Digital Photography FAQ

Discussion in 'Digital Photography' started by atwl77, Aug 18, 2003.

  1. atwl77

    atwl77 Just Started

    Q: How do I read the numbers on a digital camera's lens?
    A: You will usually see figures such as 6.3-63mm F2.8-3.7 Ø49mm. The 6.3-63mm refers to the len's maximum wide angle and maximum zoom settings. If you are familiar with film SLR, these numbers are not related to your 35mm values. Most digital cameras have smaller sensor sizes and have to be converted to 35mm-equivalent in order to be properly read. The F2.8-3.7 refers to the camera's maximum aperture at wide angle and at telephoto ranges. So at maximum wide, the largest aperture for this example is F2.8 and at maximum telephoto, the largest aperture is F3.7. The Ø49mm refers to the diameter of the lens thread and is only useful if you intend to attach filters and conversion lenses to your camera.

    Q: Why do my pictures turn out blurry?
    A: This can mean several things. You may have tried to take a shot in low light (such as indoors) without a flash. Usually a camera's metering will select a slow shutter speed for this kind of shot, and if your hands are not steady enough your image will appear blurry.
    Also, your camera may not have obtained a proper focus for the shot. Consumer digital cameras use a technique called Contrast Detection to focus properly. If your subject has low contrast, or in low light situations, your camera may not obtain a proper focus.
    In order to focus properly, you should point your camera to a high constrast part of your subject (sharp vertical or horizontal lines will help), and press the shutter release button halfway. Usually a camera will use a green light or dot to represent a good focus. If it is blinking, it could not focus on your subject and you should re-focus your shot.
    Once the camera has obtained a good focus, re-compose your shot and press the shutter release all the way down.



    Q: Any tips for a beginner?
    A: Digital is cheaper than film. Just keep shooting and shooting (always have your camera with you for this). Keep (and print) your good shots; analyse your bad ones and figure out how you could have done better before discarding it.


    Q: Is digital better than film?
    A: Yes and no. It all depends on the photographer and his purpose for taking a shot. For me, I prefer digital. You can instantly see your results and re-shoot if it was a bad shot. You can upload your images to an image editor for post processing. You can choose which shots that you want to keep before printing them. Digital is also great for learning because you can experiment with all kinds of settings and see the results immediately.



    This FAQ will be continually updated as more questions come to light.

    :)atwl
     
  2. Trinity

    Trinity Little Kiki Staff Member

    more faq's




    (from Best Buy's web site)

    Q: Can I record live action video and sound on a digital camera?
    A: Most digital cameras cannot record video or audio, although Sony's Digital Mavica line is an exception. Digital cameras can be used in much the same way as regular cameras, with the advantage of producing the photos digitally. So, the wild polka moves at the next wedding you attend will be still shots, unless you want to spend the dough on one of those high-end digital models or bring the camcorder. And yes, you'll have to imagine the clever dialog. Just remember the fun you'll have e-mailing the photos.

    Q: What accessories are essential for uploading pictures from camera to computer?
    A: As usual, the accessories complete the outfit. While you can load images into your PC by simply connecting appropriate cables between your camera and the computer's serial or (preferably) USB port, you may find this process cumbersome. You may wish to consider investing in an optional adapter that will allow you to upload images stored on removable media directly into your computer's floppy drive. Floppy disk adapters (and hardware reader/writer peripherals) are available for all 3 common flash memory formats.

    Q: How do I get my pictures developed?
    A: Because the information is stored digitally, there is no film and thus no developing of film. The digital files can, however, be printed. The quality of prints is determined by a combination of the quality level of camera, printer and paper. Prints can also be downloaded to online photo processing companies including shutterfly.com, ofoto.com, or Kodak's photonet.com.

    Q: A lot of Web sites these days feature live video feeds. How do they do it?
    A: The development of increasingly affordable Web cameras makes it possible. Also known as PC video cameras, Web cameras capture images digitally and let you send pictures or video clips over the Internet. Most are easy to connect and use. With the video conferencing software that usually comes with the product, you can hold a real-time video conference with someone halfway around the world if they also have a Web camera. Even if the recipient doesn't have an Web camera, they can still view video clips and still images you send them.

    Q: If I use an Web camera to create video e-mail, will the recipient be able to view it without special software?
    A: You can send still photos and videos to anyone through e-mail and, as long as they have a relatively up-to-date computer system, they shouldn't have a problem viewing them. However, to communicate in a two-way, real-time video conversation, you and the other participant must have compatible program software. Always check compatibility with the camera manufacturer before purchasing any video conferencing product. Minimum system requirements for e-mail software are AOL 5.0 or above, Microsoft Outlook Express or Netscape Mail.



