Shooting RAW vs RAW and JPG

Discussion in 'Digital Cameras' started by Not4wood, Nov 9, 2007.

  1. Not4wood

    Not4wood Guest

    In the discussion of "Reluctant Wedding Photographer",

    There ended up a discussion of shooting RAW to make sure you had enough
    details as a just in case.
    Then if I agree with this, because I shot a RAW the other day for the first
    time and was impressed on the quality of the details.
    We didn't have this option when we shot Film, so why would we need this
    option now?? We had a nack for noticing a bad shot or a blink or just
    something sticking out of a head to make the shot over again.
    Why would you shoot RAW and JPG at the Wedding because of memory space?
    Wouldn't RAW be enough details if your going as a just in case anyway??

    Now, high setting Fine in JPG with a larger image is 8 bits in my 10 MP
    camera. RAW high quality Fine, large image is 12 bits. How would someone
    get more bits per pixel then 12? I saw a mention of possible more but I
    didn't have time to read the article to early this morning and now I cant
    find it.


    TIA
     
    Not4wood, Nov 9, 2007
    #1
    1. Advertisements

  2. Not4wood

    Hmmmm... Guest

    It's not a matter of shooting and noticing if the shot might have turned out
    wrong. You have to understand the limitations of digital vs. analog methods of
    capturing images. Film has much more exposure latitude and dynamic range than
    any digital camera will ever have (at least for now). Using RAW is one way of
    retaining some of that dynamic range that the camera will throw away in its more
    simple (faster) RAW to JPG conversion.
    Because someone didn't plan ahead or didn't have enough experience to know how
    much memory space they'd need for the event? Much will also depend on how
    extravagant that ceremony is and how many guests attend. If they don't plan
    ahead properly then they might have to give up on RAW altogether and just use
    JPG only, or chance missing out on photos from the reception.
    Very much so. But since the JPG file along with it takes up so little additional
    space, the JPG is easier for proofing and previewing all your shots. Allowing
    you to pick out the very best ones to which you want to allocate your time to
    processing the accompanying RAW files (time consuming, especially for the
    newbie). The JPG files also make for a simpler way to hand a copy of all the
    photos to anyone that requires them. Most likely to people who have never heard
    of RAW nor have the expertise to view/convert them properly.
    Cameras can have RAW file data in 10-bit, 12-bit, and 14-bit formats (so far).
    When it is imported/converted into your RAW capable editing software, the
    missing bits are padded out by null data (0's). You can't save only 12-bits of
    information in a data-storage format that requires all data being in 8, 16, 32,
    or 64 bits. You can discard 4 bits from that 12-bits of data to get an 8-bit
    image, or pad it out with null bits to fit into the 16-bit format. Even though
    those null bits are all 0's (zeros), they will still show up as a larger
    file-size. There are also various forms of compressed RAW data that do not do
    this (just like the original smaller 12 bit file right from the camera). But
    they require software capable of reading them. More often RAW data is converted
    into the larger TIF or PNG (8 or 16 bit) file formats which are more
    cross-platform compatible and able to be read by more programs.

    I'm not a strong advocate of RAW, only using it when absolutely necessary. And
    only then when the camera I am using has proven itself to not have a very good
    RAW to JPG conversion internally (only one of my cameras benefits greatly from
    using RAW more often because of this). In the cases of weddings where you are
    dealing with subjects dressed in white and black in often dimly lit surroundings
    to full sunlight outside of the buildings, the extra dynamic range available in
    the RAW files can help compensate for the limitations of digital cameras--a
    technology that cannot easily capture those subtle differences of black cloth in
    shadows and white folds of a dress in sunlight. It has its uses. Especially if
    you are not well verse in what your camera can and cannot do, and you need some
    backup insurance. If you are well experienced with your particular camera,
    photography in general, and your camera's RAW to JPG methods are exceptional
    (many new ones are) then you may not even need RAW and still be able to obtain
    images just as well from the JPG files.

    Only you will know your own limitations and the limitations of your equipment,
    and what needs to be done to get the best out of both.
     
    Hmmmm..., Nov 9, 2007
    #2
    1. Advertisements

  3. Not4wood

    Bill Guest

    I can't speak for all versions of raw, but the freeware Irfanview
    reads and displays the raw files from my Canon 30D. This is what I
    use to preview the files before converting and saving the ones that I
    want to print with Photoshop Elements.

    You can even play with adjustments to the files to get an idea of what
    tweaking might accomplish.

    Bill
     
    Bill, Nov 9, 2007
    #3
  4. Not4wood

    Richard H. Guest

    Exactly. RAW+JPEG is handy while migrating to RAW, or if you need to
    use JPEGs on the spot. Otherwise it doesn't add value.

    E.g., Nikon's RAW file format embeds 2 JPEGs in the file - one
    thumbnail, one full-res low-quality ("Basic JPEG"). Shooting RAW+JPEG
    writes the same Basic JPEG and thumbnail image to a separate file, for a
    total of 5 copies of every shot - so, it's practical only if you really
    need the JPEG file on-the-spot.

