In case you were curious about DSLR cameras
For my internship this summer they asked me if I had any experience with a DSLR camera. My dad has always taken tons of photos, and before the iPhone was a thing he used to have point and shoot. It was never as fancy as a DSLR though, so I figured I should do a bit of research. I mean why not understand a bit more about how cameras work right?
Basically what I gathered is it’s important to understand a few things about your DSLR (which stands for digital single-lens reflex camera by the way) before you get started.
Some basics of the DSLR:
Shooting modes are found on the labeled dial on the camera
Auto = aperture and shutter speed are set by the camera for you
A = aperture priority, or the size of the opening of the lens to determine how much light is let through
S = shutter priority, this is a speed measured in fractions of a second and determines how long the shutter stays open when a photo is being taken
P = program, allowing you to set the aperture OR shutter speed and the camera will automatically adjust the other in response
M = manual, set aperture and shutter speed all yourself
Macro / The Flower Icon = for super close-up shots, reducing the focus time for these shots
Portrait / Person Icon = for portraits of people, if enabled it’s capable of face detection, automatic red-eye reduction, and especially useful if special make-up products are being used on the face
Landscape / Nature Icon = adjusts settings automatically for taking nice photos of nature and landscapes… entails using a small aperture to gain depth of field for the captured scene
Action / Running Person Icon = increases ISO and uses a faster shutter speed to catch quality action shots
ISO (International Organisation of Standard):
ISO determines how sensitive the camera sensor is to light. In general it is important to know that a lower iso will correlate with a brighter crisper image with less grain.
The Exposure Triangle relates aperture, shutter speed, and iso together. Adjusting one impacts all of them and you need to know how to compensate to make sure photographs turn out well.
Metering is also an important concept related to the exposure of an image. The camera calculates an average exposure across the light & dark parts of the captured scene, then tones the entire image to an average called the middle grey
Average = image is assessed corner to corner and exposed to 18% grey
Centre-weighted = the exposure is weighted for the centre of the viewfinder, meaning about 80% of image, and ignores the corners
Spot metering = camera uses a small circle in the centre that is only about 5% of the whole image to read and exposes the whole scene to 18% grey from that assessment
Exposure Compensation is the act of increasing or decreasing the default exposure meter reading to correct image
Focus means the subject of the image is NOT blurry
Autofocus setting on a camera has 2 different options
AF-S is for stationary objects, you half press the button and then focus is acquired and locked while button held
AF-C is for moving subjects, and once the button is half pressed it refocuses on particular subject automatically until the photo is taken
File Size & Type is a huge field but important to understand the basics. The largest/finest/super fine file sizes and types make the most of megapixels.
Usually images shot with a DSLR are either
RAW = uncompressed, containing lots of image data, but also taking up lots of space
JPEG = automatically processed by camera and compressed, take up less space in memory
Finally, relating to colour tone of an image, white balance is important. This is because different light sources emit different wavelengths of light, therefore they result in different colours – or different temperatures of colour.
Our brains recognise that these colours are reflected off surfaces and counters the effect so that whites stay white, but cameras are unfortunately not that smart and don’t automatically correct tone.
That’s why we have colour presets (the name of each setting basically denotes when it should be used):
Daylight = bright, sunny, clear, neutral
Cloudy = adds warmth to daylight images
Tungsten = to be used when shooting indoors under incandescent bulbs or street lights because it cools the yellow tones
Fluorescent = compensates for green/blue of indoor light strips
Flash = adds cool blue cast to add some warmth
So that was a brief crash course, or more like an explanation of some of the settings on a DSLR camera.
But honestly, while I was doing all of this what I kept thinking was how the heck does a camera even work? Like I get it’s something to do with light, but really, isn’t it crazy that this piece of electronics and really our smart phones have gotten so good at it these days, and when we take pictures we hardly give it a second thought. But HOW does it work??
So I did a bit more research. Read on if you want :)
The way cameras work:
Optical lens + Chemical film + Mechanical camera design
Apparently a camera is able to take all the light rays bouncing around (which our eyes also use to see what we see on the daily) and redirects these rays to a single point to create a “sharp image”.
When I first read that on google I was confused. Online resource convinced me that there are 6 fundamental aspects to photography, or at least 6 things that are really important if you’re trying to take a picture that will work at all.
Light (hard / soft, natural / unnatural, classified based on the strength and density of the shadows it produces… soft light produces soft shadows, where as hard light produces hard, dark shadows)
Subject is more obvious: who and what you’re taking photos of, and this is important based on how you plan to compose the image and balance it
Optics / Lenses are used to focus the light and capture the image onto a recorded medium. They control the focal length of an image, the angle of view, magnification and help describe it.
Aperture controls the amount of light let into the photo before it hits the sensor, thus also controls the depth of field of the image, where depth of field is basically how sharp the sides and background of images are as you move away from the focal point
Time / Shutter Speed is mentioned above, but is really important to control. If it’s faster then there is less light let in and movement is frozen more easily so you can capture motion. Slower shutter speeds let more light get in and so motion is blurred.
Medium is what the image is actually recorded on to once light passes through the lens.
Remember that a lens is just a curved piece of glass or plastic with the job of taking light beams that bounce off of an object and slowing them down before redirecting them so they come together to form a real image of what is right in front of the lens.
The chemical component in a traditional camera is film. Essentially, when you expose film to a real image, it makes a chemical record of the pattern of light. It does this with a collection of tiny light-sensitive grains, spread out in a chemical suspension on a strip of plastic. When exposed to light, the grains undergo a chemical reaction.
But what about on our smartphones where we don’t go anywhere near film developers anymore? Inside the camera of our iPhones, there's an image sensor. This is equivalent to the retina in our eyes. The image sensor converts light or photons into an electrical signal.
The sensor consists of a bunch of pixel sensors. As photons hit the photodiode of the pixel sensor, they slowly build up a charge. These charges change depending on the number of photons and the intensity of the light.
For our phone, we want this array of a bunch of charges to be turned into voltages. Once all these voltage levels are generated, they are passed on to a digital image processor. That’s about as much of an overview as I can give without my brain exploding.
Basically these days it all has to do with light intensity and photons and charge and pixels as opposed to the good old days when you basically reflected some light onto some film and got it developed later on.
I guess all that matters now is you look cute for the photos that can be composed, captured, and viewed instantaneously… right?
