A sharp photo is one of the first things people notice, and a blurry one is one of the first things they reject. But "blurry" can have many causes. The camera may have focused on the wrong thing, the subject may have moved, your hands may have shaken, or only part of the scene may have been in focus. This first lesson of the course explains what focus really is and helps you tell the different kinds of softness apart, so you can fix the right problem.
What is focus?
Focus is the adjustment of the lens so that light from your subject comes together into a sharp point on the sensor. When a subject is in focus, its edges and fine details look crisp. When it is out of focus, the light spreads into soft blurry circles instead of sharp points.
Focusing a lens means moving glass elements inside it so the lens is set to a particular distance: perhaps 2 metres for a portrait, or far away for a landscape. Your camera can do this automatically with autofocus, or you can do it yourself with manual focus.
The plane of focus
Here is an idea many beginners have never heard, yet it explains a lot. A camera does not focus on a "thing". It focuses at a distance. Everything at exactly that distance from the camera is in sharpest focus.
Imagine a giant invisible sheet of glass standing in front of you, parallel to your camera's sensor, at the distance you focused on. Anything touching that sheet is perfectly sharp. This sheet is called the plane of focus.
- Focus on a person 3 metres away, and the plane of focus is 3 metres away. Another person standing beside them, also at 3 metres, is sharp too.
- Someone standing 1 metre behind them is not on the plane, so they are less sharp.
Things slightly in front of or behind the plane can still look acceptably sharp. That zone of acceptable sharpness is called depth of field, which you met in aperture and will study fully in focus distance, depth of field and subject separation.
Remember:Because focus is a distance, the eyes of a portrait subject and the tip of their nose are at slightly different distances. With very shallow depth of field, one can be sharp and the other soft. This is why photographers carefully focus on the eyes.
Five reasons a photo looks soft
When a photo looks soft, it is tempting to say "it's out of focus". But there are several different causes, and each has a different fix.
| Cause | What you see | Main fix | Learn more |
|---|---|---|---|
| Missed focus | Something else is sharp, such as the background or an ear, but not the subject | Put the focus point on the subject | selecting AF areas and focus points |
| Subject motion blur | Still parts are sharp; the moving subject is smeared | Faster shutter speed | motion blur and freezing movement |
| Camera shake | Everything is smeared in the same direction | Steadier hold, faster shutter, support | sharpness from capture |
| Depth of field too shallow | Only a thin slice is sharp; parts of the subject are soft | Narrower aperture or more distance | shallow and deep depth of field |
| Lens or image quality limits | The whole photo looks slightly soft everywhere | Better lens setting, cleaner lens, avoid extreme settings | optical limitations |
How to diagnose a soft photo
Open the photo in playback, zoom in, and ask these questions in order:
- Is anything in the photo sharp? If yes, look at what is sharp. If it is not your subject, the focus missed.
- Is the blur in one direction, across the whole photo? That points to camera shake.
- Is only the moving part blurred? That points to subject motion.
- Is a sharp area there, but very thin? That points to shallow depth of field.
- Is everything slightly soft, with no clear sharp area? Check the lens is clean and the shutter speed is not too slow; it may be a lens or settings limit.
Why sharpness also depends on viewing size
"Sharp" is partly about how a photo is viewed. A photo that looks perfectly sharp on a phone may show slight softness when printed large or zoomed to 100% on a computer. Small focus errors and tiny movements become visible when the image is enlarged.
This is why professionals check important photos zoomed in on the camera, as you learned in viewfinder, live view and playback, and why the standard for sharpness is higher for a big print than for social media.
Where should the focus be?
The part of the photo in sharpest focus is where the viewer's eye usually goes first. So focus is not just a technical choice; it is part of your visual intent. Common choices include:
- People and animals: the eyes, especially the eye closest to the camera.
- Products and objects: the most important detail, such as a logo or the front edge.
- Landscapes: usually a point some way into the scene so that near and far are both acceptably sharp, explained in the depth of field lessons.
Common mistakes
- Calling every soft photo "out of focus": motion blur and shake need different fixes.
- Letting the camera choose where to focus: it often picks the nearest or brightest object, not your subject.
- Focusing on the nose or hair instead of the eyes in close portraits with shallow depth of field.
- Judging sharpness on the small screen only: zoom in to check.
How professionals think about sharpness
Professionals decide exactly what must be sharp before they shoot: an eye, a product label, a player's face. They choose a focus method that puts focus there reliably, a shutter speed that stops the subject and their own movement, and an aperture that gives enough depth of field. When a photo is soft, they diagnose the cause instead of guessing. The rest of this course teaches each of those decisions.
Practical examples
A portrait with a sharp background
- Situation
- Your friend's face is soft, but the tree behind them is perfectly sharp.
- What to do
- You move the focus point onto your friend's eye and shoot again.
- Why it works
- The camera focused at the tree's distance; the plane of focus missed your friend.
- Result
- Your friend's eyes are sharp and the tree is softly blurred.
A blurry photo of a parade
- Situation
- A parade photo looks smeared, and even the buildings are blurry.
- What to do
- You use a faster shutter speed and hold the camera more steadily.
- Why it works
- Blur across the whole photo, including still buildings, means the camera moved.
- Result
- Sharp buildings and much sharper marchers.
Key points
- Focus means setting the lens so light from the subject meets as a sharp point on the sensor.
- A camera focuses at a distance: the plane of focus is parallel to the sensor.
- Softness can come from missed focus, motion blur, camera shake, shallow depth of field or lens limits.
- Diagnose softness by zooming in and seeing what is sharp and what is smeared.
- Decide what must be sharp before you shoot; for people, that is usually the eyes.
Frequently asked questions
What is focus in photography?
What is the plane of focus?
Why are my photos blurry even when focused?
Where should I focus in a portrait?
Conclusion
Focus is about distance: the lens makes one plane perfectly sharp, and you decide where that plane falls. A soft photo can have several causes, and learning to tell them apart is the first step to sharp results. Next, you will learn how autofocus systems find focus and recognise subjects.
Finished reading? Track your progress through Focus and depth of field.