Photography Shooting Technique #3: Focus Recomposition

Photography Shooting Technique #3: Focus Recomposition
Requirement: DSLR / Film camera with Autofocus lens
Shooting style: Hand held or mounted on a tripod / monopod
Flash / Lighting: Built-in / Speedlite / Studio or Strobe / Continuous / Ambient
Best Used: NOT advisable; Methods shown in the latter part of the discussion is applicable when NONE of the focus points is directly on the subject to be focused

Portraiture is the most commonly used form of photography. Regardless of location, all you need is a model or simply anyone from the crowd who is willing to pose for a shot. So, given the situation, someone poses in front of you; you aim for the eye; focused the lens as sharp as you can get it to be; BUT suddenly, you recomposed your shot then pressed the shutter button. Upon viewing the picture to 100% size, the eye just got out of focus, then you’ll start asking yourself “why”, and you’ll end up repeating the process only to end up with the same result.

In my two years in photography, I have seen amateurs, and even professional photographers practice those steps. And more often than not in group photoshoots, somebody from your fellow photographers will advise you to focus the eyes. The problem is, upon composing the frame, non of the focus points in your viewfinder is positioned directly to either eye. Such dilemma is, almost all the times, experienced by photographers who use cameras with 1 or 3 focus points, or even on cameras with 9 focus points. This discussion will explain why the subject becomes out of focus after recomposing the frame and the factors to consider to avoid the habit of recomposing your frame after focusing the subject.

Let’s discuss first the “why it happens”:
Please refer to the image below:

Just imagine that this picture of the basketball court, the hoop is the camera; the free throw line is the subject (represented by the blue dotted line); the green line is the initial focusing line of sight; the red line is the recomposed line of site; the yellow line is the depth of field of the initial composition; the purple line is the depth of field after recomposing; and the red dotted line is the new focused plane.

In such scenario, we need to consider 5 factors: the final composition of the shot, the focus points of the camera, the distance of the subject from the camera, the aperture opening of the lens which determines the depth of field, and of course the photographer him/herself respectively.
Final composition and focus point: The subject poses and you compose the shot but it appears that in that composition, none of the focus points is hitting your subject, in this case and most of the times, the eye(s). The tendency is that you would change the angle of the camera then place one of the focusing points over one of the eyes and start focusing it;
Distance of the subject and aperture opening: Once you start placing the focus point of the camera over the subject, the focus “plane” (that’s how I call the imaginary wall parallel to the photographer and the subject) also changes which is greatly affected by the distance of the subject from the camera. The depth of field, however, is determined by the aperture opening. Since you are “recomposing” to place the focus point to the eye, your are also extending the distance of the subject from the camera, like a pendulum effect. So once you redirect the camera to finalize your composition, you have already moved your focusing distance farther. This is when the depth of field comes into play (yellow and purple lines). If you are using a wide opening (lower aperture value such as f/1.8), the depth of field becomes smaller, let’s say to about a foot (12 inches) in front and beyond the subject. A larger aperture value such as f/4.5, on the other hand, will give you a wider depth of field of around 3 feet (estimated values only). Bottom line is, the wider the aperture opening you use, the more likely your subject will go out of focus after recomposing.
Photographer: By the time that you recompose to your final composition, the focusing distance of the camera from the subject has gone further beyond from where the subject is actually standing. This is tolerable if the subject is still within the depth of field, which rarely happens in portrait photography since we usually want our subject to stand out over the background. If you are using a wider aperture opening, your subject will be significantly go out of focus (refer to the yellow and purple lines).

How to recompose without changing the focusing distance from the subject? - This is fairly simple. It all boils down to how the photographer should move:
1. Focus on the subject (i.e. eye);
2. Recompose by moving parallel without changing the angle of the camera. Simply put, move in a horizontal and/or vertical motion as if there is an invisible wall between you and the subject, maintaining your distance from the subject as you move. Please see the illustration below (initial focusing and recomposing, respectively):

Actual example shots below (both images cropped at 100%):

The first image was taken using the usual method as described on the first part of this discussion while the second image (below) was taken using the parallel recomposing and exact same camera settings.

