more about the camera design I would like to have

Discussion in 'Digital Photography' started by Guest, Oct 10, 2008.

  1. Guest

    Guest Guest

    In the previous thread, I coined the term "single lens direct" or "single lens
    display" or "SLD" to refer to my design. A summary of the design:

    1. The viewfinder that is normally viewing through the taking lens via a
    flip-up mirror, ground glass focusing screen, and a pentaprism, in an
    SLR design, now view an LCD screen. I had suggested that LCD screen
    can be placed where the focusing screen is on an SLR, and be viewed via
    the same pentaprism. Others suggest to just skip the pentaprism and do
    a straight view of the LCD screen. It would also be possible, if some
    camera shape design needed it, to just use a mirror and electrically
    reverse the LCD display as needed.

    2. The sensor would always operate in "live view" mode. A camera can have
    both an viewfinder LCD display, as well as a back LCD display (yes, two
    LCD displays). The "face is close" detector that shuts off the back LCD
    in SLR cameras now can also turn the viewfinder LCD display on. One way
    or the other, you see through the taking lens electrically live. Focusing
    can use the techniques SLR with "live vider" mode already have, like doing
    software magnification and/or contrast focusing. Focusing points can be
    put anywhere desired.

    2. The flip-up mirror is now gone. This leaves room inside the camera for
    other things. I suggested super wide angle lenses can be placed closer
    to the sensor. There was a heated debate about this, but my take on the
    "conclusion" of that is wide angle lenses are less complex when designed
    this way, and the real issue is light falloff at extreme angles on the
    sensor. Whether it is easy or hard to solve, it is solvable, and I even
    suggest more than one way to do it exists.

    3. I suggested that this SLD design should be made to make use of (nearly)
    all SLR lenses in that manufacturer's line. So for Canon, that would mean
    making EF and EF-S lenses normally work (or just EF lenses for a full frame
    SLD model).

    4. For a wide angle lens closer to the sensor than can be done with an SLR,
    such a lens would have a protruding rear element if the mounting distance
    remained at the same point as for an SLR. There is the risk that someone
    might try to mount such a lens on an SLR, possibly damaging both camera
    and lens. I suggested a slightly variant mount with an adaptor for real
    SLR lenses on an SLD camera. Others suggested this would actually be more
    complicated for both the average photo hobbyist as well as professional.
    And I think they win that argument. So a lens with a protruding rear
    element used on an SLR invokes a hard learned lesson.

    5. It was suggested that we should move away from a focal plane shutter and
    return the leaf shutter, which is the basis for large format view cameras
    and many other "smaller" cameras, as well. I hadn't considered this when
    I suggested the SLD design, but it clearly is the way to go. But it should
    do this in a migratory way, keeping the focal plane shutter in SLD cameras
    for a number of years until the lens lines upgrade to have leaf shutters.

    6. Despite what I think are clear advantages in the SLD design over SLR for
    most things, there are times where at least a focal plane shutter have
    some benefit, and there could still remain some use for optically viewing
    through the taking lens. So I don't see the SLR going completely away in
    my lifetime, and there might always be at least some SLD cameras with a
    focal plane shutter, too.

    7. In-camera filters, either slide-in from a side door, or inserted from the
    front with the lens off, might be more practical than on-lens (front or
    rear) filters. The electrical sensor needs a filter to block both IR and
    even some UV. Glass passes only a limited amount of UV, so it has not been
    a big issue with film, even though film is generally very UV sensitive. A
    UV blocking filter has been common on the front of many lenses. But with
    digital, an IR blocking filter is critical for accurate visual spectrum
    photos. If this is done with a slide in filter, that leaves open options
    to use other filters instead. But those filters either need to have their
    own IR blocking, or we need 2 filter positions, or one filter cartridge
    that can have 2 filters on it.

