DSLRs

Dynamic Single-Lens Reflex Cameras (DSLRs) are the big professional-looking black cameras with the big lenses.
Photography is part of our course structure in our second year.

A few intimidating terms related to photography:

  • Focal length
  • Aperture
  • Shutter speed
  • CMOS
  • ISO
  • Optical/Digital
  • Exposure
  • White balance
  • Frame
  • Focus/Focus points
  • Macro
I will try and explain some of these…
                          10th class Physics. Same thing; the distance from the lens at which light rays from an object placed there will emerge parallel to each other after passing through the lens. Basically the distance till which objects can appear clearly. Objects anywhere else appear blurred. DSLR lenses have variable focal lengths. The lenses have 2 turning rings with numbers and markings on them. One is for optical zoom and another is for focusing. Optical zoom changes the overall focal length drastically while focusing changes it minutely. Every camera lens in reality is a combination of lenses. These rings move the internal lenses back and forth to change the focal length accordingly. Different camera lenses have different ranges of focal lengths. The default lens supplied with DSLRs is mostly 18-55mm. Other lenses are used for other purposes like shooting far away objects or for Macro shots.
                    Like the iris in the human eye, the aperture device in the lens controls the amount of light entering the camera. More the aperture, more the light. Aperture is physically controlled unlike exposure and ISO. Don’t get confused. This controls the light entering the camera itself. It is specified using an f-number or simply a fraction like   /2–/4,   /4–/8  or   /8–/16 .

                           This is directly related to exposure. Most cameras do not allow the user to control both exposure and shutter speed simultaneously and 100% manually. This is because poor knowledge of these and wrong use can cause damage to the CMOS sensor, leaving the camera beyond repair. You may have seen many pictures with trails of headlights or taillights, or may have heard of ‘light painting’. Shutter speed basically means the speed of the shutter :P. To take a photo, the shutter opens and lets light on the CMOS sensor. Then within a split second it closes, allowing the sensor to capture all the light that fell on it in that time. When the shutter speed is decreased, the shutter remains open for a longer time, allowing light to fall on the sensor for a longer time. Hence the trailing path of light is seen. When it is increased, we see fast objects very clearly. This is commonly used in sports photos.


Other topics will be covered in future posts.

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