Photography Shooting Technique #2: Using Mirror Lockup

Photography Shooting Technique #2: Using Mirror Lockup
Requirement: DSLR camera with Mirror Lockup (I think all DSLR’s have this, I’m not sure though with Film cameras)
Shooting style: Hand held (Not applicable for use with tripod)
Flash / Lighting: Built-in / Speedlite / Studio or Strobe / Continuous / Ambient
Best Used: For macro shooting; When using slow shutter speed (slowest value may depend on how “stable” you can be); When shooting long range or when using long focal length

In my previous post, we have discussed how to effectively utilize the manual focus in live view shooting to improve the sharpness of the subject to be photographed. In this post, we will be discussing how to use Mirror Lockup to reduce camera shake.

In this discussion, we will be using a Canon 40D with Canon 50mm f/1.8 II lens. The lens may be classified as a prime lens, but due to its focal length, we can also consider this lens as a medium telephoto lens.

What is Mirror Lockup?
As we press the shutter button, 3 components spring into action: the mirror, the first curtain, the second curtain. All these three components move extremely fast which can cause vibration, just like a recoil of the gun after firing. Exaggerated? Maybe. But the slightest vibration may cause camera shake that will ruin your photo. I’m not saying that you need to use mirror lockup all the time nor using mirror lockup will remove camera shake, but using mirror lockup on certain shooting situations may significantly reduce camera shake, thus improving the quality of your shot.

When to use Mirror Lockup?
1. Shooting close up or macro photography;
2. Shooting long range or using long focal length;
3. Shooting using slow shutter speed (“5 – 1/30)
- All situations shooting hand held.

When shooting in condition #3, it really depends on how stable the photographer can be. The more stable the photographer can hold the camera, the longer shutter speed can be achieved.

How does Mirror Lockup work?
In normal operation, once the shutter button is pressed, the mirror moves up, allowing the first curtain to expose, the second curtain closes, then the mirror returns to its original position. Once the mirror lockup is enabled, the shutter must be pressed twice to complete a shot. The first time the shutter button is pressed, the mirror will move up but the second curtain will NOT activate. This prevents the first curtain to expose. The second time that the shutter button is pressed, the second curtain is then activated so the first curtain exposes and the rest of the actions follow (second curtain will close and the mirror will move back to its original position). In this process, the vibration caused by the mirror moving upward is eliminated, reducing the total combined vibration which results to a lesser camera shake.

Can Mirror Lockup replace IS / VR / VC (Vibration Control)?
Depending on the shooting condition, YES. Also, Image Stabilizer (IS) by Canon or Vibration Reduction (VR) by Nikon lens technology increases the monetary value of the lens by almost half of its original value. Not all of us can afford that.

The images below are cropped 100%, the picture on the left side was taken using normal method while the picture on the right side was taken using Mirror Lockup:

Shutter speed – 1/5, Aperture value – f/7.1, ISO speed – 100, hand held shooting

It is clear that enabling mirror lockup when shooting using slow shutter speed reduces the camera shake caused by the vibration of the 3 components (mirror, 1st and 2nd curtains) in the camera.

Note: Amount of vibration reduction may vary.

Photography Shooting Technique #1: Manual Focus Using Live View

Photography Shooting Technique #1: Manual Focus Using Live View
Requirement: Live view function capable DSLR camera
Shooting style: Hand held or tripod (highly recommended)
Flash / Lighting: Built-in / Speedlite / Studio or Strobe / Continuous / Ambient
Best Used: On low light conditions; When AF function does not work properly; When AF function experiences difficulty in focusing

Most DSLR lenses nowadays, regardless of brand, are equipped with AF (Autofocus) function. This allows the photographer to focus on the subject faster rather than doing it manually (Manual focus or MF). As a photographer, I, as well, find using AF the most convenient way in taking pictures, especially when the subject is moving or a sudden moment worth shooting arises which requires an almost instant focusing speed. Different lens brands have put special consideration on the AF function, developing new technology to improve focusing speed such as the Ultrasonic Motor (USM) by Canon, Silent Wave Motor (SWM) by Nikon, Hyper-Sonic Motor (HSM) by Sigma, and Ultrasonic Silent Drive (USD) by Tamron to name a few. Despite all the benefits and efforts put on the AF function, the MF function is still able to find its place in the photography scene, where the AF function meets its limitations.

