Digital Photography. Digital Cameras and Digital Photography. Your camera. Topics Your Camera Exposure Shutter speed and f-stop Image Size Editing

Transcription

1 Digital Cameras and Digital Photography Topics Your Camera Exposure Shutter speed and f-stop Image Size Editing Faculty Innovating with Technology Program Aug 15, 2006 Digital Photography Your camera Virtually all digital cameras an optical or electronic viewfinder, a color LCD display panel for previewing an image and showing menus, a shutter release, and a clutch of control buttons. Most also have one or more slots for removable storage, such as Secure Digital or CompactFlash cards, a builtin electronic flash unit and a serial or USB port for connecting the camera to your computer when you want to download photos. Page 1

2 Common Camera Controls Locate on your own cameras 1. An LCD viewfinder helps you compose your photos. 2. Removable flash memory enables you to shoot more photos. 3. The mode control dial helps you select the right shooting mode for the conditions. 4. Exposure detail in the LCD display shows you the shooting mode and whether you need to use a flash. Page 2

3 Locate on your own cameras 5. This camera has a built-in microphone for recording sound in movie mode. 6. Along with internal memory, the camera has a MultiMediaCard (MMC) or Secure Digital (SD) flash memory slot. 7. The docking port enables the camera to connect to Kodak camera and printer docks. 8. The camera can use alkaline, Ni-MH, or lithium AA or battery packs for power. Camera Controls Locate on your own cameras Page 3

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5 Locate on your own cameras Page 5

6 Digital Camera Storage Media All except the very cheapest digital cameras use removable storage. Here are examples of several types. Page 6

7 Digital Photography Exposure: Shutter speed, Aperture (f-stop) and EV Shutter Speed Slow shutter speeds allow more light to reach the sensor Motion may be blurred Higher-end cameras may have imagestabilization Compensate for hand movement when shutter is open Page 7

8 Using Shutter Priority Mode You choose the shutter speed you'd like to use, and the camera's metering system selects the appropriate f-stop. Perhaps you're shooting action photos and you want to use the absolute fastest shutter speed available with your camera Or, you might want to use a slow shutter speed to add some blur to an otherwise static photograph. Fast Shutter Speed Example Fast Shutter Speed Example Page 8

9 Slow Shutter Speed Example Aperture (F-stop) Lens Aperture The lens aperture is the size of the opening that admits light to the sensor A wider aperture lets in more light, allowing you to take pictures in dimmer light. Aperture size is adjusted by f-stops f-stops numbers are actually the denominators of fractions an f2 opening is larger than an f4 opening, which is in turn larger than an f8 aperture. Using Aperture Priority Aperture priority will automatically set the shutter speed based upon the aperture you choose Using the smallest f-stop possible will maximize depth-of-field in a close-up picture. Use a large f-stop to throw everything except your main subject out of focus Page 9

10 Small aperture example Large aperture example Optical vs. Digital Zoom Optical zoom the relationships of the individual elements of the lens are changed to produce the changes in magnification. Digital zoom the apparent magnification is actually produced by simply enlarging part of the center of the image Advantage of optical zoom - Because the lens elements can be fine-tuned, this produces the sharpest image at each lens magnification Page 10

11 Simple Lighting Adjustments with EV EV compensates for a light subject against a dark background or a dark subject against a light background. EV provides up to two values more or less exposure than the camera would normally provide Each positive EV value is the same as opening up the lens an additional f-stop or using the next slower shutter speed. Each negative EV value is the same as using a smaller f- stop or faster shutter speed. Turn Off EV Adjustment Don't forget to turn off EV adjustment after you use it. Some cameras retain this setting even if you turn off the camera and turn it back on. EV adjustment No EV adjustment With EV adjustment Focus Focus Range Lower-cost cameras with non-zooming lenses may not have focusing abilities at all; they provide sufficiently sharp focus at normal shooting distances (a few feet and farther) and, possibly, at a particular close-up distance (typically 18 to 24 inches). More expensive cameras have automatic focus that adjusts for the best setting at any distance. One of the basic rules of photography is to get as close as possible and crop out extraneous material. Close up focus and photography is particularly important with digital cameras, because any wasted subject area translates into fewer pixels available when you start cropping and enlarging your image. Page 11

12 Digital Photography Image Size file size Image Size print size on-screen size Page 12

13 Image size File size Affected by resolution -how many dots per inch examples 72 dpi 72 ppi 100 dpi 200 dpi 300 dpi People often scan images at 300 dpi Cameras often take pictures at 72, 100 or 150 The Myth of Resolution True or false: You can never be too rich, too thin, or have too much resolution in your digital camera. Draw a 4x4 grid at 4 dpi then an 8x8 grid at 8 dpi Image size File size Affected by total number of pixels example 1078 x 980 vs. 640 x 480 Taking a picture at 6mp resolution will create an image with many more pixels than taking it at 3 mp Image size File size The trade-off is Quality vs. compression level Affected by Compression or lack of jpg/jpeg photos gif line drawings png same as gif tif, bmp, psd are uncompressed Page 13

