F2.8 not equal F2.8 ?

Discussion in 'Digital Photography' started by Alfred Molon, Jan 17, 2004.

  1. Alfred Molon

    Alfred Molon Guest

    Is it true that different zoom lenses will let through different amounts
    of light because "...glass is not 100% transmissive, and that zooms use
    lots of elements, and that cheap prosumer glass isn't very high quality,
    and that coatings and finish and materials changes transmissivity..." ?

    In other would a cheap zoom lens opened at F2.8 let through the same
    amount of light as a better zoom lens at F3.5 for instance ?
    --

    Alfred Molon
    ------------------------------
    http://groups.yahoo.com/group/Olympus_405060/
    Olympus 5050 resource - http://www.molon.de/5050.html
    Olympus 5060 resource - http://www.molon.de/5060.html
    Alfred Molon, Jan 17, 2004
    #1
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  2. Alfred Molon

    ? Guest

    "Alfred Molon" <> wrote in message
    news:...
    > Is it true that different zoom lenses will let through different amounts
    > of light because "...glass is not 100% transmissive, and that zooms use
    > lots of elements, and that cheap prosumer glass isn't very high quality,
    > and that coatings and finish and materials changes transmissivity..." ?
    >
    > In other would a cheap zoom lens opened at F2.8 let through the same
    > amount of light as a better zoom lens at F3.5 for instance ?
    > --
    >
    > Alfred Molon
    > ------------------------------
    > http://groups.yahoo.com/group/Olympus_405060/
    > Olympus 5050 resource - http://www.molon.de/5050.html
    > Olympus 5060 resource - http://www.molon.de/5060.html


    All things being equal, and no missleading going on on the part of the lens
    maker f2.8 should represent f2.8 regardless of the transmissivity of the
    elements in the lens. In many cases with thru the lens metering there would
    not be a problem. But say and there are few examples any more aside from
    view cameras f x.x should be f x.x as such on each lens.
    But then take Sigma for example as well as Fuji with the pixel count on the
    imaging devices. I guess it all boils down like Clinton said it depends on
    what " if " means.
    The same can be said for shutters. If the exposure is calculated for a
    camera with a slow or fast shutter, or even the old mercury battery
    replacement being slightly under voltage the negative should come out OK.
    But in the case of extreemly slow or fast shutter you would be hard pressed
    to explain to someone how you froze the speeding auto at 1/30th.

    Just my thoughts about your question.
    ?, Jan 17, 2004
    #2
    1. Advertising

  3. > Is it true that different zoom lenses will let through different amounts
    > of light because "...glass is not 100% transmissive, and that zooms use
    > lots of elements, and that cheap prosumer glass isn't very high quality,
    > and that coatings and finish and materials changes transmissivity..." ?
    >
    > In other would a cheap zoom lens opened at F2.8 let through the same
    > amount of light as a better zoom lens at F3.5 for instance ?


    In principle, yes. The F number only says something about the physical
    dimensions of the lens, not its actual optical transmission.

    Dvid
    David J Taylor, Jan 17, 2004
    #3
  4. On 2004-01-17, David J Taylor <-this-bit> wrote:
    >> Is it true that different zoom lenses will let through different amounts
    >> of light because "...glass is not 100% transmissive, and that zooms use
    >> lots of elements, and that cheap prosumer glass isn't very high quality,
    >> and that coatings and finish and materials changes transmissivity..." ?
    >>
    >> In other would a cheap zoom lens opened at F2.8 let through the same
    >> amount of light as a better zoom lens at F3.5 for instance ?

    >
    > In principle, yes. The F number only says something about the physical
    > dimensions of the lens, not its actual optical transmission.


    I have been told that for camera equipment, the formulas for calculating
    the f-stop from dimensions is not valid, as f-stop in cameras are only
    related to light-transmission these days.

