📷Photography📷

                             Photography

The art or process of producing images by the action of radiant energy and especially light on a sensitive surface (such as film or an optical sensor).    

    

       Composition Methods: 

                            Rule of Thirds

                                 Golden Ratio

                              Leading Lines

     

       Pillars of Photography:

                                                  Shutter Speed

                                                  Aperture

                                                  ISO



 Shutter Speed:
                          Shutter speed is responsible for two things:changing the brightness of your photo and creating dramatic effects by either freezing actions or blurring motions.The amount of time the shutter takes to close after opening,to allow light to be gathered by the sensor for an exposure.There are two types of shutter speed-"high shutter speed and low shutter speed".Longer exposures are called low shutter speeds and vice versa.High shutter speed values are 1/500,1/8000,1/200 etc.Low shutter speed values are 1/15,1/30,1/8 etc.Low shutter speeds are also used to photograph objects at night or in a dim environment with a tripod.           

          

 

 What is a camera shutter?
                                               When the camera fires, the shutter opens and fully exposes the camera sensor to the light that has passed through your lens. After the sensor is done collecting the light, the shutter closes immediately, stopping the light from hitting the sensor.


  Aperture:
                  Aperture is a opening within a lens, through which light travels into the camera body. You can shrink or enlarge the size of the aperture to allow more or less light to reach your camera sensor.Aperture has several effects on your photographs. One of the most important is the brightness, or exposure, of your images.

                                                                        
    Types of Aperture:Small aperture and Large aperture
                                Small        →        →         Large

Small aperture lets more light and large aperture lets less light. 


                             Depth of field

In optics, particularly as it relates to film and photography, the optical phenomenon known as depth of field, is the distance about the plane of focus where objects appear acceptably sharp in an image.


Shallow depth of field:
                                      Some images have a “thin” or “shallow” depth of field, where the background is completely out of focus.Small aperture,only one object focused and more light let in.


Deep depth of field:
                                 Other images have a “large” or “deep” depth of field, where both the foreground and background are sharp.Everything will be focused,large aperture and less light let in.

                          

   

ISO:

International Standard Organisation.

Used when there is low light. 

It produces an artificial light.

Last priority should be given to it.

When it is high,digital noise are formed in the picture.             

    

White Balance

 White balance (White Balance) is the process of removing unrealistic color casts, so that objects which appear white in person are rendered white in your photo. Proper camera white balance has to take into account the "color temperature" of a light source, which refers to the relative warmth or coolness of white light. Our eyes are very good at judging what is white under different light sources, but digital cameras often have great difficulty with auto white balance (Auto White Balance) — and can create unsightly blue, orange, or even green color casts. Understanding digital white balance can help you avoid these color casts, thereby improving your photos under a wider range of lighting conditions.


Exposure:

                In the simplest of terms, exposure for photographers refers to how an image is recorded by camera sensor and how much light is captured. Basically, it determines what the image you capture will look like.To achieve the right exposure, you need to consider three things: ISO, Aperture settings and the Shutter Speed.

Stops:
           Used to change exposure.


  Increasing or Decreasing stops using shutter speed:

Double the shutter speed to increase one stop.
Ex:1/60→1/120
Decrease the half of the shutter speed to decrease one stop.
Ex:1/200→1/100.                                                                    
                           

 Increasing or Decreasing stops using aperture:

decrease the aperture values to increase stop or divide it by 2.
Ex:F5.6→F2.8,stop increase.
Increase the aperture value to decrease stop or multiply it by 2.
Ex:F2.8→F5.6,stop decrease.
                         

  Increasing or decreasing stops using ISO:

ISO increases, one stop increases(*2).
Ex:100→200.
ISO decreases,one stop decreases(%2).
Ex:200→100.            


                                    Metering Mode
Metering is how your camera determines what the correct shutter speed and aperture should be, depending on the amount of light that goes into the camera and the ISO.

Matrix / Evaluative Metering:

                                                                                                   In this metering mode, the meter divides the scene up into a grid and analyzes each segment for highlight and shadow (bright and dark) information.Once that data is collected, it calculates the average value and bases the exposure on that average.

Center-Weighted Metering:

                                             This method of metering lays the most importance on the central portion of the frame, which can be as much as 75% or more, while little or no importance is given to the corners of the frame.Many pro DSLR’s will allow you to adjust the diameter of the center weight area.

Spot Metering:

                         This mode measures the light from a very small part of the scene only.  The area measured is typically the center of the image, using approximately a 3 to 7 degree range of measurement.  It is usually less than 5% of the area of the frame. With most of the mid to upper end DSLR’s,you can arrange the placement of the spot within the frame so as to identify where you want the reading captured (usually it follows where you focus).

Partial Metering:

                                          Partial Metering is similar to Spot Metering, except the covered area is larger (approximately 8% of the viewfinder area near the center vs 3.5% in Spot Metering). 

                                                             
                                                         Exposure Compensation

• Ansel Adam(1902-1984) says that,camera will convert white,black or any color to 18% grey.
• We could change it to exact white or black color using exposure compensation.

AV,TV and P are also the modes which we could change the exposure compensation.



                                                               Histogram
A graphical representation of the tonal values of your image.In other words,it shows the amount of tones of particular brightness found in your photograph ranging from black (0% brightness) to white (100% brightness).

Underexposure

 

Overexposure

Correct exposure

                                                                             Raw
RAW is a file format that captures all image data recorded by the sensor when you take a photo.When shooting in a format like JPEG image information is compressed and lost. Because no information is compressed with RAW you’re able to produce higher quality images, as well as correct problem images that would be unrecoverable if shot in the JPEG format.

Raw→professional shooting
Jpeg→casual photography

ADVANTAGE:

• Can recover back to normal form.
• Gives original true tone colors     

                     
DISADVANTAGE:

• Larger file size.
• Faster card needed to read the image[takes time to save and read the image in the card].    

                                                      Lighting Technique


       The Standard 3-Point Lighting Technique

• The Three Point Lighting Technique is a standard method used in visual media such as video, film, still photography and computer-generated imagery. It is a simple but versatile system which forms the basis of most lighting.
• The technique uses three lights called the Key light, fill light and back light.

Key Light
                This is the main light. It is usually the strongest and has the most influence on the look of the scene. It is placed to one side of the camera/subject so that this side is well lit and the other side has some shadow.

Fill Light
                      This is the secondary light and is placed on the opposite side of the key light. It is used to fill the shadows created by the key. The fill will usually be softer and less bright than the key. To achieve this, you could move the light further away or use some spun. You might also want to set the fill light to more of a flood than the key.

Back Light
                  The back light is placed behind the subject and lights it from the rear. Rather than providing direct lighting (like the key and fill), its purpose is to provide definition and subtle highlights around the subject's outlines. This helps separate the subject from the background and provide a three-dimensional look.

Beauty Dish
                    A beauty dish is a photographic lighting device that uses a parabolic reflector to distribute light towards a focal point. The light created is between that of a direct flash and a soft box, giving the image a wrapped, contrasted look, which adds a more dramatic effect and used for model photography.

Snoot
          It is used for product photography.It sharpens the edges of the product.

          
Board reflectors

                           Also known as plane reflectors, "flats" or bounce boards, this kind of reflector is located independent of a light source; the light is reflected off its surface, either to achieve a broader light source, or control shadows and highlights, or both. This kind of reflector generally has a very low reflectivity factor that varies widely according to surface texture and color. As a result, it is most commonly used to control contrast in both artificial and natural lighting.