    Q: So if I decide to add a Web cam to my system, what should I look for?
    A: Evaluate your needs and consider several specifications before you decide to add an Web camera to your system. Cameras come with parallel or USB connections, and still image compression formats are available as BMP, TIFF and JPEG. Also, consider whether it has a built-in microphone, and evaluate the quality of video clips, measured in frames per second (FPS).

    Q: What makes one Web camera better than another?
    A: With just about any technology, there are considerable differences in features and quality; both are usually reflected in the prices of cameras. Consider your needs and shop accordingly. An important consideration is the still image capture (360 x 240 is lower resolution than 640 x 480), the video frame rate (24 frames per second is slightly lower-quality video; 30 is better) and the number of colors the camera can support (16 million vs. 24 million). Some cameras come complete with a microphone input and software so that you can combine audio with video. If you want to take pictures outside of your computer work area, you'll enjoy the flexibility of a detachable camera.

    Q: Is it safe to take my digital camera underwater?
    A: No.

    Q: What is JPEG and what does it mean?
    A: JPEG is the most common encoding format for compressed digital still images (the name comes from Joint Photographic Experts Group, the international organization that developed the standard). Basically, the compression of a digital file decreases its size, allowing more efficient use of data storage space. The higher the JPEG compression factor, the smaller the file size and the faster the downloading.

    Q: What is the difference between optical and digital zoom?
    A: Most digital cameras have an optical zoom, which increases magnification via lens manipulation The image is changed before it hits the CCD so each pixel has unique information. Resolution stays the same when the image is enlarged optically, which means the picture is still crystal clear. The quality of the optics is important because it determines the final quality of the photo. A digital zoom is used to multiply the zoom ratio of a fully extended optical zoom. Because the image is changed after it hits the CCD, pixelization occurs when you enlarge it. Essentially, a digital zoom isolates a sector in the center of the optically derived image and blows it up. Since the pixels themselves are enlarged, the image doesn't gain any actual detail. The picture won't get any clearer, just bigger. In short, a subject's detail is actually captured more faithfully with an optical zoom than a digital zoom.



    Q: Why would I want to eliminate picture files?
    A: Removing unwanted or poor quality picture files maximizes the data storage capability of your camera. Any digital camera will give you this option, but the process can be tedious. If you don't seem to have adequate data storage, consider purchasing flash memory cards for your camera. Additional flash memory lets you store more images.

    Q: Will my pictures look as fabulous as 35mm pictures?
    A: In general, the clarity of digital cameras is quickly catching up to traditional SLR cameras, and is dependent on resolution and printer quality. Up to an approximate 8" x 10" image size, a 2MP model can deliver "photo quality." However, most consumers are interested in digital cameras primarily for the ability to e-mail and store images in a computer. The standard screen display operates at just 72 dpi, meaning that almost any digital camera (even one with less than 1MP resolution) can provide ample image quality for sharing photos via e-mail. Assess how you intend to use digital technology when making purchase decisions.

    Q: Where do the pictures go since my camera does not have film?
    A: Your photographs are stored digitally within the camera's flash memory.

    Q: What is a megapixel and how many do I need?
    A: Megapixel (MP) is a term describing digital camera resolution, referring to the total number of pixels in the square area of the CCD (charge-coupled device). One megapixel equals a million pixels. For posting pictures on a Web site, e-mailing them or making slide shows for your PC or TV screen, low- to mid-level resolution (under 1 megapixel) will suffice. If you intend to print your pictures out and need a high-quality, data-rich image, you want at least a 2-megapixel model. Remember that the capabilities of your printer and the paper you use will bear heavily on the quality of printed photos, regardless of the resolution of your camera.

    Q: How many pictures can I take?
    A: You can store only as many pictures as will fit in the total memory storage capacity of your camera. Cameras are built with varying amounts of on-board memory. How many pictures that memory can store depends on several factors, including the resolution at which you're shooting and the compression factor (if any) applied to the images. But for practical purposes, you'll probably want more. The on-board memory in most digital cameras can be upgraded by adding removable flash memory cards, which are available in varying capacities depending upon the format.



    Q: Are SmartMedia, CompactFlash and Memory Stick similar?
    A: They are all formats of removable flash memory used in small portable devices such as digital cameras. Manufacturers typically choose one format for an entire line of digital cameras.
     
  3. Chai

    Chai Administrator Staff Member

    Hmm...this guide seems a little old, but most of them still apply today. Anyway, if you didn't write this yourself, please mention the source of the FAQ. You wouldn't want any trouble, right? ;)
     
  4. lung

    lung Just Started

    I have a Question: What do the different ISO numbers usually mean? I notice that with a higher ISO setting, the shutter speed is slower... But apart from that? Which ISO setting is best used in which environment?
     