    Otherwise a lens with sunglass glass would always underexposure a picture.
    Povl H. Pedersen, Jan 17, 2004
    #4
  5. "?" <?@?.?> wrote in message
    news:Tb8Ob.25163$...
    >
    > "Alfred Molon" <> wrote in message
    > news:...
    > > Is it true that different zoom lenses will let through different amounts
    > > of light because "...glass is not 100% transmissive, and that zooms use
    > > lots of elements, and that cheap prosumer glass isn't very high quality,
    > > and that coatings and finish and materials changes transmissivity..." ?
    > >
    > > In other would a cheap zoom lens opened at F2.8 let through the same
    > > amount of light as a better zoom lens at F3.5 for instance ?
    > > --
    > >
    > > Alfred Molon
    > > ------------------------------
    > > http://groups.yahoo.com/group/Olympus_405060/
    > > Olympus 5050 resource - http://www.molon.de/5050.html
    > > Olympus 5060 resource - http://www.molon.de/5060.html

    >
    > All things being equal, and no missleading going on on the part of the

    lens
    > maker f2.8 should represent f2.8 regardless of the transmissivity of the
    > elements in the lens.


    Incorrect.

    All lenses vary in brightness at the same f-stop, from a marginal
    difference, to more than a stop. There's no way around it, rated f-stop is
    only the size of the opening, it has nothing to do with number or quality of
    lens elements, or basic lens design.

    Sigma's DG lenses (see http://sigma-photo.com/html/zoom_intro.htm) are a
    great example. They DG lenses are (quite intentionally) designed to be
    brighter at the same f-stop with digital sensors, because not only is the
    glassof extremely high quality, but the basic design is such that the rays
    are more parallel when exiting the rear element. Same basic thing
    microlenses are used for, to capture more of the angled rays at the sensor's
    periphery, but Sigma's DG line builds this characteristic into the lenses
    themselves. Put a the 24-70 EX DG and 28-70 EX (non-DG) on the same camera
    and set the same f-stop, the DG will be about a third stop brighter at the s
    ame aperture and focal length than the otherwise fabulous non-DG lens.

    The 24-70 EX DG is about a half stop brighter than the 24-70 HF at the same
    aperture and focal length - a reflection of the superb value HF's $85
    pricetag- even though the EX has 5 more elements, 14 vs. 9.

    In general, prosumer lenses are awful compared to even the cheapest D/SLR
    glass. The F707/717 would be one exception, on par with low to mid level
    D/SLR glass. But Fuji's f2.8 is not an exception, in fact the min ISO of
    160 shows that it is particularly dim. Though dimness is the least of
    prosumer lens problems, CA and barrel distortion are borderline absurd on
    most prosumers. Take a peek at cracker jack box Fuji optics...
    http://www.pbase.com/image/25203605/original

    Notice anything about those perfectly straight columns as they rise? Not to
    mention visible CA, even without backlighting. Then again, with all the
    SuperCCD Bayer interpolation artifacts littering the image, the lens hardly
    matters. It's hard to decide what ruins the image most.

    That's prosumer Fuji optics at 35mm equivalent, have a look at superior 25mm
    equivalent EX DG glass in front of 10.3MP...
    http://www.pbase.com/image/24323811/original

    Granted, the 15-30 EX DG alone costs about the same as the S602.

    > In many cases with thru the lens metering there would
    > not be a problem. But say and there are few examples any more aside from
    > view cameras f x.x should be f x.x as such on each lens.
    > But then take Sigma for example as well as Fuji with the pixel count on

    the
    > imaging devices. I guess it all boils down like Clinton said it depends on
    > what " if " means.
    > The same can be said for shutters. If the exposure is calculated for a
    > camera with a slow or fast shutter, or even the old mercury battery
    > replacement being slightly under voltage the negative should come out OK.
    > But in the case of extreemly slow or fast shutter you would be hard

    pressed
    > to explain to someone how you froze the speeding auto at 1/30th.
    >
    > Just my thoughts about your question.
    >
    >
    George Preddy, Jan 17, 2004
    #5
  6. "George Preddy" <> schrieb im Newsbeitrag
    news:bubb3r$e6b$...
    > In general, prosumer lenses are awful compared to even the cheapest D/SLR
    > glass. The F707/717 would be one exception, on par with low to mid level
    > D/SLR glass.