    There is one more idea I thought of today. And this is not specific to SLD,
    although doing it in an SLR would probably need to change the camera frame
    construction a bit. This idea is to increase the sensor dimensions from the
    3:2 aspect normally used with a landscape orientation (which requires the
    camera to be rotated 90 degrees for portrait orientation), to a full 1:1 at
    the full size. So for a full-frame sensor this would be 36mm x 36mm. For an
    APS-C size, this would be around 22mm x 22mm. Not every camera needs to have
    this. I could be a premium feature on advanced cameras. The idea is to have
    the electronics simply use the appropriate portion of the sensor based on the
    desired picture orientation. If you want landscape, you use the portion of
    the sensor that is 36mm wide by 24mm high. But with one button, you can have
    the camera use the portion of the sensor that is 24mm wide by 36mm high. As
    most lenses are round and cover a complete circle of at least 43.2666mm wide,
    which is the corner to corner distance of 36mm x 24mm, this should work. The
    only issue I see at the moment is with lenses that have integrated hoods with
    a rectangular opening oriented in landscape mode the way the lens would be
    mounted to the camera. When using these lenses, fall back to the classical
    method: turn the whole camera (the smart camera will beep and warn about the
    change to portrait orientation when said lens is mounted).

    Such a sensor could leave out the corner parts that don't get used by either
    orientation. Or the sensor could also be made to allow other aspect ratios
    that fit within the standard coverage circle for that sensor size. A square
    (1:1) aspect ratio could be 30.59mm x 30.59mm and fit this coverage. Other
    aspect ratios could be used in ways that one dimension is a bit wider that if
    that same aspect ratio were derived from cropping the standard size. If the
    sensor is going to be upgraded to do the landscape/portrait switch, then these
    other aspect ratios came almost free (the cost it not cutting out as much in
    the corners of the sensor, and writing some more firmware).

    Why would anyone want a 1:1 taking aspect ratio? How about circular fisheye?

    Also, maybe an SLR could be designed in such a way that when its mirror does
    go into a locked up position, it optically flips the light path to allow an
    LCD screen to be seen in the viewfinder. Then we have an SLR/SLD combo. That
    and a focal plane shutter locked-open mode, and you can have a real combo.

    I'm sure a few people will come up with descriptions of why they don't need
    these features. I do think that over time (10 years or so after SLDs first
    come out) a lot of people will end up preferring the SLD over the SLR.
     
    Guest, Oct 10, 2008
    #1
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  2. Guest

    Alex Monro Guest

    <snip details>

    Looks like the Olympus / Panasonic micro four thirds covers your points
    1 - 4, at least.
     
    Alex Monro, Oct 10, 2008
    #2
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  3. Guest

    Guest Guest

    | wrote:
    |
    |> In the previous thread, I coined the term "single lens direct" or
    |> "single lens
    |> display" or "SLD" to refer to my design. A summary of the design:
    |>
    | <snip details>
    |
    | Looks like the Olympus / Panasonic micro four thirds covers your points
    | 1 - 4, at least.

    Right. And that was mentioned in the other thread. But the four-thirds
    system is a reduced resolution system. My goal would be to see a system
    with at least some cameras at full frame, and lenses that can cover it.
    That, in addition to the further details that has been added. Four-thirds
    would not satisfy my needs, and probably not that of many others, either.
     
    Guest, Oct 11, 2008
    #3
  4. Guest

    dj_nme Guest

    Perhaps "slightly increased image noise", rather than "reduced
    resolution" due to a smaller sensor would be more accurate?
    There are currently 4/3 DSLR cameras with the same or higher pixel count
    (resolution) than similar price-ranged APS-c DSLR cameras, with no real
    reason why this won't continue.
    I believe that it depends on what your goal is, if it's the smallest
    interchageable lens camera with a large sensor and affordable price,
    then totally disregarding the Mu4/3 standard seems a tiny bit foolish to me.
    The most attractive part of the Panasonic DMC-G1 is it's 1.4mp EVF,
    although the "mini SLR" styling doesn't make the smallest it could be.
    If the mock-up Mu4/3 that Olympus was displaying at FotoKina had that
    EVF in the top left-hand corner on the back of the body, then I think it
    would be a really great design.
    The problem with that is that if the LCD is articulated from the left
    hand edge, then it would have to be smaller so as to not interfere with
    the EVF, but it could be articulate on the top or bottom edge instead.
    The same design features could just as easily be incorporated into a
    body with a larger (APS-c or 35mm FF) sensor, but then it will always be
    at least slightly bulkier than could be achieved with a 4/3 sized sensor.
     
    dj_nme, Oct 11, 2008
    #4
  5. Guest

    Paul Furman Guest

    Not as long as larger sensors are exponentially more expensive.
    Probably just a matter of time before we see this. The current live view
    on DSLRs is awkward as heck, the mirror klunks up, then there's three
    clickety clacks when you shoot, and don't forget which mode you left it in!