14 Compress Photographs as.jpg Incorrectly saved as.gif not enough colors avail Compress line art or cartoons as.gif or.png Compress images with few colors as.gifs Incorrectly saved as.jpg blotchy noise Page 14

15 Image size Print size Affected mostly by resolution (dpi) calculate this: a 900 x 900 pixel image at 300 dpi will print how wide? Image size on-screen size on-screen size Affected by image resolution (dpi) screen resolution most common is 100 dpi Don t be fooled by the size on the screen; it has only a small relationship to the size of the file. A 900 x 900.jpg can have a smaller file size than a 300 x 300.tif calculate this: a 900 x 900 pixel on a 100 dpi screen will take up how many inches of screen width? Page 15

16 Digital Photography Transferring camera pictures to your computer Connecting to your computer Use cable (usually comes with camera), or Pull out memory card and insert into card reader attached to your computer Page 16

17 Transferring the files Usually several methods to choose from: Install software that came with the camera and follow its prompts Use Windows Camera and Scanner Wizard Use the Download Manager (Adobe Photoshop Elements) or other software included with your image editor Treat camera as another drive letter and dragand-drop or copy Using Windows Camera and Scanner Wizard to transfer photos 1.After connecting the camera to the USB port, turn it on. 2.The Device Connect Autoplay dialog box appears on the Windows desktop. 3. Click the Scanner and Camera Wizard to select it. 4. Click OK to start the Scanner and Camera Wizard. Using Windows Camera and Scanner Wizard to transfer photos 5. Click Next to display the photos in the camera. 6. Click a photo you want to rotate. 7. If necessary, click the Rotate tool to turn the photo upright. 8. Click Next when you have reviewed all the photos. Tip: Skipping Photos Clear the check box next to any photo if you don't want to Page 17

18 copy it. Tip: Rotating Photos Some digital cameras automatically rotate photos for you. If not, it's easier to work with your photos later if you rotate them with the wizard before you copy them to your computer. Using Window s Camera and Scanner Wizard 9. Type a name for the group of pictures. 10. To select a new folder for the photos, click Browse. 11. Click the folder you want to use for the photos. 12. Click OK to continue. TIP: Making Room for New Photos To free up room in your digital camera for more photos, click the box next to Delete pictures from my device after copying them. Page 18

19 Using Windows Camera and Scanner Wizard to transfer photos 13. Click Next to copy the photos. 14. After the photos are copied, click Next to continue. 15. Click Finish to complete the wizard and view your photos. Using Windows File Manager to transfer photos 1. Turn on the camera after connecting it to the computer or inserting your memory card into the memory reader 2. The Windows XP Autoplay menu is displayed. 3. Click Open Folder to View Files. 4. Click OK. 5. Copy or drag-and-drop images to your computer. Page 19

20 Digital Photography Editing Image Editing Programs There are many editing programs available look for key features An editor is often included in Microsoft Office under Microsoft Office Tools Microsoft Office Picture Manager Simple editing available at Adobe Photoshop Elements is more fully featured Picasa from Google looks promising Page 20

21 Image Editing Key Features Crop tool to cut away unnecessary portion of image Resize tool to reduce the number of pixels Resampling to reduce the dpi Crop examples Crop Symbol To crop in Photoshop Elements, click to select the crop tool, then draw a rectangle around the area you wish to keep. Press Enter to finish the crop Crop examples Press Enter to finish the crop Page 21

22 Cropping in Windows Picture Manager Click the crop link, then move the sides of the selection box to encompass only what you want to keep The editor may not show your image in its correct size Image on previous slide is shown at 18% of real size much bigger than I want! Double-check the screen size of your image Change the zoom amount to 100% to view the image as actual size Crop examples Page 22

23 Resize example Adobe Photoshop Image -> Resize -> Image Size command in Adobe Photoshop Elements Change the width or height in pixels or inches Resampling in Windows Picture Manager I changed the resize percent to 50 (from 100). This is just before I click ok. Instead of 2167 pixels wide, the image will be 1084 pixels wide. Resample example Uncheck the resample image checkbox Change the resolution number For example, doubling the resolution from 72 to 144 will decrease the width by half Page 23

24 Helpful Web Sites Camera reviews Free online editing, limited features Share your photos, view other s photos, search by tags Search for bargains, discounts and rebates Page 24