    If understand you correctly, a Minolta DiMAGE A1's zoom with F2,8 is no F2,8
    at least compared with a comparable 28-200/F2,8-3,5 zoom for a dSLR?
    Manfred Thaler, Jan 17, 2004
    #6
  7. "Manfred Thaler" <> wrote in message
    news:bube4q$7sk$01$-online.com...
    >
    > "George Preddy" <> schrieb im Newsbeitrag
    > news:bubb3r$e6b$...
    > > In general, prosumer lenses are awful compared to even the cheapest

    D/SLR
    > > glass. The F707/717 would be one exception, on par with low to mid

    level
    > > D/SLR glass.

    >
    > If understand you correctly, a Minolta DiMAGE A1's zoom with F2,8 is no

    F2,8
    > at least compared with a comparable 28-200/F2,8-3,5 zoom for a dSLR?


    You don't.
    George Preddy, Jan 17, 2004
    #7
  8. "George Preddy" <> wrote in message
    news:bubdpo$fcu$...
    >
    > "Manfred Thaler" <> wrote in message
    > news:bube4q$7sk$01$-online.com...
    > >
    > > "George Preddy" <> schrieb im Newsbeitrag
    > > news:bubb3r$e6b$...
    > > > In general, prosumer lenses are awful compared to even the cheapest

    > D/SLR
    > > > glass. The F707/717 would be one exception, on par with low to mid

    > level
    > > > D/SLR glass.

    > >
    > > If understand you correctly, a Minolta DiMAGE A1's zoom with F2,8 is no

    > F2,8
    > > at least compared with a comparable 28-200/F2,8-3,5 zoom for a dSLR?

    >
    > You don't.


    There is no way to know without comparing directly. A cheap lens might
    actually be brighter but with terrible other qualities, while a very
    expensive lens might be slightly dimmer with otherwise superb qualities. In
    general, the better the lens, the brighter the glass, but you cannot apply
    generalizations to specific lenses.

    Here is a good example, conditions are absolutely identical between images.
    Flip back and forth in medium thumbnail view, using the next/previous
    hyperlink to compare brightness. The image parameters and lens used is
    noted next at the bottom...

    http://www.pbase.com/imageprocessing/lenscompare

    SPP measures the difference at 0.3 stops.
    George Preddy, Jan 17, 2004
    #8
  9. George Preddy, Jan 17, 2004
    #9
  10. Alfred Molon

    Tony Spadaro Guest

    If the metering is done TTL - it matters not a whit. If you use a hand
    meter - you are probably within 1/6th of a stop of the actual transmission.
    In other words - don't sweat it. The only lenses that transmit seriously
    less light than the aperture claims are mirror lenses.

    --
    http://www.chapelhillnoir.com
    home of The Camera-ist's Manifesto
    The Improved Links Pages are at
    http://www.chapelhillnoir.com/links/mlinks00.html
    A sample chapter from my novel "Haight-Ashbury" is at
    http://www.chapelhillnoir.com/writ/hait/hatitl.html
    "Alfred Molon" <> wrote in message
    news:...
    > Is it true that different zoom lenses will let through different amounts
    > of light because "...glass is not 100% transmissive, and that zooms use
    > lots of elements, and that cheap prosumer glass isn't very high quality,
    > and that coatings and finish and materials changes transmissivity..." ?
    >
    > In other would a cheap zoom lens opened at F2.8 let through the same
    > amount of light as a better zoom lens at F3.5 for instance ?
    > --
    >
    > Alfred Molon
    > ------------------------------
    > http://groups.yahoo.com/group/Olympus_405060/
    > Olympus 5050 resource - http://www.molon.de/5050.html
    > Olympus 5060 resource - http://www.molon.de/5060.html
    Tony Spadaro, Jan 17, 2004
    #10
  11. Alfred Molon

    Tony Spadaro Guest

    This is a whole new package of codswollop from George - who is not named
    George, and may not even own a camera.

