With growing popularity of digital SLR cameras, more and more people have been not satisfied with the ordinary digital cameras. Digital SLR cameras are no longer the domains of photography enthusiasts. Huge quantity of digital SLR cameras inquire posts can be found in online photography forums. This article was written in plain language so as to help the digital SLR beginners to get practical knowledge in a few minutes.
What is digital SLR
The principle of camera is simple. When you press the shutter, the object image is projected onto the surface of the light-sensitive material media inside camera body. The media records the image and produces the photo. The media is film in traditional cameras. In digital cameras, light-sensitive semiconductor chips (sensor) take the place of traditional films.
What is SLR? SLR stands for Single Lens Reflex. In a digital SLR camera body, a mirror is placed in front of the sensor with 45 degree angle. Usually the object image is projected through the lens to the mirror, the mirror reflects the image to the top of a precision optical prism, this prism makes appropriate adjustments and projects the image through the camera’s eyepiece to the photographer’s eyes. In the moment the shutter is pressed, the mirror is folded, the same image is projected onto the sensor and recorded as digital photo.
To get a good photo, correct exposure is probably the most basic requirement. Underexposed photo looks dim, overexposed photo lost details in highlight areas. Three factors determine the degree of exposure: aperture, shutter speed and light sensitivity.
- Aperture is the optical channel diameter when the shutter is opened. Aperture size is represented by the f value, such as f/2.8, f/5.6 and so on. The larger the aperture the smaller the f value, and vice versa.
- Shutter speed refers to the duration of the shutter open, usually expressed in seconds, say 1/100, 1/300 and so on.
- Light sensitivity means the speed a sensor can response to light. It is often given as ISO values. The greater the ISO value the faster the sensor responses to light. Sensitivity affects image quality a lot. Generally image quality is fine at low sensitivity, but may become worse at high-sensitivity.
When using manual mode, even experienced photographers often use metering tool in order to achieve correct exposure. Ordinary photography enthusiasts may try a simple method: take the first shot using automatic mode, then switch to manual mode and set the parameters based on the first shot data.
The rule of thirds
Photography composition usually follow the principle of the rule of thirds. Suppose we use two horizontal and two vertical lines to divide a rectangle image into nine equal parts. The rule of thirds principle requires that the main object should be placed along these lines or their intersections. People’s experience and visual psychological studies have shown that this composition has better visual effect. However the principle is not a fixed dogma. It is not uncommon to break the principle on purpose according to the theme of the photo.
Many novice are often at a loss when face numerous brands of digital SLR cameras. Generally two considerations should be taken in the purchase of digital SLR cameras, one is the purpose, the other is the budget.
One purpose is for daily family entertainment: to be able to shoot better photos than average digital cameras, play some tricks of photography and capture short movies with video mode. Then the Canon Rebel T5i(700D) and Nikon D5300 are typical cameras of this level.
If you want to develop photography skills seriously, then a camera in between entry level and professional can be the choice. Final decisions depend on the budget. If the budget (camera body only) is around $1000, then the Nikon D7100 and Canon EOS 70D are in this grade; if the budget is around $1500, then Nikon D300s and Canon EOS 7D are in the category.
Usually the manufacturers and merchants provide kit lens with the camera bodies. You may also buy camera body and lenses separately. In either case, the coverage of total focal length should be from wide angle to telephoto zoom range, roughly within 18-200mm. Wide-angle lens is often used to shoot landscapes, buildings, group photos, etc. Telephoto lens can be used to shoot close-ups, such as flowers, pets, portrait, and so on.
In addition to the zoom range, maximum aperture of a lens should also be considered. Some young mothers like to take baby pictures in the room. For fear of harm to the baby’s eyes, they do not want to use flash. In this case, the maximum aperture of the lens is best at f/2.8 or greater. Standard 50mm f/1.8 fixed focus lens is probably the most affordable and cost effective in this category. A zoom lens coupled with a large aperture standard lens is a good choice.
Mentor on your side
It is uncommon for a photography beginner happen to have an photographer mentor aside. In the past two days I went to the district library and found many photography books, fine printed, ranging from entry level to professional. You see, mentor is just on your side.
Due to space limitations, only basic knowledge of digital SLR and photography were shared here. Hope this essay can be a cup of coffee, bring a ray of fragrance to your lives.