Aperture is coming from the word “aprire” means opening. The aperture settings in a DSLR camera sets the opening of lenses. The aperture is set to gain the best light exposure to display a photo. Not only the aperture must be set also Shutter Speed, therefore a good combination between shutter speed and aperture will produce the best result.
Aperture is measured in f-stop. The aperture of a lens is adjusted by f-stop.
50mm lens with aperture opened to 12.5mm is equals to f-4. (Working 50/12.5 = 4)
Note that the larger the f-stop the smaller is the aperture and the larger the aperture can be set the faster is the lens. Fast lenses allow you to shoot with a high shutter speed in low light environment. in terms of measurements F1.0 – F2.8 are considered high speed. Small aperture is used to achieve high quality results with regards to depth of field, for example shooting landscapes.
The shutter speed controls the duration of time that light passes through the lens. When referring to shutter speed means the amount of time the shutter is opened or the digital sensor is activated. The shutter speed is used to freeze motion, the lower the shutter speed the more blur results we get, the higher is the shutter speed more clear results we achieve. An example setting the shutter speed to freeze blades of a fan or helicopter. The combination of Shutter speed and Aperture settings is known as RECIPROCITY.
Digital Image Sensor
There are two types of Image Sensors known as Charged Couple Device (CCD) and Complementary Metal-oxide Semiconductor (CMOS). CCD was primarily made for video cameras. CMOS made significant improvements in digital photography with its technology, still today CCD is used for video cameras and CMOS for professional DSLR photography.
RAW files and Formats
What are RAW files?
RAW files contain the integral information produced by the Photo camera at the moment the image is captured, such as the following:
- ISO settings
- Lens type
This is known as MetaData.
RAW file properties:
- Colours are not balanced
- The size of the file is large
- More Bit depths (8 to 16 bit)
- An image has all colours that the camera can capture ( not compressed)
- Limited to 8 bit this means that the amount of colours is limited to ADOBE RGB 1998 and sRGB (Color Clipping)
- Can store 8 to 16 bit.
- Retain high colour information.
- Lossless compression.
- TIFF format mostly used for photo printing.
Why the camera shake occurs?
- Slow shutter speed
- Long Focal Length
The above combination is a very slow capturing and the result is a blur and shaky.
- Increase Shutter speed to the value of the focal length
If a focal length lens is 100mm set the shutter speed to 1/100 or faster. Note most of the latest digital cameras have an image stabilizer which helps to solve the camera shake problem.
Lenses When and Why
- Super wide-angle lens
- Options:- Zoom and Fixed local focus.
- 10mm to 20mm, 12mm to 24mm
- 16mm to 17mm fixed
- Zoom telephoto lens
- 300mm and more
- Macro lenses
- Fixed Focal Length Lens
- Range 85mm (F/1.8) 135mm
- Mostly recommended 50mm F1.8 – F1.4
The longer lens allow you to increase the work distance between you and your subject.
135mm preferably used for head and shoulders portraits.
- Any lenses
- In action wide-angle lens
- A spectator from distance Telephoto lens ( Parties, vacations ……)
- Daylight Telephoto zoom lens 300mm range
- Night higher quality telephoto zoom with a wider aperture
- Water-resistant gear.