    --
    http://www.chapelhillnoir.com
    home of The Camera-ist's Manifesto
    The Improved Links Pages are at
    http://www.chapelhillnoir.com/links/mlinks00.html
    A sample chapter from my novel "Haight-Ashbury" is at
    http://www.chapelhillnoir.com/writ/hait/hatitl.html
    "George Preddy" <> wrote in message
    news:bubb3r$e6b$...
    >
    > "?" <?@?.?> wrote in message
    > news:Tb8Ob.25163$...
    > >
    > > "Alfred Molon" <> wrote in message
    > > news:...
    > > > Is it true that different zoom lenses will let through different

    amounts
    > > > of light because "...glass is not 100% transmissive, and that zooms

    use
    > > > lots of elements, and that cheap prosumer glass isn't very high

    quality,
    > > > and that coatings and finish and materials changes transmissivity..."

    ?
    > > >
    > > > In other would a cheap zoom lens opened at F2.8 let through the same
    > > > amount of light as a better zoom lens at F3.5 for instance ?
    > > > --
    > > >
    > > > Alfred Molon
    > > > ------------------------------
    > > > http://groups.yahoo.com/group/Olympus_405060/
    > > > Olympus 5050 resource - http://www.molon.de/5050.html
    > > > Olympus 5060 resource - http://www.molon.de/5060.html

    > >
    > > All things being equal, and no missleading going on on the part of the

    > lens
    > > maker f2.8 should represent f2.8 regardless of the transmissivity of the
    > > elements in the lens.

    >
    > Incorrect.
    >
    > All lenses vary in brightness at the same f-stop, from a marginal
    > difference, to more than a stop. There's no way around it, rated f-stop

    is
    > only the size of the opening, it has nothing to do with number or quality

    of
    > lens elements, or basic lens design.
    >
    > Sigma's DG lenses (see http://sigma-photo.com/html/zoom_intro.htm) are a
    > great example. They DG lenses are (quite intentionally) designed to be
    > brighter at the same f-stop with digital sensors, because not only is the
    > glassof extremely high quality, but the basic design is such that the rays
    > are more parallel when exiting the rear element. Same basic thing
    > microlenses are used for, to capture more of the angled rays at the

    sensor's
    > periphery, but Sigma's DG line builds this characteristic into the lenses
    > themselves. Put a the 24-70 EX DG and 28-70 EX (non-DG) on the same

    camera
    > and set the same f-stop, the DG will be about a third stop brighter at the

    s
    > ame aperture and focal length than the otherwise fabulous non-DG lens.
    >
    > The 24-70 EX DG is about a half stop brighter than the 24-70 HF at the

    same
    > aperture and focal length - a reflection of the superb value HF's $85
    > pricetag- even though the EX has 5 more elements, 14 vs. 9.
    >
    > In general, prosumer lenses are awful compared to even the cheapest D/SLR
    > glass. The F707/717 would be one exception, on par with low to mid level
    > D/SLR glass. But Fuji's f2.8 is not an exception, in fact the min ISO of
    > 160 shows that it is particularly dim. Though dimness is the least of
    > prosumer lens problems, CA and barrel distortion are borderline absurd on
    > most prosumers. Take a peek at cracker jack box Fuji optics...
    > http://www.pbase.com/image/25203605/original
    >
    > Notice anything about those perfectly straight columns as they rise? Not

    to
    > mention visible CA, even without backlighting. Then again, with all the
    > SuperCCD Bayer interpolation artifacts littering the image, the lens

    hardly
    > matters. It's hard to decide what ruins the image most.
    >
    > That's prosumer Fuji optics at 35mm equivalent, have a look at superior

    25mm
    > equivalent EX DG glass in front of 10.3MP...
    > http://www.pbase.com/image/24323811/original
    >
    > Granted, the 15-30 EX DG alone costs about the same as the S602.
    >
    > > In many cases with thru the lens metering there would
    > > not be a problem. But say and there are few examples any more aside from
    > > view cameras f x.x should be f x.x as such on each lens.
    > > But then take Sigma for example as well as Fuji with the pixel count on

    > the
    > > imaging devices. I guess it all boils down like Clinton said it depends

    on
    > > what " if " means.
    > > The same can be said for shutters. If the exposure is calculated for a
    > > camera with a slow or fast shutter, or even the old mercury battery
    > > replacement being slightly under voltage the negative should come out

