Are primes brighter and sharper than wide open zooms

Discussion in 'Digital SLR' started by Siddhartha Jain, Sep 28, 2005.

  1. Siddhartha Jain

    Eugene Guest

    Eugene, Sep 29, 2005
    #21
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  2. Siddhartha Jain

    Jeff R Guest

    Totally sick post, bro'! Hectic!
    What a gay idea!
     
    Jeff R, Sep 29, 2005
    #22
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  3. F/2.8 lets the same amount of light through regardless of the lens
    design. F/2.8 is f/2.8.

    Being from the old school, I would expect a fixed focal length lens to
    be sharper than a zoom, but you may have to go to laboratory conditions
    to prove it.
     
    Randall Ainsworth, Sep 29, 2005
    #23
  4. Siddhartha Jain

    Peter Guest

    No, but it can be good to distinguish between slang terminology
    and standard terminology.

    For instance, in audio people often talk about "acetate masters"
    when they mean "lacquer originals." The slang terminology is
    wrong on two counts because the originals of disc recordings
    are made on cellulose nitrate lacquer and never acetate and they
    are originals, not masters, according to long established terminology.
    The use of the slang "acetate master" has caused very little real
    confusion over the 70 years in which it has been in common use,
    but it is still not correct because the disc is neither made
    of acetate nor a master. (Wikipedia gets the definition of
    "master recording" wrong, so I don't think it is a very good
    source for standard technical vocabulary.)

    An example in photography is the use of the word "macro"
    as a synonym for "extreme close-up." Photomacrography,
    from which we get "macro," has a very well established
    technical meaning requiring the image size to be equal to
    or larger than the object size. The Wikipedia article
    "Macro Photography" starts out with the standard definition
    which it calls the "classical definition" and then goes
    on to discuss the extended use of the term in photographers'
    slang without being particularly clear that the extended
    meaning is still non-standard terminology. BTW it is better
    to use "photomacrography" than "macro photography" since
    "macrophotography" can mean the making of large photographs
    by analogy with the difference between "photomicrography"
    and "microphotography" which should never be confused with
    each other.

    The use of "prime lens" for "fixed focal length lens" appears
    to originate in cinema where the need for a handy term
    for a non-zoom lens was felt long before such a term was
    needed in still photography. As a handy bit of slang, it
    has much to recommend it: it is easy to say and quickly
    understood. As a technical term, it has two major difficulties:
    the word "prime" has little connection to what is meant,
    and there was a prior use of the term in which the word
    "prime" actually made sense.

    No, because you would always also be using an additional term
    such as "supplementary lens" or "teleconverter" which would
    supply the context which would make the meaning clear.

    You know, sometimes words have two meanings.

    Most of us can live with slang terminology and standard technical
    terminology without getting particularly confused. Slang terminology
    can be very handy: I'm not going to stop saying "Hypo" when I know
    that fixer is actually thiosulphate. It isn't very likely that someone
    will think I mean the actual chemical "sodium hyposulphite" AKA
    "sodium hydrosulphite" which is AFAIK not used in photography.
    But it is still good to distinguish between slang and proper technical
    language. If I ordered "sodium hyposulphite" from a chemical supplier
    who served dyers it is just possible I might get the wrong chemical.

    Peter.
     
    Peter, Sep 29, 2005
    #24
  5. Siddhartha Jain

    Peter Guest

    No, but it can be good to distinguish between slang terminology
    and standard terminology.

    For instance, in audio people often talk about "acetate masters"
    when they mean "lacquer originals." The slang terminology is
    wrong on two counts because the originals of disc recordings
    are made on cellulose nitrate lacquer and never acetate and they
    are originals, not masters, according to long established terminology.
    The use of the slang "acetate master" has caused very little real
    confusion over the 70 years in which it has been in common use,
    but it is still not correct because the disc is neither made
    of acetate nor a master. (Wikipedia gets the definition of
    "master recording" wrong, so I don't think it is a very good
    source for standard technical vocabulary.)

    An example in photography is the use of the word "macro"
    as a synonym for "extreme close-up." Photomacrography,
    from which we get "macro," has a very well established
    technical meaning requiring the image size to be equal to
    or larger than the object size. The Wikipedia article
    "Macro Photography" starts out with the standard definition
    which it calls the "classical definition" and then goes
    on to discuss the extended use of the term in photographers'
    slang without being particularly clear that the extended
    meaning is still non-standard terminology. BTW it is better
    to use "photomacrography" than "macro photography" since
    "macrophotography" can mean the making of large photographs
    by analogy with the difference between "photomicrography"
    and "microphotography" which should never be confused with
    each other.