    --
    Paul Furman
    www.edgehill.net
    www.baynatives.com

    all google groups messages filtered due to spam
     
    Paul Furman, Oct 11, 2008
    #5
  6. Guest

    Guest Guest

    | Perhaps "slightly increased image noise", rather than "reduced
    | resolution" due to a smaller sensor would be more accurate?
    | There are currently 4/3 DSLR cameras with the same or higher pixel count
    | (resolution) than similar price-ranged APS-c DSLR cameras, with no real
    | reason why this won't continue.

    Sure, if they are squeezing the pixels down smaller, then other conditions
    being equal, there will be more noise.

    Why smaller? Is it because so many people want a smaller lighter camera?
    It doesn't seem to be the good tool for dedicated photo hobbyists through
    to professionals. Maybe spies might like it, but I'm sure they have access
    to some really cool stuff that we could never afford even if it wasn't a
    secret. Still, there are laws of physics even spies can't get around.


    |> My goal would be to see a system
    |> with at least some cameras at full frame, and lenses that can cover it.
    |> That, in addition to the further details that has been added. Four-thirds
    |> would not satisfy my needs, and probably not that of many others, either.
    |
    | I believe that it depends on what your goal is, if it's the smallest
    | interchageable lens camera with a large sensor and affordable price,
    | then totally disregarding the Mu4/3 standard seems a tiny bit foolish to me.

    My goal isn't for a smallest system. It's for a good quality system (and
    that means to me a full-frame sensor) that can be compatible within reason
    to lower priced cameras (which likely means a smaller sensor).


    | The most attractive part of the Panasonic DMC-G1 is it's 1.4mp EVF,
    | although the "mini SLR" styling doesn't make the smallest it could be.
    | If the mock-up Mu4/3 that Olympus was displaying at FotoKina had that
    | EVF in the top left-hand corner on the back of the body, then I think it
    | would be a really great design.

    How would "top left-hand corner" be significant?


    | The problem with that is that if the LCD is articulated from the left
    | hand edge, then it would have to be smaller so as to not interfere with
    | the EVF, but it could be articulate on the top or bottom edge instead.
    | The same design features could just as easily be incorporated into a
    | body with a larger (APS-c or 35mm FF) sensor, but then it will always be
    | at least slightly bulkier than could be achieved with a 4/3 sized sensor.

    I think I really don't know what you are referring to with this "articulated"
    reference. Is this a "pop out" viewfinder like cheap camcorders have?

    Personally, I think going smaller is the wrong idea. I do understand people
    do want smaller cameras generally for more casual shooting. I'd rather see
    things go more in the direction of medium format. But there won't be much of
    a market there, at least any time soon. Ideally, I'd like to see my design
    go full-frame (the full 36mm x 24mm). Then a smaller standard for the masses
    could still let them use "big lenses" using an adaptor (possible because the
    smaller camera mounts closer to the sensor, defining the size of the adapter).

    As for LCDs, I'm thinking there should be 2 of them. One is on the inside
    and viewed through the traditional viewfinder when holding the camera up to
    your face. The other is on the back for more convenient use when the camera
    is on a tripod (a convenience I did not have with my Nikon FE-2 back when I
    did film).
     
    Guest, Oct 11, 2008
    #6
  7. Guest

    Guest Guest

    that's on nikon. canon does a much better job. the mirror stays up &
    sensor does a rolling first shutter curtain.
     