    OK.
    > > But in the case of extreemly slow or fast shutter you would be hard

    > pressed
    > > to explain to someone how you froze the speeding auto at 1/30th.
    > >
    > > Just my thoughts about your question.
    > >
    > >

    >
    >
    Tony Spadaro, Jan 17, 2004
    #11
  12. Alfred Molon

    Mark M Guest

    <snip>

    > imaging devices. I guess it all boils down like Clinton said it depends

    on
    > > what " if " means.
    > > The same can be said for shutters. If the exposure is calculated for a
    > > camera with a slow or fast shutter, or even the old mercury battery
    > > replacement being slightly under voltage the negative should come out

    OK.
    > > But in the case of extreemly slow or fast shutter you would be hard

    > pressed
    > > to explain to someone how you froze the speeding auto at 1/30th.
    > >
    > > Just my thoughts about your question.


    I've never heard so much fancy jargon from someone who is ultimately full of
    crap.
    George is truly a sweet-talking idiot.
    Mark M, Jan 17, 2004
    #12
  13. Alfred Molon

    George Guest

    "?" <?@?.?> wrote in message
    news:Tb8Ob.25163$...
    >
    > "Alfred Molon" <> wrote in message
    > news:...
    > > Is it true that different zoom lenses will let through different amounts
    > > of light because "...glass is not 100% transmissive, and that zooms use
    > > lots of elements, and that cheap prosumer glass isn't very high quality,
    > > and that coatings and finish and materials changes transmissivity..." ?
    > >
    > > In other would a cheap zoom lens opened at F2.8 let through the same
    > > amount of light as a better zoom lens at F3.5 for instance ?
    > > --
    > >
    > > Alfred Molon
    > > ------------------------------
    > > http://groups.yahoo.com/group/Olympus_405060/
    > > Olympus 5050 resource - http://www.molon.de/5050.html
    > > Olympus 5060 resource - http://www.molon.de/5060.html

    >
    > All things being equal, and no missleading going on on the part of the

    lens
    > maker f2.8 should represent f2.8 regardless of the transmissivity of the
    > elements in the lens.


    Technically true as F stops are ratios of aperture SIZE to focal length of
    lens. However, the poster was asking about light transmission which is T
    stops (in reality) and DO depend on how much light is transmitted through
    the glass as well.
    George, Jan 18, 2004
    #13
  14. "Tony Spadaro" <> wrote in message
    news:elfOb.21499$...
    > If the metering is done TTL - it matters not a whit.


    Right, lens brightness doesn't matter at all because metering takes care of
    everything. Just use a 2 second shutter, it doesn't matter. Brightness is
    overrated.

    That makes no sense at all.
    George Preddy, Jan 18, 2004
    #14
  15. "Tony Spadaro" <> wrote in message
    news:1mfOb.21504$...
    > This is a whole new package of codswollop from George - who is not named
    > George, and may not even own a camera.


    Now you know.

    > http://www.chapelhillnoir.com
    > home of The Camera-ist's Manifesto
    > The Improved Links Pages are at
    > http://www.chapelhillnoir.com/links/mlinks00.html
    > A sample chapter from my novel "Haight-Ashbury" is at
    > http://www.chapelhillnoir.com/writ/hait/hatitl.html
    > "George Preddy" <> wrote in message
    > news:bubb3r$e6b$...
    > >
    > > "?" <?@?.?> wrote in message
    > > news:Tb8Ob.25163$...
    > > >
    > > > "Alfred Molon" <> wrote in message
    > > > news:...
    > > > > Is it true that different zoom lenses will let through different

    > amounts
    > > > > of light because "...glass is not 100% transmissive, and that zooms

    > use
    > > > > lots of elements, and that cheap prosumer glass isn't very high

    > quality,
    > > > > and that coatings and finish and materials changes

    transmissivity..."
    > ?
    > > > >
    > > > > In other would a cheap zoom lens opened at F2.8 let through the same
    > > > > amount of light as a better zoom lens at F3.5 for instance ?
    > > > > --
    > > > >
    > > > > Alfred Molon
    > > > > ------------------------------
    > > > > http://groups.yahoo.com/group/Olympus_405060/
    > > > > Olympus 5050 resource - http://www.molon.de/5050.html
    > > > > Olympus 5060 resource - http://www.molon.de/5060.html
    > > >
    > > > All things being equal, and no missleading going on on the part of the

    > > lens
    > > > maker f2.8 should represent f2.8 regardless of the transmissivity of

    the
    > > > elements in the lens.