    It's enlightening to compare the camera-generated JPEG to the same image
    converted externally from RAW. I nearly always prefer the one converted
    in post-process (even when batch processed).

    To address a common argument against RAW - shooting RAW doesn't add
    post-processing time. Free tools like Irfanview can batch convert to
    high-quality JPEGs at a rate of 80+/min. The issue with time is whether
    folks can be disciplined about not tweaking like crazy, now that they
    can. :)

    Cheers,
    Richard
     
    Richard H., Nov 9, 2007
    #4
  5. Does RAW seem a lot slower to save to anybody - or is it just me?

    Seems to make sense: larger file, longer time to write....OTOH,
    no conversion necessary....

    Some time ago, I read an assertion that for PCs there's a
    crossover point for compression/bandwidth/CPU capacity. i.e.
    Beyond a certain point the CPU can de-compress data fast enough
    that the short time needed to read the compressed data outweighs
    the processing time for a net gain in throughput speed.
     
    (PeteCresswell), Nov 9, 2007
    #5
  6. Not4wood

    Marty Fremen Guest

    It's worth getting as fast a memory card as possible. I was using a cheap
    "own brand" card that claimed to be 133x but turned out to be more like
    33x, or possibly not even that. After reading some benchmark figures I
    replaced it with a Sandisk Extreme III which had topped the test and my raw
    save time immediately halved (going from unbelievably slow to just slow...)

    Having said that, I think the word "Extreme" in the name actually refers to
    the packaging: the box the SD card came in was so big the postman couldn't
    fit it through the letter box!
     
    Marty Fremen, Nov 10, 2007
    #6
  7. Not4wood

    Marty Fremen Guest

    You can't simply multiply 9 x 12 bits to make 108 bits though. If you add
    two 12 bit numbers you get at most a 13 bit number, and so on. Adding
    together nine numbers would give you just over 3 bits more depth, so 16
    bits per channel is enough.

    Also if you look at what is being done with the data, there isn't really
    more genuine information than the original 12 bits. Suppose we were
    interpolating a pixel between two 8 bit pixels with values 252 and 253. The
    intermediate pixel gets a value of 252.5 which needs 9 bits to represent
    it. But that 9th bit is illusory. Since we're interpolating, the true value
    of the pixel in question could equally be 252 or 253, especially if one
    of the adjacent pixel values include some noise, which is quite likely. It
    could even be another value entirely. The only justification for keeping
    the extra bit depth created by interpolation is because it will give us a
    smoother result if we later reprocess the image, and to prevent
    inaccuracies from compounding.

    At the end of the day you can't get more than 12 bits of real information
    per pixel from a 12 bit raw unless you are downsampling, in which case each
    consolidated pixel will indeed have a greater precision than the individual
    component pixels.
     
    Marty Fremen, Nov 10, 2007
    #7
  8. Per Marty Fremen:
    Might also refer to durability. Mine's been through the wash in
    a pants pocket - at least twice.... no problems.
     
    (PeteCresswell), Nov 10, 2007
    #8
  9. Not4wood

    Richard H. Guest

    It's the write time. The files are larger than JPG and writing to the
    Flash is the slowest step.

    Before investing in blazing-fast flash cards, reference this site for
    your particular camera to find the best bang-for-buck flash card (or to
    find the fastest card reader for your card model):
    http://www.robgalbraith.com/bins/multi_page.asp?cid=6007-7906

    Card speed really matters only in a couple areas though... First, if you
    are shooting so fast that you exhaust the rapid-fire buffer in your
    camera - the camera will stop taking shots until an image can be written
    from buffer to the flash card. Second, if you're really concerned about
    how long it takes to download images from the card to your PC (in which
    case, the reader can be a performance factor). Otherwise, the
    performance of the card doesn't matter as much.

    Cheers,
    Richard
     
    Richard H., Nov 10, 2007
    #9
  10. Not4wood

    Douglas Guest


    You left an important detail out of your question... The brand of the
    camera you use! Why is this important?

    Because (for example) Olympus have a large, fine jpeg capture without
    compressing the image data the way Canon do. The result is a JPEG file
    which contains as close to RAW image data as is possible to have in a
    conversion.

    How it works is intriguing and raises the question of why do Canon and to
    a lesser extent Nikon apply so much compression to their jpegs. The
    notion you have an extra 3 stops (1.5 either side of the exposure value)
    "up your sleeve" shooting RAW is a falicy.

    If you shoot at the extremes of dynamic range (white wedding dress, black
    suit, bright sunlight)You need that 3 stops on the shadow side of the
    exposure just to tame the UV light reflecting off the white dress.

    Some camera manufacturers are better at producing a DSLR more closely
    resembling the traits of a film camera. They are also mindful that ultra
    low compression in a JPEG produces a file very, very close the RAW data
    file and without the hassles RAW files cause.

    If Microsoft manage to pull off their lossles image compression format
    format; "WDP", JPEGs and MS's WDP format will dominate the scene in a
    year or two anyway.

