• Luminance – how the object reflects light
• Illumination – lighting the subject
• Exposure – controlling how much light reaches the sensor or film
• Shutter Speed – the amount of time the sensor is exposed
• Aperture – Like the iris in your eye, it controls exposure and depth of field.
• ISO – sensitivity to light for either the sensor or film (film speed)
• Noise – a bi-product of high sensor sensitivity or higher film speeds
• White Balance – how the camera’s color temperature is matched to that of the subject
• Aspect Ratio – an expression of width by height, 16:9 is an HD aspect ratio typically expressed in pixels, such as 1920×1080
• Depth of field – the band of area in focus away from the sensing element
• High Dynamic Range – HDR imaging is usually accomplished by taking multiple images of the same subject over graduated exposures (from underexposed to overexposed) and merging the highest quality elements from each image to form a single image for spectacular image quality
• Focal Length/Zoom – the arrangement of glass elements in a lens to either magnify or reduce the magnification of a subject
• Macro – the arrangement of glass elements that allow one to focus on items very close to the camera’s sensing element
• Focus – arrangement of the glass in the lens to focus the subject on the sensor

When acquiring an image, it is important to take the appropriate steps to ensure that the subject is well-lit (luminance), properly oriented (composition), and sharp (focused). For digital applications, always check the image taken before moving on.

Lighting

A well-lit subject is desired but not always possible. When your camera, cellphone, or tablet is on an automatic mode, it’s usually going to try and use a combination of settings to obtain an acceptable exposure. The end result is controlling the exposure of the sensing image to portray the subject properly. Controlling the exposure can be done by increasing the time (shutter speed), increasing the aperture (bringing in more light), or increasing the sensitivity (ISO). Each of these impacts the final image in various ways:

• Shutter Speed: With a slow shutter, you will often end up with a blurry image unless the camera is stabilized. You can avoid this by resting your arm or hand on a stable part of the vehicle.
• Aperture: The lower the number, the larger the opening, which reduces the depth of field. This is sometimes desirable, especially when you want all the attention on the subject and don’t want the viewer examining the rest of the image.
• ISO: Increasing the sensitivity will usually result in a noisier image, think “hot pixels.”

Additional lighting tips

You’ll always want to keep the above items in mind when you’re acquiring an image. If the lighting is low and you’re not using flash, you’ll want to stabilize the camera somehow. You can usually accomplish a steady shot by bracing yourself or the camera against a stationary object. This is because low light conditions call for a slower shutter speed. That, coupled with a larger aperture, will reduce your chances of acquiring a sharp image.

Flash: It’s okay to use flash as long as you understand the potential consequences. I prefer to avoid using flash because of the fact that light can bounce or reflect off of objects and produce negative results, such as below.

Auto repair techs often take a photo of the front area of a vehicle with an open bay door as the backdrop. This brings in a lot of light and presents a challenge. Since the subject is “backlit,” it will often end up being underexposed (like the image shown below). In these cases, the camera uses “average weighting” for the exposure. This means the camera takes an average of the light hitting the entire sensor or film frame.

To avoid situations like this, simply modify the exposure. For the case shown above, touch the screen of the smartphone or tablet to focus on the subject area you’d like to capture. Usually, this will present a draggable slider that will allow you to move the overall exposure up or down to enhance the image as shown below.

Composition

Notice the grid overlaid on the image? This can be used to help compose the shot. Placing the area of interest near any of the intersecting lines will usually result in an image that carries a little more appeal. You can usually find the option to turn this on within the camera settings.

Video

Pretty much everything we’ve covered applies equally to shooting video. However, when you shoot video, add narration so that the viewer has a good idea of what you’re demonstrating.

Advanced applications

You can buy several applications that will take your photography operations to a whole new level. Plus, as the technology continues to evolve over the years, so will these applications.

I hope you found this article helpful, as I wish you happy snapping! Please consider joining the Diagnostic Network to help stay attuned with the technical challenges occurring every day within the service industry.