    > >
    > > Incorrect.
    > >
    > > All lenses vary in brightness at the same f-stop, from a marginal
    > > difference, to more than a stop. There's no way around it, rated f-stop

    > is
    > > only the size of the opening, it has nothing to do with number or

    quality
    > of
    > > lens elements, or basic lens design.
    > >
    > > Sigma's DG lenses (see http://sigma-photo.com/html/zoom_intro.htm) are a
    > > great example. They DG lenses are (quite intentionally) designed to be
    > > brighter at the same f-stop with digital sensors, because not only is

    the
    > > glassof extremely high quality, but the basic design is such that the

    rays
    > > are more parallel when exiting the rear element. Same basic thing
    > > microlenses are used for, to capture more of the angled rays at the

    > sensor's
    > > periphery, but Sigma's DG line builds this characteristic into the

    lenses
    > > themselves. Put a the 24-70 EX DG and 28-70 EX (non-DG) on the same

    > camera
    > > and set the same f-stop, the DG will be about a third stop brighter at

    the
    > s
    > > ame aperture and focal length than the otherwise fabulous non-DG lens.
    > >
    > > The 24-70 EX DG is about a half stop brighter than the 24-70 HF at the

    > same
    > > aperture and focal length - a reflection of the superb value HF's $85
    > > pricetag- even though the EX has 5 more elements, 14 vs. 9.
    > >
    > > In general, prosumer lenses are awful compared to even the cheapest

    D/SLR
    > > glass. The F707/717 would be one exception, on par with low to mid

    level
    > > D/SLR glass. But Fuji's f2.8 is not an exception, in fact the min ISO

    of
    > > 160 shows that it is particularly dim. Though dimness is the least of
    > > prosumer lens problems, CA and barrel distortion are borderline absurd

    on
    > > most prosumers. Take a peek at cracker jack box Fuji optics...
    > > http://www.pbase.com/image/25203605/original
    > >
    > > Notice anything about those perfectly straight columns as they rise?

    Not
    > to
    > > mention visible CA, even without backlighting. Then again, with all the
    > > SuperCCD Bayer interpolation artifacts littering the image, the lens

    > hardly
    > > matters. It's hard to decide what ruins the image most.
    > >
    > > That's prosumer Fuji optics at 35mm equivalent, have a look at superior

    > 25mm
    > > equivalent EX DG glass in front of 10.3MP...
    > > http://www.pbase.com/image/24323811/original
    > >
    > > Granted, the 15-30 EX DG alone costs about the same as the S602.
    > >
    > > > In many cases with thru the lens metering there would
    > > > not be a problem. But say and there are few examples any more aside

    from
    > > > view cameras f x.x should be f x.x as such on each lens.
    > > > But then take Sigma for example as well as Fuji with the pixel count

    on
    > > the
    > > > imaging devices. I guess it all boils down like Clinton said it

    depends
    > on
    > > > what " if " means.
    > > > The same can be said for shutters. If the exposure is calculated for a
    > > > camera with a slow or fast shutter, or even the old mercury battery
    > > > replacement being slightly under voltage the negative should come out

    > OK.
    > > > But in the case of extreemly slow or fast shutter you would be hard

    > > pressed
    > > > to explain to someone how you froze the speeding auto at 1/30th.
    > > >
    > > > Just my thoughts about your question.
    > > >
    > > >

    > >
    > >

    >
    >
    George Preddy, Jan 18, 2004
    #15
  16. Alfred Molon

    Tony Spadaro Guest

    Ahh citizen Putz speaks again. Even Sigma does not claim their lenses
    transmit more light - and in fact, they don't. Why are you so determined to
    be suck a frickin' bad liar?
    --
    http://www.chapelhillnoir.com
    home of The Camera-ist's Manifesto
    The Improved Links Pages are at
    http://www.chapelhillnoir.com/links/mlinks00.html
    A sample chapter from my novel "Haight-Ashbury" is at
    http://www.chapelhillnoir.com/writ/hait/hatitl.html
    "George Preddy" <> wrote in message
    news:bucm53$62h$...
    > "Tony Spadaro" <> wrote in message
    > news:elfOb.21499$...
    > > If the metering is done TTL - it matters not a whit.