    Guest, Oct 11, 2008
    #7
  8. Guest

    dj_nme Guest

    If your idea isn't to design a smaller system camera, then why bother
    with mentioning a shorter mount-to-sensor distance or a viewfinder
    that's designed to save room (such as an EVF instead of an SLR viewfinder).
    You've lost me on want you're actually after.
    So why not just settle and get a Canon EOS DSLR?
    It has the shortest mount-to-sensor distance with a large sensor (both
    APS-c and 35mm FF) and can be adapted with mechanical rings to use most
    other lenses (except 4/3 and Leica RF).
    My guess is that most of your goal would be achieved with a 5D sensor
    put into a Rebel body, it would be very compact for a large-sensor DSLR
    camera.
    It would remove the need to squish your nose against the LCD when
    looking through the eyepiece, if it was placed centrally like on most
    cameras with a viewfinder.
    The reason why I suggest "top left-hand corner" for the EVF is so that
    there is no "hump" to accommodate it (like if it's located in the top
    middle) and so that there is space below it hinge the LCD from.
    You've never seen a digicam with an LCD which can fold out and twist around?
    That's what's called "articulated LCD": it isn't fixed in position to
    the back of the camera.
    I agree, this wouldn't make much sense.
    Considering that there are already several medium format DSLR cameras in
    the market and the volume of sale isn't very large.
    There is also now a new one, in the form of the Leica S2, to compete
    against.
    That's called an EVF (Electronic ViewFinder).
    I would suggest an articulated LCD, then you could angle it for easy
    viewing.
     
    dj_nme, Oct 11, 2008
    #8
  9. Guest

    Paul Furman Guest

    I haven't really looked into it, there's a couple different modes I
    think for AF, and I've not even tried it with AF lenses. Maybe it's
    dropping the mirror again to focus... ack I should change that!

    --
    Paul Furman
    www.edgehill.net
    www.baynatives.com

    all google groups messages filtered due to spam
     
    Paul Furman, Oct 11, 2008
    #9
  10. Guest

    dj_nme Guest

    I don't have either an EOS nor Nikon.
    According to dpreview.com, the Nikon D700 can use contrast detection
    when it live-view mode (described as "tripod mode") and that should keep
    the mirror in the up position.
    http://www.dpreview.com/reviews/nikond700/page2.asp
    Have a look under "Auto Focus", which is about a quarter of the way down
    the list of specifications.
     
    dj_nme, Oct 12, 2008
    #10
  11. Guest

    Guest Guest

    that's correct, but when you take the picture, the mirror drops, goes
    back up, the shutter fires and the mirror returns. on canon, the
    mirror stays up and the shutter fires (and it's a whole lot quieter
    too). also, the sensor does a rolling first curtain so the shutter
    doesn't close before taking the photo.
     
    Guest, Oct 12, 2008
    #11
  12. Guest

    dj_nme Guest

    So it's probably a slight tweak of this that has allowed Canon to
    squeeze video recording into the 5D Mark II, as a part of the live-view
    feature.
    Pretty clever really.
     
    dj_nme, Oct 12, 2008
    #12
  13. Guest

    Guest Guest

    video, which both nikon and canon now do, is basically just dump the
    live view stream to a memory card.
     
    Guest, Oct 12, 2008
    #13
  14. Also worth mentioning is the ingenious live view implementation on the
    Sony Alpha 300 & 350. That escapes from all this mirror nonsense, plus
    being able to retain fast phase-detection focussing in live view, by
    using a separate live view sensor which feeds off the optical
    viewfinder light path. In effect you switch the pentaprism between
    optical viewfinding or live view sensing. They also use all the pixels
    of that smaller live view sensor, when in operation, to do exposure
    metering, which gives very precise auto-exposure with no highlight
    loss.

    The LCD is also articulated. Most people talk of the advantage of that
    as being able to get a usable live view in an awkward place, such as
    held overhead or flat on the ground. Are most people here too young to
    have enjoyed waist and chest level composition with a twin lens
    reflex? While I find its use in awkward positions very useful, my most
    common use of live view is in TLR look-down mode. For a lot of
    portrait and interior work it gives a better perspective, and saves a
    lot of bended knee work.

    I'm not much of a fan of the usual simple live view panel in the back
    of the camera, since a good optical viewfinder is so much better. It's
    main utility is in reviewing photographs you've taken, which is handy
    for checking focus and exposure. An articulated live view, however, is
    a completely different animal. I find articulation of the live view
    LCD, backed up with a live view video output feed which can drive a
    remote monitor by wire or radio for even more diffcult camera
    placings, so very useful that I now wouldn't buy a DSLR (or any other
    digital camera) without it.
     