    You should never forget that film images are developed in lots of 36
    (more in some cases). When you "develop" RAW images in bulk lots, you
    have additional expendeture for the software to do it and still need to
    maintain Photoshop or a similar program to manipulate images before
    printing.

    http://www.weddingsnportraits.com.au/previews/scott-katrina/ was shot
    entirely with a Panasonic FZ50 in JPEG mode after the shooter's Fuji s5
    was droped early in the proceedings. You can import JPEG files into Adobe
    Camera Raw (ACR) and Photoshop "lightroom". You have almost as much
    control over them as a RAW file.

    Douglas
     
    Douglas, Nov 10, 2007
    #10
  11. Well said. But until the HDP/WDP image format becomes more common, and I wish it
    would because PhotoLine 32 has supported this since Vista came out, then it
    becomes difficult to use standard JPG 8-bit color depth when trying to "stretch"
    some details out of the shadows or reclaim them from highlights. Without the 16
    bit support of HD-Photo / JPEG-XR format you'll still get the annoying
    posterization effects that happen when editing with the limited amount of data
    at those extremes.

    The benefits of that newer image format are great. I just wish all my
    applications supported it. If they did I'd be saving all my edits as HDP files.
     
    clarence_anderson, Nov 10, 2007
    #11
  12. Per Richard H.:
    From that, I'd guess that one of the diffs between a
    professional-level camera and my D70 is the size of the
    rapid-fire buffer.

    ?
     
    (PeteCresswell), Nov 10, 2007
    #12
  13. Not4wood

    Richard H. Guest

    Technology will advance, and some products will always have certain
    advances before others - it makes for competitive differentiators in the
    market. It's good to hear there's progress in lossless compression, but
    there's no saying a new compression algorithm will be exclusive to a
    particular format for long (especially when the manufacturers have
    ability to update their RAW format).

    As to JPEG compression in-camera, the level is often selectable. But
    the issue is less about the compression technology being applied and
    more about the fact that the sensor is collecting data in a wider
    pallette than the 8-bit JPEG format can support (before any compression
    step), so the pallette is necessarily reduced in a one-way conversion -
    and in doing so, the camera is making decisions for you that become
    irreversible. That's what RAW is about.

    Perhaps MS' new file format will establish a new standard that addresses
    this, but it'll take a long time to gain broad acceptance - JPEG 2000
    and PNG made improvemens beyond JPEG years ago but still aren't
    generally supported. In the meantime, RAW offers the option of
    preserving the detailed data, allowing for multiple conversions outside
    the camera to suit the user's preference.

    As to cost and overhead for conversion... Irfanview is free and converts
    a variety of formats to JPEG at a rate of more than one per second in
    bulk. Neither expensive, nor slow. Likewise, Photoshop Elements is
    under $100 and an excellent value for most folks; you need it (or
    something similar) for editing anyway, and manually adjusting a RAW when
    importing adds less than 15 seconds. (And it too supports bulk conversion.)

    The point is... neither RAW nor JPEG is the perfect answer for everyone
    - it depends on the shooter and their preferences. RAW's not the
    expensive burdensome process that folks try to make it out to be, but
    it's also not for everybody; a lot of folks are happy with the in-camera
    defaults and convenience of JPEG output.

    (Personally, I've seen enough side-by-side comparisons with my own gear
    that I only shoot RAW now; I'm happier with the results, and it's saved
    the day enough times that's it's well worth it.)

    Cheers,
    Richard
     
    Richard H., Nov 10, 2007
    #13
  14. Not4wood

    Richard H. Guest

    Bingo. And faster rapid-fire (continuous shutter) as well. And you'll
    find JPEG uses less buffer, so it supports more rapid-fire shots in one
    burst. Even more if you go for smaller image sizes.

    As models progress towards "pro", they also tend to bring more features
    out of the menu and onto dedicated buttons. And they enable software
    features that otherwise could be offered on all models (like CLS flash
    control, mirror lockup, etc.)

    Recently, a friend handed me his D40 or D50 to snap a sunrise shot. I
    found myself stumped trying to use it in manual mode - it only has one
    command dial, and apparently the aperture control is buried behind a
    menu. It's tuned for its market segment - simpler controls for their
    most common uses.

    Cheers,
    Richard
     
    Richard H., Nov 10, 2007
    #14
  15. And the other variable is how quickly the camera can clear space in the
    buffer by spooling files to the flash card. That's a function of both
    the camera and the card, of course. With a fast card, my D80 can keep
    shooting large JPEGs at 3 fps well beyond the 23 shot buffer. Nikon
    limits bursts to 99 shots for some reason, but if you stop at 99 and
    instantly restart, you can keep going at full speed without needing to
    wait for the buffer to clear.

    Cameras with faster bursts will outrun the ability of cards to write
    data quickly, so full buffers will force a slowdown in the burst.

    -dms
     
    Daniel Silevitch, Nov 10, 2007
    #15
  16. Not4wood

    Ron Guest


    I shoot Nikon and in RAW only mode.
    It just waste space to shoot with JPG's. On a 8 GB card that means over
    100 more photos on the card. If I need a JPG I can always extract it from
    the RAW file, it takes less than a second per shoot once the RAW NEF files
    are downloaded to the PC.
     
    Ron, Nov 11, 2007
    #16
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.