Difference between revisions of "Camera Fundamentals"
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Simply put, ISO is the sensitivity of the material that produces the image. For digital cameras, it is a fancy senser, and analog cameras use sensitive film strips. It seems odd, but both describe their sensitivity as ISO. The ISO can be 100, 200, 400, 800, 1600, 3200 etc, with higher ISO being more sensitive. The higher the ISO, the more the sensor or film it is affected by the light from the scene, and will show the scene as a brighter image. Increasing the ISO has a drawback, it adds visual noise. For film, this is called grain and for digital it is seen as little errors in the pixels where the colors are adding randomness. For this reason you usually want to prioritize using lower ISO while balancing the overall exposure with the aperture and the shutter speed. | Simply put, ISO is the sensitivity of the material that produces the image. For digital cameras, it is a fancy senser, and analog cameras use sensitive film strips. It seems odd, but both describe their sensitivity as ISO. The ISO can be 100, 200, 400, 800, 1600, 3200 etc, with higher ISO being more sensitive. The higher the ISO, the more the sensor or film it is affected by the light from the scene, and will show the scene as a brighter image. Increasing the ISO has a drawback, it adds visual noise. For film, this is called grain and for digital it is seen as little errors in the pixels where the colors are adding randomness. For this reason you usually want to prioritize using lower ISO while balancing the overall exposure with the aperture and the shutter speed. | ||
− | [[File:ISO.png|centre|frameless|alt=Graphic displaying exposure qualities of ISO. Original work by Caelin Eddy.|ISO allows more sensitive sensors to let the available light to be shown as brighter, but results in a "noisy" image.]]<gallery> | + | [[File:ISO.png|centre|frameless|alt=Graphic displaying exposure qualities of ISO. Original work by Caelin Eddy.|ISO allows more sensitive sensors to let the available light to be shown as brighter, but results in a "noisy" image.]] |
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+ | File:F-22.jpg|Item 1 | ||
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Revision as of 11:50, 23 August 2020
Page in progress
Cameras at Evergreen: Most academic projects can benefit from a camera's ability to create images and videos, like for presentations, event promotion, project documentation. This page outlines basic camera information and the resources at Evergreen to help you complete your camera related projects. For beginners as well as advanced users, Media Loan top camera reccomendation is the Canon Rebel, like the T6i model. You can pick up cameras and their accessories at Media Loan then edit or develop your media at Photoland or the Multimedia Lab (MML). See Media Loans Policies for more information on how to checkout gear and other resources.
Page Overview: This page covers the basic topics for getting started with cameras. The infomation covered will provide the foundation to taking good pictures and videos. The controls and buttons of a camera can be dauntings, but this guide will point out the key features to get started for your project. The guide will aslo point out the most relevant campus resources to each topic.
Contents
Exposure
Exposure is the most important takeaway from this article. If an image is overexposed it will be blown out and look too white, on the other hand, an underexposed image is too dark. Getting the correct exposure is a balancing act between three controls and each one has a side-effect. These controls are called ISO, aperture, and shutter speed. Photos can look wildly different based on how you adjust these controls. Most phone cameras handle these exposure controls automatically, and other cameras can do that to. However, understanding the controls can allow you to take the exact pictures you want, like taking pictures in low light, having everything is focus, or having no motion blur. If you prefer videos, here are a couple on these exposure topics; ISO, aperture and shutter speed. To play with a simulation of exposure controls, check out an Exposure Simulator by Anderson Images or an Exposure Simulator by Canon.
ISO
Simply put, ISO is the sensitivity of the material that produces the image. For digital cameras, it is a fancy senser, and analog cameras use sensitive film strips. It seems odd, but both describe their sensitivity as ISO. The ISO can be 100, 200, 400, 800, 1600, 3200 etc, with higher ISO being more sensitive. The higher the ISO, the more the sensor or film it is affected by the light from the scene, and will show the scene as a brighter image. Increasing the ISO has a drawback, it adds visual noise. For film, this is called grain and for digital it is seen as little errors in the pixels where the colors are adding randomness. For this reason you usually want to prioritize using lower ISO while balancing the overall exposure with the aperture and the shutter speed.