    Chris Malcolm, Oct 12, 2008
    #14
  15. Chris Malcolm wrote:
    []
    I like the idea of the articulated LCD as well - avoids situations like
    this one:

    http://www.satsignal.eu/2008-03-21-0858-50.jpg

    Cheers,
    David
     
    David J Taylor, Oct 12, 2008
    #15
  16. Guest

    Guest Guest

    it's clever, but since it's not the same sensor as the one that takes
    the picture, it is subject to alignment issues (and with two mirrors,
    not just one). that defeats one of the main advantages of live view.
    and video is going to be a whole lot trickier to do, if it's possible
    at all.
     
    Guest, Oct 12, 2008
    #16
  17. Guest

    Paul Furman Guest

    Here's some copy/paste from the pdf manual below. I don't see any way to
    make fewer clickety-clack sounds: first shutter press is one klunk, AF
    button may or may not drop the mirror depending on the mode, second
    shutter press always makes three clickety-clacks. Continuous shooting
    mode goes completely blank as you rattle off shots which is not very
    helpful! I don't claim to have this all figured out, if anyone
    understands better, please explain.

    *Live View Options*

    Hand-held (default)
    Choose when taking hand-held shots of moving
    subjects, or when framing photographs at angles that
    make it difficult to use the viewfinder (pg. 93). Camera
    focuses normally using phase-detection autofocus.

    Tripod
    Choose when the camera is mounted on a tripod. View
    can be enlarged in monitor for precise focus, making
    this mode suitable for static subjects (pg. 96). Autofocus
    can be used to compose photographs with subject
    positioned at any point in the frame without
    recomposing photograph. Camera focuses using
    contrast-detect autofocus.

    Phase-Detection Versus Contrast-Detect AF
    The camera normally uses phase-detection autofocus, in which focus is
    adjusted based on data from a special focusing sensor. When Tripod is
    selected in live view, however, the camera uses contrast-detect
    autofocus, in which the camera analyses the data from the image sensor
    and adjusts focus to produce the greatest contrast. Contrast-detect
    autofocus takes longer than phase-detection autofocus.


    *Hand-Held Mode*

    1 Select live view mode.
    Press the release mode dial
    lock release and turn the
    release mode dial to LV.

    2 Press the shutter-release
    button all the way down.
    The mirror will be raised and
    the view through the lens will
    be displayed in the camera
    monitor instead of the viewfinder (for improved focus, pause
    briefly with the shutter-release button pressed halfway before
    pressing it the rest of the way down). To exit without taking a
    picture, rotate the release mode dial to another setting or
    press MENU.

    3 Frame a picture in the monitor.
    To magnify the view in the monitor up to 13 ×, press the X
    button. While the view through the lens is zoomed in, a
    navigation window will appear in the bottom right
    corner of the display. Use the multi selector to scroll
    within the AF area brackets.

    4 Focus.
    Autofocus (focus mode S or C):
    Press the shutter-release button halfway or press the AF-ON button.

    [note: I've set the camera to AF only with the AF-ON button, this is not
    the default]

    The camera will focus normally and set exposure. Note that the mirror
    will click back into place while either button is pressed, temporarily
    interrupting live view. Live view is restored when the button is
    released. The focus point can be selected using the multi selector.
    Manual focus (focus mode M; pg. 81): Focus using the lens
    focusing ring. The focus point for electronic range finding can
    be selected using the multi selector.

    5 Take the picture.
    Press the shutter-release button the rest of the way down to reset focus
    and exposure and take the picture. If continuous high speed or
    continuous low speed is selected for Release mode, the monitor will turn
    off while the shutter-release button is pressed. The frame advance rate
    for continuous mode is the same as that selected for standard shooting.

    ! No Picture
    After shooting, play the picture back in the monitor to ensure that the
    photograph has been recorded. Note that the sound the mirror makes
    when the shutter-release button is pressed halfway or the B button is
    pressed can be mistaken for the sound of the shutter, and that pressing
    the shutter-release button all the way down when the camera is unable to
    focus in single-servo AF will end live view without a photograph being
    recorded.