Autofocus function may have been developed using the latest technologies and materials but it also has its own limitations, and like any other devices, camera lenses may also render inoperable due to mishandling or by “natural causes”. The following shooting conditions may render the AF not to function properly:
1. Shooting in low light or poor lighting condition;
2. Focusing on a plain white / bright or plain black subject without color contrast;
3. Shooting through a glass or water;
4. When a focused subject is seen through a hole or when a foreground “framing” is too small for a focusing point (e.g. shooting the shore behind the leaves, animal inside a cage);
5. When a focused subject is beyond any of the focus points’ reach;
6. When a focus point focuses on a subject with a high contrast of color from dark to bright which causes a fringing effect;
7. When the focusing mechanism of the lens is damaged, faulty, or not working properly

These are just some but the most common situations when Manual focus is the best option to use. A reminder though, shooting in MF mode may oftentimes result in out-of-focus shots. This concern mainly falls into human error, in this  case, the photographer since the photographer is in total control of the focusing of the lens. Since the viewfinder compresses the whole composition (for full frame cameras) into a few millimeters of viewing window, the details of the composition appear to be almost tact sharp, but the miniscule details are actually blurry or out of focus. Another concern that needs to be addressed is the fringing effect, an effect that results to a bluish lining between a dark and bright area in the picture. This effect is not recognized by the AF function and is therefore disregarded and not corrected but in MF mode, the fringing effect can be minimized.

Correcting such imperfections can be done manually, setting the lens focusing mechanism into Manual mode and using the Live view function to view the details in a larger perspective. This is a simple yet effective technique which is best used for shooting still objects, portraits, and sometimes, for shooting landscapes.

Indicated below is a step-by-step instruction on how to use the Manual Focus (MF) mode effectively using the camera’s Live view function:
1. Look at the viewfinder and compose the image to capture;
2. Enable the Live view function;
3. Press the magnify button (with magnifying glass icon) to enlarge or zoom in to the center WITHOUT changing the focal length – use the maximum zoom;
4. Set the lens to Manual focus (MF);
5. Rotate the focusing ring of the lens to achieve the desired focus;
6. Press the magnify button again to view the whole composition, recompose if necessary (If the focal length or distance of the camera from the subject has changed, go back to Step #2);
7. Take the shot (holding the camera as you would using a Point & Shoot camera will result to greater amount of camera shake) or alternatively, disable the Live view function, look at the viewfinder, then take the shot to minimize camera shake. Using a tripod is best for Live view shooting.

The images below were shot using AF and MF respectively and place next to each other for comparison:

Refer to the image above. Both shots were taken using exactly the same Shutter speed – 2 seconds, Aperture value – f/1.8, ISO speed – 100. The picture on the left was taken using the AF mode while the picture on the right was taken using the MF mode. Taking the sharpness into consideration, both pictures are virtually the same. Magnifying the images would tell a different story.

Refer to the image above. Both shots are cropped at 100%. Taking the sharpness into consideration, the picture on the right (taken using MF mode) is considerably sharper, even the texture of the box is more prominent than the picture on the left which was taken using AF mode.

Refer to the image above. Both shots are cropped at 100%. Taking fringing effect into consideration, the picture on the right (taken using MF mode) has a significantly reduced fringing effect compared to the picture on the left which was taken using AF mode.

I find this shooting technique to be effective when the subject is not in motion and when there is enough time available to allow the adjustments and corrections to be made during the shoot.