Understanding The Focus To Make Your Photo Sharp In Photography

 

The focus:

Before we can start choosing the right aperture, shutter speed, or ISO value, it is important to correctly focus the desired image section. Because all the image settings that you want to make afterwards would be useless if a wrongly focused photo emerges in the end.

Sometimes you feel confident that you have taken a sharp picture with the help of the autofocus. The preview on the camera display also underpins this deceptive impression, as everything there looks at first glance as if the photo is sharp. But if you then transfer your pictures to your home computer in order to rework them full of anticipation, you quickly become disillusioned. All images have a noticeable blurring in full resolution. In a low resolution it is not so noticeable, in a high resolution it is quite annoying. Fortunately, focus problems usually only occur in low light. If you're shooting during the day, you can rely on autofocus if the camera is working properly.

Most cameras have different autofocus modes to adjust the autofocus for different conditions. A distinction is made between “MF” for manual focus, “AF-S” for single autofocus and “AF-C” for continuous autofocus and “AF-A” for automatic autofocus.

In night photography we mostly only take pictures of non-moving objects, which is why the “AF-S” single autofocus is the best choice. With the "AF-S" mode, you can follow moving objects with the camera and the autofocus focuses on this object again and again. This is rarely the case with night photography. When choosing the right autofocus, however, it is also important how many measuring fields you have activated on your camera. With the help of these AF points, your camera uses various methods to determine the optimal focus for your image.

Sometimes, however, the camera also focuses on an area that you do not want to be in focus yourself. Too many activated AF points and an incorrect autofocus mode are often the problem. While portrait photography is used to advertise and work with as many measuring fields as possible, we almost always only use a single active AF measuring field for our photos. Depending on the subject, we then move this one measuring field onto the area to be focused in the image. We play it safe so that our camera only ever focuses on the area that we actually want to be in focus. If you have activated the automatic AF, it can also happen that an undesired area is focused. You can find out how to change the AF points on your camera in the operating instructions for your camera.

If the autofocus does cause problems, you can quickly focus your photo manually. You will find out what you should pay attention to in the next section. In order to avoid focus problems, we have got used to setting the focus manually or checking it very carefully when taking night shots.

Automatic focus:

Depending on the camera or lens, the autofocus works differently well or poorly. It can often happen that the autofocus cannot find a fixed point and cannot focus on the subject. This is due to the sometimes low contrast range or too few structures of light and dark parts in the image section. If there are enough structures in your image section, it is usually possible for the autofocus to bring something into focus. This is the case, for example, with a nighttime cityscape. The many lights and different contrasts make it easy for the autofocus to find the right focus point.

If the subject allows it and the autofocus does its job, then it is advisable to use it. However, it is essential to check a previously taken picture on the camera display and enlarge it as much as possible in order to detect any incorrect focus and thus a blurring in good time.

If the picture is out of focus despite autofocus or if the AF turns a wolf and in the end it stops with a completely out of focus subject, you have no choice but to adjust the focus manually. Don't worry, this is not rocket science and it happens very quickly. Your camera or lens should therefore have a manual focus.

Focusing manually:

There are many ways to set a manual focus very precisely. We would like to explain the possibilities with which we have already achieved good results ourselves.

Focus using the LiveView:

The easiest way is to adjust the focus using your camera's LiveView mode. Most cameras these days already have this mode. It shows the photo you see in the viewfinder on the camera screen.

Use a digital magnifying glass to enlarge the image on the display. Find a place in the picture where you can judge the sharpness well. In the case of a cityscape, for example, this can be the finest structures of masonry or a street lamp. The finer the structures, the better you can judge the sharpness.

First try to use the autofocus to focus on the selected area. If you succeed, switch off the autofocus and switch to manual focus. You should do this so that the autofocus does not want to focus again when you press the shutter button again, because you have already set the optimal focus.

However, if the autofocus does not find a focus point, you have to focus manually for better or worse. However, this should be possible without problems on the enlarged area on your camera display.

If you can't find a clue in your subject to set the focus correctly, turning the focus to infinity also helps. Since the correct focus point for most lenses is a little before infinity, you should simply turn the focus ring back 2–3 mm.

It is best if you simply mark the exact focus point with a small dot on your lens. You can find that out in good lighting conditions.

If the autofocus works, use it. But check on a test photo whether the sharpness is really right. If the autofocus does not focus properly due to the lighting conditions, aim at a bright light source in the area and try again. Then switch the autofocus to manual so that the camera does not want to focus again when the shutter is released. But as soon as you change the focal length, you should also readjust the focus.

Note: If you have adjusted the focus and then change the aperture, we recommend that you check the sharpness again and, if necessary, refocus it. With many lenses, the sharpness changes when you change the aperture. This effect occurs only to a very minor extent, but it is worth focusing again to achieve optimal sharpness.