  5. Dashken

    Dashken Administrator!

    I have one questions too. How do you press the shuttle release 'half-way down'? The moment i press it, it takes the picture. :doh:

    What is recompose? :think:
     
  6. atwl77

    atwl77 Just Started

    Different cameras' shutter release buttons may handle or "feel" different... you have to experiment to find out where is your camera's "half-press" "sweet spot".

    Usually there's an indicator (e.g. green dot or light) that will confirm a "focus lock" - if you see that while pressing your shutter then you have that "half-pressed" position and you can hold that position while you recompose the shot.

    Usually you recompose when you want to focus on an object, keep the shutter half-pressed then re-frame the shot to look better (e.g. to have your subject somewhere other than the centre of the frame). Another example - if you want to take a photo of two people standing beside each other, you may want to focus on one person first, then recompose to have both people positioned better in the frame.


    :)atwl


    :)atwl
     
  7. Trinity

    Trinity Little Kiki Staff Member

    To flash. Or not to flash. That is the Question.

    I am wondering if it is better to take pictures without the flash,,, With a longer exposer. To avoid reflections/red eye. etc.etc. And at night. :think:


    (newbie) :oops:
     
  8. Dashken

    Dashken Administrator!

    When I use flash photographing something white, like a paper, I see nothing. :think: Just white overall. :?
     
  9. Chai

    Chai Administrator Staff Member

    If you are using tripod, avoid flash. Highly recommend flash for outdoor shots.
     
  10. atwl77

    atwl77 Just Started

    Well flash photography is a very complicated subject but usually applies to external flash units and studio strobes - these have better quality light compared to the camera's internal flash.

    So the general rule is, unless you have a good external flash and know how to use it, if you can get away with not using the flash then by all means do it. Otherwise, better to flash than to get a bad shot.


    :)atwl
     

  11. Generally in low light you will use a higher ISO and in bright light you can use a lower ISO. The lowest ISO you can get away with is best, as this will give the least picture noise

    Note : rest of post is based on my current understanding of ISO equivalents

    ISO on digital cams is confusing (well to me). On analogue cam it is a measurement of film sensitivity and with more sensitive film the film grains increased, reducing quality. On digital cams I think CCD is used to emulate this effect, having the same good and bad effect.

    So if a lower ISO is best, why change it?

    If you don’t need to don’t! But sometimes you must. Like when taking stop-action shot in low light, and astronomic photography. You can reduce the need to change your ISO with correct Aperture and exposure times (shutter speeds).
     
  12. Seblington

    Seblington Newbie

    Digital cameras as video cameras?

    just a note on Trinity's FAQ's, most digital cameras today can record video, but it is not of good quality as they are designed for picture taking. I have been interested in the video side of things on stills in most of the cameras I have had, from my early DSC-50 (10pfs @15sec intervals) to my current DSC-F717 (16fps no time limit). This is pretty poor to the Fuji 7000s (30fps 1 minuet intervals) and the best I have seen is the F828 (30fps no time limit) but I have heard problems about its focus whilst recording.
     
  13. elton

    elton WhAtSuPdOc

    I prefer took shoot without any flash... except it is too dark in the night then have no choice...

    But if u manual set in the dark night use around 2sec Shutter i also can take a dark night pic also.... if u can hold you camera without shaking...

    TIPS.... in order to hold your camera properly.... You can hold it stick to your chest and hold your breath then take the shoot... it will help for those ppl hand keep in shaking...
     
  14. jinongman

    jinongman Newbie

    How does the aperture work ?
    How do i know how much for what conditions ?

    and what about the focus ? :confused:
     
  15. zy

    zy zynine.com Staff Member

    your camera have manual aperture settings? :mrgreen:

    its something to do with the opening in the camera which aloows the light to go through ler..

    the smaller then number the bigger the opening ..
    smaller number means faster shutter.
     
  16. u suck.com

    u suck.com ■ ■ ■ ■

    errr...what does aperture mean ? is it the ISO thing? :oops:
     
  17. CleanSerious5

    CleanSerious5 Banned

    no Dc can take night scene perfectly w/o tripod 2date?
    :pray:
     
  18. Chai

    Chai Administrator Staff Member

    Aperture is the opening size of the shutter.

    ISO is the light sensitivity. Lower ISO = less sensitive to light = darker picture.
     
  19. zy

    zy zynine.com Staff Member

    :wall: you should not move the camera when you are trying to take night sceneshots :wall:

    tripod is the best method because you can adjust it :wall:
     
  20. CleanSerious5

    CleanSerious5 Banned

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