    >
    > Right, lens brightness doesn't matter at all because metering takes care

    of
    > everything. Just use a 2 second shutter, it doesn't matter. Brightness

    is
    > overrated.
    >
    > That makes no sense at all.
    >
    >
    Tony Spadaro, Jan 18, 2004
    #16
  17. "Tony Spadaro" <> wrote in message
    news:MfmOb.239692$...
    > Ahh citizen Putz speaks again.


    Is that supposed to help your statement that lens brightness doesn't matter?
    George Preddy, Jan 18, 2004
    #17
  18. Alfred Molon

    cwvalle Guest

    That is pure junk
    if the lens says it's f2.8 that's what it is...
    If that were not true
    automatic flash units, studio lights, and hand held light meters could not
    be used
    but they obviously can
    That's because f2.8 is f2.8 no matter what camera they are on
    and no matter who made them

    Carl


    "George Preddy" <> wrote in message
    news:bucqi8$87a$...
    >
    > "Tony Spadaro" <> wrote in message
    > news:MfmOb.239692$...
    > > Ahh citizen Putz speaks again.

    >
    > Is that supposed to help your statement that lens brightness doesn't

    matter?
    >
    >
    cwvalle, Jan 18, 2004
    #18
  19. Alfred Molon

    Tony Spadaro Guest

    I said nothing about lens brightness - the subject whenever you show up is
    your dimness. Since even Sigma doesn't claim any increased light
    transmission with their lenses I have to assume you are on another one of
    your little fugues again. Why don't you take it to a psych clinic George,
    they enjoy listening to strange stories from people who think they are long
    dead pilots.

    --
    http://www.chapelhillnoir.com
    home of The Camera-ist's Manifesto
    The Improved Links Pages are at
    http://www.chapelhillnoir.com/links/mlinks00.html
    A sample chapter from my novel "Haight-Ashbury" is at
    http://www.chapelhillnoir.com/writ/hait/hatitl.html
    "George Preddy" <> wrote in message
    news:bucqi8$87a$...
    >
    > "Tony Spadaro" <> wrote in message
    > news:MfmOb.239692$...
    > > Ahh citizen Putz speaks again.

    >
    > Is that supposed to help your statement that lens brightness doesn't

    matter?
    >
    >
    Tony Spadaro, Jan 18, 2004
    #19
  20. Alfred Molon

    Tony Spadaro Guest

    There can indeed be a small difference in actual light transmission. But
    George is, as usual, so full of sh-tuff his eyes are brown.

    --
    http://www.chapelhillnoir.com
    home of The Camera-ist's Manifesto
    The Improved Links Pages are at
    http://www.chapelhillnoir.com/links/mlinks00.html
    A sample chapter from my novel "Haight-Ashbury" is at
    http://www.chapelhillnoir.com/writ/hait/hatitl.html
    "cwvalle" <> wrote in message
    news:IgpOb.6789$...
    > That is pure junk
    > if the lens says it's f2.8 that's what it is...
    > If that were not true
    > automatic flash units, studio lights, and hand held light meters could not
    > be used
    > but they obviously can
    > That's because f2.8 is f2.8 no matter what camera they are on
    > and no matter who made them
    >
    > Carl
    >
    >
    > "George Preddy" <> wrote in message
    > news:bucqi8$87a$...
    > >
    > > "Tony Spadaro" <> wrote in message
    > > news:MfmOb.239692$...
    > > > Ahh citizen Putz speaks again.

    > >
    > > Is that supposed to help your statement that lens brightness doesn't

    > matter?
    > >
    > >

    >
    >
    Tony Spadaro, Jan 18, 2004
    #20
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