4/3 vs APS vs 35mm Full Frame Sensors

Discussion in 'Digital Photography' started by R2D2, Feb 14, 2004.

  1. R2D2

    Greg Dearing Guest

    Cokin P! :)
     
    Greg Dearing, Feb 17, 2004
    #41
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  2. According to what I've read, lenses can be telecentric in object space
    or in image space One that's telecentric in object space gives
    constant magnification as subject distance is changed. One that's
    telecentric in image space does not change magnification as image
    distance is changed, but magnification can still depend on image
    distance.

    But a fully telecentric design is slow, and requires a front or rear
    element that is larger than the diagonal of the object or image
    respectively. So the E-1 lenses are probably "somewhat telecentric".

    Dave
     
    Dave Martindale, Feb 17, 2004
    #42
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  3. I'll bet (a beer, payable in Tokyo) that none of the Olympus E-1 lenses are
    anything other than generic lenses. I doubt that you can either define what
    "somewhat telecentric" means or show that the E-1 lenses are anything other
    than (probably quite good) generic lenses.

    David J. Littleboy

    Tokyo, Japan
     
    David J. Littleboy, Feb 17, 2004
    #43
  4. You're right. I meant to write "can still depend on object distance".
    The point of such a lens is that magnification doesn't change as you
    adjust focus, but magnification *does* change as you adjust lens to
    subject distance.

    This can help in setting up an image copying device like an optical
    printer. With a conventional lens operating at near 1:1, it can be
    maddeningly difficult to get the image exactly the size you want and
    also in focus, since the slightest change in object or image distance
    changes both magnification and focus simultaneously. With a lens
    that's telecentric in one space, you adjust magnification with one
    movement (on the non-telecentric side) and then you can focus without
    changing magnification on the telecentric side of the lens.
    Perhaps not. The anecdote above suggests a way to tell: If you look
    through the SLR viewfinder and turn the focus ring back and forth,
    the image will go in and out of focus. If it *also* appears to change
    magnification at the same time, the lens is not telecentric in image
    space, which is where the publicity implies it will be.

    Dave
     
    Dave Martindale, Feb 17, 2004
    #44
  5. R2D2

    John Navas Guest

    [POSTED TO rec.photo.digital - REPLY ON USENET PLEASE]

    In <c0ruvm$7d2$> on Tue, 17 Feb 2004 11:42:48 +0900, "David J.
    Nonetheless many (most?) in the industry seem to be comfortable with it.
    And many other folks.
    That's not what I'm seeing in reviews. The E-1 does seem to have more noise
    at ISO 800 and up, but not below that point, and the big E-1 lenses are faster
    than the competition in any event -- see
    Expensive lenses needed for good results.
    Higher noise at low ISO than D60.
    Lateral chromatic aberration.
    Some moiré.
    Relatively slow flash sync.
    Likewise the 300mm f/2.8 telephoto.
    I don't agree -- see above.
     
    John Navas, Feb 17, 2004
    #45
  6. R2D2

    John Navas Guest

    [POSTED TO rec.photo.digital - REPLY ON USENET PLEASE]

    In <c0smm4$9j3$> on Tue, 17 Feb 2004 18:07:13 +0900, "David J.
    This claimed point of the 4/3 system is that light rays will strike the sensor
    at lower angles than with conventional lenses, based on 4/3 lens designs which
    take advantage of the relatively high 2x ratio of lens mount diameter to
    sensor size. (Only Canon lenses designed for digital can come close to this
    ratio.)
     
    John Navas, Feb 17, 2004
    #46
  7. R2D2

    John Navas Guest

    [POSTED TO rec.photo.digital - REPLY ON USENET PLEASE]

    As my cite noted, there is "no commonly accepted meaning" -- yours is just one
    of several differing points of view.
    Google rankings are based on criteria that don't confer authoritativeness.
    That's a personal website, with a definition taken from the Debian Free
    Software Guidelines, and thus reflects only a particular point of view.
    It nonetheless meets some other definitions.
    My guess is that Olympus probably wanted a period of exclusivity.
    The E-1 is still very new to the market.
    But nonetheless advantages.
    Nonetheless Olympus E-1 lenses are remarkable for small size and high speed.
    In this case it would seem that the standard is "open" to other companies that
    join the standards group.
     
