it can help to squeeze the shutter after we have exhaled. It’s worth putting a bit of practice into this, it does make a difference. I remember my original Canon 5D MkI – the mirror slap on that camera was considerable and eventually I learned to get around it by exerting opposing diagonal force with both hands.
If we encounter a subject which is moving then the shutter speed needs to be considered – fast-moving animals or birds can necessitate shutter speeds of around 1/1000 sec, and a model pacing along a runway might need 1/450 sec. Leaving these decisions down to the camera, by using automatic modes, will usually be unsatisfactory simply because your camera won’t know what you’re photographing.
Depth of Field
This will encompass variables such as focal length/magnification, subject to camera distance, aperture choice and sensor size. I’ve noticed something of an obsession these days with shallow depth of field. Your plane of critical focus will become narrower the greater the magnification (and therefore the closer you move towards your subject), and narrower still as you widen your aperture. This means we have to take extra care with both our technique and the placement of our focus point. For most of my work I can rely on focusing and then re-composing (or moving my focus point around if that’s more appropriate). If the depth of field is very shallow the plane of critical focus can move slightly when we recompose, likewise if we move when doing so. Consequently, if our subject isn’t particularly close to us we will usually have a little more leeway.
The autofocus mechanism of most cameras rely upon contrast detection, so we need enough light for this contrast to show up. If our subject is in very muddy or dim light then even the best camera will struggle to gain accurate focus.
As just mentioned, this can influence depth of field/plane of focus.
Most lenses aren’t completely sharp wide open and will benefit from being stopped down a little. Having said that, my Micro 4/3 lenses are all very sharp wide open – perhaps because of the way they are optimised for a particular image circle.
Some lenses are faster to focus than others and some lenses may be less accurate than others. This may partly lie with calibration issues (copy variance) or it may be a factor of the lens type. Usually the longer the lens, if it’s a super zoom for example, the more focusing anomalies can become more prevalent (particularly at the longer extremities). It’s also true to say that some very fast prime lenses may not focus quite so well – but we also have to take depth of field into consideration.
Post Processing and Sharpening
Some newer photographers are inclined to feel that soft images can be remedied by sharpening (either within the camera’s JPEG settings) or afterwards in postproduction. This can be a catastrophe, leading to artefacts and increased noise in some parts of the image. On the few occasions I shoot JPEG, I switch the in-camera sharpening down to its lowest setting – you can always add a bit of sharpening afterwards if you need to, but you can’t undo an over sharpened picture. I’m often asked how I sharpen my images because they appear so crisp. In fact I don’t do any output sharpening for web display, and I apply only the minimal default sharpening in Lightroom when I process (this is something like 0.3/30). I also have a tendency to reduce clarity because I don’t particularly like overly crisp images, especially if they’re portraits of people.
All in all then, there are lots of things we need to think about if we want acceptably sharp photos. Soft images are rarely a result of poor hardware, but mostly a lack of understanding of the parameters we’ve just talked about. That’s not to say that some lenses aren’t sharper than others – of course they are. But with good technique even the most humble kit lens should be very satisfactory. Often lenses are judged according to how sharp they are, but in fact there are several characteristics which can make a lens pleasing. Some of my favourite lenses would probably be poo-pooed by many of today’s hobby photographers, who want or expect biting sharpness right through the frame.
I’m more concerned with how a lens renders colour, contrast, the quality of the outer focus areas (usually referred to as ‘bokeh’). Consequently there are lenses we might choose for architectural photography (or macro work) and others which might be better suited for portraits. For example, I really like the rendering of the cheap and cheerful Olympus M Zuiko 45 f1.8 – this is beautiful shot wide open, sharp but not gritty. Then there is the Panasonic 35-100 f2.8 which is a colourful contrasty lens, very sharp, and great for events or pet portraits. Never underestimate the importance of personal taste. Like most things in photography getting sharp photos means getting plenty of practice – the more you do it, the more you learn, and the easier it gets.
Incidentally, getting your photos to look sharp online is a whole other ballgame. They need to be the right size, but with today’s multi-device viewing platforms a sharp image on your PC can look soft when uploaded and viewed in your web browser. The same image can look sharp on a tablet.