What is Aperture? What is Shutter Speed? What is ISO? What is White Balance? What is Depth of Field?

6 Answers

  • Sky
    Lv 7
    2 months ago
    Favorite Answer

    There are a LOT of photography channels on youtube that can give you detailed explanations of each of those.  Here's a quick rundown.

    Aperture:  the opening in the lens that light passes through, and it is adjustable to allow more or less light through to the camera as needed.

    Shutter speed:  how much time the camera's sensor or film is allowed to gather light.  The shutter is a pair of flaps that quickly open and close in front of the sensor/film, remaining open for the length of time determined by the shutter speed setting.

    ISO:  how sensitive the camera's image sensor or film is to light.  Film comes in different ISO sensitivities and typically can't be changed until the film is used up and a new roll of film is inserted with a different ISO.  Digital cameras can change the ISO sensitivity of the sensor either automatically or manually, as needed for the correct exposure.

    White balance:  what color of light the camera is expecting there to be in order to adjust itself so that white objects actually look white (or some shade of pure gray).  Direct sunlight, clouds, light from a clear sky while in shade, a camera flash, and different types of light bulbs all have different light colors and therefore all have a different white balance.

    Depth of field:  how much of the scene is in focus.  With a shallow depth of field, only the subject may be in focus while everything closer to and farther from the camera is out of focus and blurry; with a long depth of field, a lot more of the scene can be in focus, and with some settings everything will be in focus.  Depth of field is directly affected by aperture:  a wide open aperture lets through a lot of light but has a very shallow depth of field, while a very narrow aperture lets through far less light and requires a longer exposure time (slower shutter speed) but most or all of the scene will be in focus.

    Here are some youtube channels I recommend for lots of instructional photography videos:

    • AdoramaTV (many different pro photographer presenters)

    • Jared Polin/Fro Knows Photo (particularly his older videos, as newer ones focus more on camera and lens reviews)

    • Imre Z. Balint (he hasn't made videos in years but what he did make are informative and easy to understand)

    • Gavin Hoey (one of the AdoramaTV presenters, his own channel)

    • Karl Taylor (everything from beginner to advanced studio work)

    • Thomas Heaton (landscape and travel photography)

    • Tony & Chelsea Northrup (everything from beginner to advanced)

    • SLR Lounge

  • John P
    Lv 7
    2 months ago

    They are fundamentals in photography. A suitable combination of all those factors will help you get technically good photos.  Most cameras sold in recent times automatically give you a lot of help with those matters.

    Then all that is left for you exercise is your pictorial judgement.

  • Anonymous
    2 months ago

    Aperture = how much light is allowed the reach the camera by the lens

    Shutter speed = how fast the shutter is moving when the picture is taken. The faster the shutter speed, the shorter the duration of light exposure to the film or sensor

    ISO = how light sensitive the film or sensor is

    white balance = how red or blue the camera assumes the incoming light is. If there is a lot of red light, the camera's film or image processor may reduce the amount of red color in the final image.It depends on what type of film is used or on what the user setting is on a digital camera.

    Depth of field = how much distance is it between the farthest and closet reasonably sharp objects in the picture. It can be as shallow as a few inches or less or as deep as thousands of feet or more.

  • qrk
    Lv 7
    2 months ago


    Look through the Photo Essentials section.

    If you want to get in to the nitty  gritty bits of depth of field:


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  • Sumi
    Lv 7
    2 months ago

    Do yourself a huge favor and get one of these books:

    Brian Peterson's "Understanding Exposure."

    Tony Northrup's "Stunning Digital Photography."

    These books will go into far more detail with example to make the concept much more clear than anyone can here in this forum.

    Also, go to YouTube and do a keyword search for any term you're confused or simply curious about.

    In a nutshell, here's my answer to your question:

    Depth of field (DOF):  This is simply the area in any image that appears to be in focus.  It is chiefly controlled by the aperture.  A small aperture (large f/ number) will produce more DOF, while a large aperture (small f/ number) will produce a shallower DOF.

    Aperture: this is the opening in the lens.  It control the DOF and the intensity of light entering the camera so that the photographer can then use a faster or slower shutter speed.

    Shutter Speed:  The time the light is actually striking the film or sensor.  A faster shutter speed will freeze action but will require a larger aperture and/or higher ISO.  A slower shutter speed is used either because the photographer needs to use a small aperture for increased DOF, or for intentionally blurring motion such as clouds, water and people.  The intentional blurring of moving subjects is done to evoke a feeling of motion in the image.

    White Balance: This is how the camera adjusts for color temperature (in Kelvin) of the light.  Color temp of light simply describes the color given off by the light.  For example, traditional incandescent lights give off a red/orange color, fluorescent lights give off green light, and sunlight at noon is roughly white light although the color temp of sunlight changes as the Sun gets lower in the horizon.