Aperture
Aperture controls how much light is let through the lens. Aperture is the hole that light is let though and the mechanism that widens and narrows that hole is called the iris. Our eyes also have an iris that automatically changes our eyes' aperture, AKA pupil, in response to how much light we see. It is intuitive that a larger hole lets in more light, increasing the exposure. The numbers however are not intuitive and get smaller as the hole is bigger. The aperture is measured in F-stops written like this; f/1.4, f/2, f/2.8, f/4 etc. The lower numbers can be described as more opened or large, whereas a higher number can be described as more closed or small. Some people describe a smaller aperture as a fast lens, but this language isn't the clearest. We need to talk about focus in order to understand what aperture does. The focus of an image is a plane parallel to the lens where it is when the clearest, you usually want this to be on the most important part of the image like someone's face. What is out of the focus is seen as blurry. The focus can be moved forward and backward, but more on that in the Lens section below. For now, let think about how the focus has a width, this is called the “depth of field”. A wider depth of field allows more parts of the image to be clearer if they are within the focus. The depth of field is controlled by the aperture. It is again counterintuitive that the smaller hole (higher number) is actually a wider depth of field. On the other end, a bigger hole (lower number) is a narrow depth of field. For example you may want just your picture of a flower to have the flower in focus only and the rest blurry so you would want a higher aperture. This also then means that your photo is getting less exposure, so you would need to adjust your other controls like ISO might need to be brought up to increase your overall exposure. There is also an the same material.
Shutter Speed
The last control we have over the exposure is the shutter speed. The shutter is a door that opens to let light in so it can go on the sensitive material that makes the image. The time that it is open is the shutter speed. It is measured in units like 1/60 seconds, 1/125 seconds, 1/250 seconds, 1/500 seconds. These numbers are often shortened to just the number at the bottom of the fraction. So in that way, where 1/60 seconds is just 60, the bigger numbers would be quicker shutter speeds. A longer shutter speed would allow more light in, increasing the exposure, but not capturing movement clearly. While the shutter is open, any movement in the scene going into the camera would be captured as a blur, while quicker shutter speeds would just capture a moment of the movement rather than a blurring the change of the scene over time. This blurring is called motion blur. Sport and wildlife photography usually calls for clear, unblurry images of movement, so they need to have quick shutter speeds, meaning the ISO and aperture would need to be adjusted to allow for more exposure to compensate for the quick shutter speeds lack of exposure. Again, there is a video covering the asme material
Balancing Exposure
Setting the correct exposure for your photo can enable you to have control over if your image has Noise from the ISO, depth of field from aperture and motion blur from shutter speed. For analog there is little automatic function, so you will need to manually choose all of your settings. For most digital cameras, they have a dial on the top right that you use to choose from Modes like P, A, S, M, Auto, Video, ect. This is called the mode dial and can be used to choose if it's in full automatic, aperture priority where you choose aperture and it chooses the other exposure settings. For more on this, look at the mode dial section of the Canon Rebels Operating Guide.
Exposure Element | Other/Related Names | Exposure Method | Effect | Unit | Higher number means... |
---|---|---|---|---|---|
ISO | Film Speed | Sensitivity of Image Material | Grain for Analog, Pixel Noise for Digital | ISO of 400 | More exposure, more noise |
Aperture | Iris | Size of opening | Depth of field | f-stop of f/2.8 | More exposure, less Depth of field, |
Shutter Speed | Shutter | Time of exposure | Motion Blur | Shutter of 250 (which refers to 1/125 of a second) | Less exposure, less blur |
Lens
Lenses are used to control focus and focal length. Different cameras have different mounts and Media Loan has a range of lenses for each camera mount type.
Focal length
Focal length is the distance from the lens to the sensitive material. This is measured in millimeters and lenses are often defined by their focal length like 55mm, 100mm 150mm. Focal lengths affect “angle of view”, which is the angle produced by the lens. This angle is dependent on the focal length. The shorter the focal length, the wider the angle of view, which looks like it sees closer and more width. The longer the focal length the narrower the angle of view, which looks farther and narrower. Fish eye is a very wide angle of view because it has a short focal length, and a Telephoto is a very narrow angle of view because of its long focal length. Some cameras have fixed focal lengths; these are called prime, but most have variable focal lengths called zoom. Zoom lenses are shown by a range of numbers like 25-200mm. For a video on these concepts check out this Focal Length video.
Fish-eye | Wide-Angle | Standard | Telephoto |
---|---|---|---|
<24mm | <35mm | 35mm to 70mm | >70mm |
cine?
Macro?
To play with simulations of different types of lense check out the Nikon Lens Simulator.
Analog & Digital
Analog Cameras
The main different categories of analog cameras are based on the size of film it uses. The smallest is 35mm, while the others are simply called medium format and large format: 35mm in this case refers to the film size and not the focal length. The medium and large format use bigger film sizes, so that images can have incredible resolution. This detail means that the image can be scaled up for large prints. Large format cameras tend to have bellows that look like an accordian. Although these cameras are of an older design, they are still used by professional photographers today. You will most likely want to use a light meter to help get your meter, so check out this light meter guide. Media Loan offers all of these types of cameras, but the best to start with is a 35mm called the K1000. A proficiency test is required to use this camera, all info is in this 35mm operating guide.