    John Navas, Feb 17, 2004
    #47
  8. R2D2

    local Guest

    I will stick to either 1/1.8" or 35mm and ignore 4/3, APS, medium format,
    ....

    1/1.8" CCD and lens of 10mm focal length are developed by Zeiss and Sony.
    35mm films and lens of 50mm focal length are developed by Zeiss and Kodak.
     
    local, Feb 18, 2004
    #48
  9. R2D2

    Greg Dearing Guest

    Your own citation offered four definitions, and rejected as
    "all-too-broad" the only one that could possibly apply to Olympus.
    This from a web services "e-zine". :) It also seems to assume (quite
    naturally) that the specification is available for review, which
    FourThirds isn't.
    Any definition that includes FourThirds has been watered down to the
    point where it's meaningless anyway. Every business shares
    information with its partners.
    Gotta love open standards where one company dictates what other "group
    members" get to do with it.
    Why are the Canon and Nikon 300mm/f2.8 lenses are significantly
    lighter, smaller, cheaper, faster focusing and quieter than the
    Olympus 300/f2.8? The Canon is also image stabilized, a feature not
    available for the Olympus lineup.

    There are advantages to having a smaller sensor, which are even more
    pronounced in the P&S digicams, but Olympus' first efforts have been
    less than stunning.
    I see... business information shared with selected partners under NDA
    constitues an "open standard"? By this definition, the Nikon mount is
    just as open and the Pentax mount is considerably more so.


    Now that I understand your definition of open standard, perhaps you
    should give us your definition of profound. :)

    -Greg
     
    Greg Dearing, Feb 19, 2004
    #49
  10. R2D2

    John Navas Guest

    [POSTED TO rec.photo.digital - REPLY ON USENET PLEASE]

    While it's not published to anyone and everyone, it does seem to be available
    to participants and qualified prospects. Given the highly competitive nature
    of the industry, that doesn't seem unreasonable to me. (YMMV.)
    There are of course enormous differences in how information is shared, and how
    much information is shared.
    Nonetheless, that's not uncommon, and I don't think it's unreasonable.
    A more meaningful comparison that takes into consideration focal length
    differences:

    Zuiko Digital 300mm f/2.8
    3.3kg
    129mm wide
    281mm long
    B&H price US$6,500

    AF-S Nikkor 400mm f/2.8
    4.8kg
    max dia 160mm
    352mm long
    B&H price US$7,700

    Advantage E-1.
    Whereas I think it's pretty impressive.
    I disagree. See below.
    "of deep meaning; of great and broadly inclusive significance"
    [Random House Unabridged Dictionary]

    In this case, it's the potential to mix and match bodies as well as lenses
    from different manufacturers.
     
    John Navas, Feb 19, 2004
    #50
  11. R2D2

    Greg Dearing Guest

    I was hoping you'd say that...it's exactly the excuse Oly uses to
    overprice their lenses. The fact that there is a tiny sensor *behind*
    the lens doesn't excuse shortcomings in the lens itself.

    Canon Telephoto EF 300mm f/2.8 USM Image Stabilizer
    2.5kg
    128mm wide
    252mm long
    B&H price US$3,895

    If Canon released a body using a 4/3 sized sensor, their 300mm lens
    wouldn't suddenly cost $2600 more, weigh 33% more, and lose USM and
    IS. Olympus clearly could have done better, and didn't.
    They are, if you think the Sony F828 (effective 28-200mm/f2.0) should
    cost $30,000 and weigh 10 pounds. Somehow, it costs $1,000 and weighs
    2 lbs...with body attached!
    This is already common with both the Pentax and Nikon mounts. And,
    unlike either Nikon or Oly, the Pentax mount is actually open.

    -Greg
     
    Greg Dearing, Feb 20, 2004
    #51
  12. R2D2

    John Navas Guest

    [POSTED TO rec.photo.digital - REPLY ON USENET PLEASE]

    If you don't like the price, then don't buy it.
    Shortcomings? By all accounts it's an excellent lens.
    Inapposite focal length. Try Canon EF 400 mm f/2.8L IS USM.
     
    John Navas, Feb 20, 2004
    #52
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