    [note: I've set the camera to shoot whether in focus or not, this is not
    the default]

    *Tripod Mode*

    1 Ready the camera. Mount the camera on a tripod or place it on a
    stable, level surface.

    2 Select live view mode. Press the release mode dial
    lock release and turn the release mode dial to LV.

    3 Frame a picture in the viewfinder. Frame a picture in the viewfinder
    and select a focus point using the multi selector, then press the AF-ON
    button. The camera will focus normally and set exposure. Note that the
    camera can not be focused by pressing the shutter-release button halfway.

    [note: I've set the camera to AF only with the AF-ON button, this is not
    the default]

    4 Press the shutter-release button all the way down. The mirror will be
    raised and the view through the lens will be displayed in the camera
    monitor. The subject will no longer be visible in the viewfinder. To
    exit without taking a picture, rotate the release mode dial to another
    setting or press MENU.

    5 Check the view in the monitor. To magnify the view in the monitor up
    to 13 × and check focus, press the ZOOM button. While the view through
    the lens is zoomed in, a navigation window will appear in the bottom
    right corner of the display. Use the multi selector to scroll to areas
    of the frame not visible in the monitor. Press OK to exit zoom.

    Autofocus (focus mode S or C): In tripod mode, the focus point for
    contrast-detect autofocus can be moved to any point in the frame using
    the multi selector. To focus using contrast-detect autofocus, press the
    AF-ON button. The focus point will blink green and the monitor may
    brighten while the camera focuses. If the camera is able to focus using
    contrast-detect autofocus, the focus point will be displayed in green;
    if the camera is unable to focus, the focus point will blink red.

    Manual focus (focus mode M; pg. 81): Use zoom for precise focus.

    6 Take the picture.
    Press the shutter-release button the rest of the way
    down to take the picture. If continuous high speed
    or continuous low speed is selected for Release mode, the
    monitor will turn off while the shutter-release button is
    pressed. The frame advance rate for continuous mode is the
    same as that selected for standard shooting.

    Contrast-Detect Autofocus
    The camera will not continue to adjust focus while the AF-ON button is
    pressed in continuous-servo autofocus mode. In both single-servo and
    continuous-servo autofocus modes, the shutter can be released even
    when the camera is not in focus.

    Focusing with Contrast-Detect Autofocus
    Contrast-detect autofocus will take longer than normal (phase-detection)
    autofocus. In the following situations, the camera may be unable to focus
    using contrast-detect autofocus:
    • The camera is not mounted on a tripod
    • The subject contains lines parallel to the long edge of the frame
    • The subject lacks contrast
    • The subject in the focus point contains areas of sharply contrasting
    brightness, or the subject is lit by spot lighting or by a neon sign or
    other
    light source that changes in brightness
    • A cross (star) filter or other special filter is used
    • The subject appears smaller than the focus point
    • The subject is dominated by regular geometric patterns (e.g., windows
    in a skyscraper)
    • The subject is moving

    Note that the focus point may sometimes be displayed in green when the
    camera is unable to focus.

    Use an AF-S lens. The desired results may not be achieved with other
    lenses or teleconverters.

    [note: with a screw drive AF lens, the focus point does not turn green
    in hand held mode, it just drops the mirror & takes one stab at
    focusing. In tripod mode, I can hold down the AF-ON button and it will
    continue hunting; going green or red as it changes, even though I've got
    the AF mode switch on the body set to single. The whole experience is
    very confusing and counterintuitive]

    --
    Paul Furman
    www.edgehill.net
    www.baynatives.com

    all google groups messages filtered due to spam
     
    Paul Furman, Oct 12, 2008
    #17
  18. Guest

    dj_nme Guest

    Video with the Sony DSLR should be the same as with a P&S: record the
    live-view to memory card.
    At least doing it this way means that the live-view imaging sensor could
    be better tuned to video, as it's already providing a stream of video
    for the LCD.
     
    dj_nme, Oct 12, 2008
    #18
  19. Guest

    Bhogi Guest

    1.  The viewfinder that is normally viewing through the taking lens via a

    8. Tilt and shift lens mount.
     
    Bhogi, Oct 13, 2008
    #19
  20. Guest

    J. Clarke Guest

    Less useful than I expected in small format.
     
    J. Clarke, Oct 13, 2008
    #20
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