Film: There is black and White film and color. Both use the ISO rating described in the exposure section above. You can buy many types of film at a media loan. Photoland at the bottom of the library has a Black and White darkroom to develop your own photos and Media Loan offers a paid service to develop color film.
Digital Cameras
Digital Cameras have many automatic features available. Automatic exposures, focus, and white balance can be used to make taking pictures quickly easy. These tools although they enable speed, they can limit your artistic expression. There are many kinds for Digital Cameras. The most common are the DSLR, camcorder, and action cameras like the GoPro. DSLR stands for Digital Single Lens Reflex. Media Loans best DSLR for starting out is the rebel T6i. To take a proficiency test to use this Camera, read through the Canon Rebel Operating Guide.] There is also the Go pro.
Putting on a Computer: Image files live on SD cards or internal memory. You can either take the SD card and use a card reader either in the Multimedia Lab or check one out to Media Loan. Most also have a USB connection on the side. You can just connect a computer to directly using a usb cable. When on the computer, just be sure to drag the files or folder onto your computer to copy them. You can see the photos on the SD card, but they wont live on the computer until you copy it or import it to the computer. Other programs may import and store it for you like "Photos" on apple products, in which case you would need to follow the prompts. Sometimes you need to turn the camera on after plugging it into the computer if you are using the USB connection. You can either format the SD card from within the camera's settings to delete all the files on the SD card or you can delete it from the computer to achieve the same effect.
Photography
There are a number of different concepts and attachments that only apply to photography and not video. Bulb mode for instance is when you set your shutter speed so slow that the camera allows you to hold the shutter button (for taking a picture) and just hold it for how long you want the shutter to stay open. You can also can pictures for stop motion, these pictures can be compiled into a gif or video. You can also make profesional panoramas, or 360 images using a gigapan panoramic tool for a camera. For all of these projects you will need a photo tripod.
There are many additional attachments to add onto panorama. You may also want to use attachments that trigger the camera remotely using a small connector. This can help to not bump the camera when taking a picture. For flash, you can use the flash on the camera itself, add on an external flash that attaches to a thing called a hot shoe. The Hot shoe tells the external flash when the camera is taking a picture and tells it when to flash the lights. There are also studio lights like those that can send a wireless signal to lights on stands to flash when a remote attached to the hot shoe goes off. For that equipment, check out the https://helpwiki.evergreen.edu/wiki/index.php/Elinchrom_Studio_Flash_Kit_Operating_Guide Elinchrom Operating Guide.] For indoor shoots, you can use a backdrop to help manage light and set a good background. For film development, all the information is listed in the above film section. But, for digital photography you can use the Digital Imaging Studio (DIS) for using programs like photoshop and printing your photos using high quality and large printers.
Video
Video is just a camera taking pictures at a quick speed and played back in the same order. The same exposure and lense qualities still apply to recording video. Because of the dynamic nature of shooting video, you may want to rely on some of the automatic features of digital cameras. Although Medialaan does have vintage Analog video cameras, they are very limited access, so all considerations for video in this section will be about digital cameras. There are tons of options when it comes to video making. The Canon Rebels, Vixias and GoPro are good options. You can go handheld, or put in on a stabilizer, to make smoother shots. You can use a tripod, gorillapod (for lower shots), monopod (for light weight productions) or a unique mount called the pocket skater. The pocket skater is a small adjustable mount with wheels. You can change the wheel direction or camera angle and lock it to make smooth curved track movements for indoor use and flat surfaces. All of these digital cameras have their own microphones built into the cameras. You could just use this built in camera, but most of the time, you will benefit from adding a bit of gear. Most cameras have an external input as an ⅛” input (AKA mini, aux, 3.5mm) that some microphones can connect to. The mics can mount to the top like the rode, or they can be clipped to a performers collar. For better audio, you may want to use a seperate piece of equipment called a field recorder. Not only do they have better recording quality, but they connect to higher quality cameras. For more information on audio check out the [link doesn't exist yet Audio fundamentals pages] field recorder section. Once you have gathered all your shots, you will likely want to edit your video in the Multimedia Lab (MML). The best choice for editing video is with Adobe Premiere, and then to add graphics and effects use Adobe after effect. You can edit the audio of the video within premier, but for finer touches, you may also want to use Adobe Audition.
Lighting
Check the link to the [ Lighting Wiki Guide] for information on how to effectively light a scene or subject. Media loan has many lighting kits for both LED and hot lights.
Continue
To continue your skills with cameras, learn different cameras operating guides to take proficiency tests so you can use them. You can also take classes on cameras for photography or video or just media in general. For those classes look in the Media pathways or moving images area. Advance gear in media loans Advanced Production Service (APS) is available for people in specific media classes