    Cameras will all have an auto white balance setting.  Many have presets for incandescent, fluorescent, daylight and flash (which is blueish). Why do you need to make this setting?  Well, the camera uses the setting to know how much and what kind of color correction to make so that the fluorescent image isn't green, the incandescent isn't red/orange and remove the blueish tinge from flash photos.  If you were to set any camera's WB setting from AUTO to Daylight and shoot under incandescent light, the resulting images would be very, very red/orange, and under fluorescent light, the images would be very green.  Now, if you shoot RAW, this would not be a problem because you can adjust the color in RAW images without any restrictions.  However this IS NOT the case with JPEGs.  Unlike RAW files which use separate computational variables for the light and the color, JPEGs use only only one.  This means that if you do not get the WB right you will never be able to remove the color cast from the image - i.e. your image is f...ked.

    For the most part auto white balance (AWB) is good enough for even those shooting JPEGs.  The only time you'd use a manual setting or a preset is ensure consistent color balance among all of the shots which makes doing a batch color correction infinity faster than having to go in and change each image.  Of course, this is a situation not often experienced by the average Joe consumer.

  • Alan
    Lv 6
    2 months ago

    What is shutter speed?

    The camera is a light tight box that encloses a special electronic chip with light-sensitive surface that in modern times replaces photographic film. Both these surfaces are super sensitive to light -- thus the camera body shields these surfaces from accidental exposure to light. The front of the camera contains a lens that can project an image of the outside world onto the light-sensitive surface, now called an imaging chip. To prevent accidental exposure, the image that the lens can present to the imaging chip is blocked from entry into the camera. This blockage device is called a shutter. When we are ready to take a picture, we press a button called a shutter release. This activates the shutter mechanism; it opens briefly ,and this allows the image produced by the lens to play on the surface of the imaging chip. After a time, the shutter closes, and the resulting image is recorded as an electrical signal. Computer-like software in the camera converts this image into a digital file and stores it for future display on a TV or computer screen. The amount of time the shutter is allowed to be open is called the shutter speed. Usually the time the shutter is open is super short like 1/100 of a second. The photographer and/ or the camera software will adjust the shutter speed for conditions. A picture taken of a sporting event generally requires a fast shutter speed, as does a humming bird in flight. Dim scenes, like a candle lit dining room, require a far longer shutter speed.

    What is aperture? The camera lens is the window to the outside world when it comes to picture taking with the camera. Generally the camera lens has a diameter defined by a circular opening called the iris. This name comes from the opening that lets light into the human eye. Another name for this opening is aperture. Modern camera lenses likely allow too much light to play on the imaging chip. Thus it is necessary to reduce the light-gathering ability of the lens by making the aperture diameter smaller. Actually, the aperture diameter of a modern camera lens is highly adjustable as to its working diameter. These adjustments allow the camera to take pictures under super bright conditions such as a sunlit beach (small working diameter) or a picture inside a coal mine, super dim conditions which require a large diameter aperture opening.

    What is ISO? Photo film or the digital sensing chip is made sensitive to light. Under dim lighting conditions, we need an imaging surface that will work in feeble light. To accomplish we need a highly sensitive surface. Conversely, when taking pictures at the beach under bright sun, we need to turn down the sensitivity of the imaging chip. Chip sensitivity is stated as a numerical value. The question becomes, how is the sensitivity of the imaging chip calibrated? An international committee based in Switzerland has been designated as the calibrators of film and imaging chips. They write the rules that measure this sensitivity. This group of scientists is called the International Standards Origination -- or more simply ISO.

    What is White Balance? As you know, sunlight varies in color throughout the day. In the morning and evening sunlight is quire ruddy. At noon sunlight contains more a more blueish light. Artificial light can present rather different colors of light. The camera software must sort this out and adjust the image so that it appears “normal” as to say the color of human skin or other objects. This software task is called white balance. It can be an automatic function of the camera. Under conditions of unusual lighting or when high precision images are required, we can manually override white balance software using a reference placard, usually a white card or perhaps a gray card. For the average person, the camera will automatically white balance and the image produced will be satisfactory.

    What is Depth-of-field? The camera lens is adjusted to obtain a sharp and clear picture by mechanically moving it closer or further from the imaging chip. This needed distance is a function of subject distance from the camera. We focus on an object that is at a specific distance, and it will be rendered tack sharp. Additionally there is a span of distance before and behind this principal focus point that will image as acceptable as to sharpness. This is the zone we call depth-of-field. This span can be expanded or contracted based on the working aperture diameter and subject distance. Skilled photographers become adept at making changes to the camera optics to achieve the span of depth-of-field that enhances.

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