    The use of "prime lens" for "fixed focal length lens" appears
    to originate in cinema where the need for a handy term
    for a non-zoom lens was felt long before such a term was
    needed in still photography. As a handy bit of slang, it
    has much to recommend it: it is easy to say and quickly
    understood. As a technical term, it has two major difficulties:
    the word "prime" has little connection to what is meant,
    and there was a prior use of the term in which the word
    "prime" actually made sense.

    No, because you would always also be using an additional term
    such as "supplementary lens" or "teleconverter" which would
    supply the context which would make the meaning clear.

    You know, sometimes words have two meanings.

    Most of us can live with slang terminology and standard technical
    terminology without getting particularly confused. Slang terminology
    can be very handy: I'm not going to stop saying "Hypo" when I know
    that fixer is actually thiosulphate. It isn't very likely that someone
    will think I mean the actual chemical "sodium hyposulphite" AKA
    "sodium hydrosulphite" which is AFAIK not used in photography.
    But it is still good to distinguish between slang and proper technical
    language. If I ordered "sodium hyposulphite" from a chemical supplier
    who served dyers it is just possible I might get the wrong chemical.

    Peter.
     
    Peter, Sep 29, 2005
    #25
  6. It's pretty much established jargon in the photo industry. I've seen it
    used in this sense since the mid-70s (when I started paying attention to
    photo stuff). I hardly think it can be blamed solely on the internet.
     
    Brion K. Lienhart, Sep 29, 2005
    #26
  7. Not to be pedantic, but I think you mean "Jargon" not "Slang".
     
    Brion K. Lienhart, Sep 29, 2005
    #27
  8. Well, no. The F-stop is the ratio of the aperature to the focal length,
    which is constant regardless of the actual material(s) of the glass. In
    the extreme case of spraying black paint on the lens, you could have an
    F:2.8 lens with 0% light transmission.
     
    Brion K. Lienhart, Sep 29, 2005
    #28
  9. Nope. F:2.8 is solely based on the size of the lens. Obsidian is glass,
    you can grind it into a lens shape, but if you use it as an element in a
    lens, you're going to get some reallllllly slow shutter speeds. Of
    course that's an extreme case, the difference between plain old glass
    glass, and exotic flouro-silicates is only a few fractions of a percent.
     
    Brion K. Lienhart, Sep 29, 2005
    #29
  10. Siddhartha Jain

    Eugene Guest

    I don't think it has anything to do with the internet really. They've
    been called prime lenses for as long as I can remember, and yes I do
    pre-date the Internet ;-)

    I certainly don't think it's some kind of fad. I suspect it would have
    originated about the same time as zoom lenses. People needed a handy
    term to distinguish their FFL lenses from the new zooms. FFL may be easy
    and quick to write, but 'prime' is quicker to say. Also if we're going
    to get pedantic about linguistics then why not take offence to the term
    "zoom lens". Surely they should be called Variable Focal Length Lenses,
    or VFL lenses. That's much better... Now we just have to re-educate all
    the millions of poor ignorant fools using the incorrect terminology ;-)
     
    Eugene, Sep 29, 2005
    #30
  11. Siddhartha Jain

    Eugene Guest

    OK, fair enough. You make a valid point, but in the case of "prime
    lens", given the definition of the word, I don't think it's nescessarily
    incorrect or ambiguous. Shortening complex expressions is just how
    language works. Just a few other slang photographic terms I could think
    of would be "film", or "sensor", or "flash", or even "lens". Everyone
    knows what these terms mean, although none of them is strictly correct
    or complete.
    Perhaps my comments were a bit harsh. I just took offense to the
    suggestion that it was ignorant to use the widely accepted and
    understood term "prime lens". It seemed clear that the Nostrobino was
    just being undully pedantic and argumentative, and his comments added
    nothing to the thread.
    As an Australian I certainly have no problem with slang ;-) Mind you
    when I'm writing things for an international audience I'm careful to
    avoid terms that will confuse people in other parts of the world. If I
    wrote the way I would typically talk to other Aussies then a lot of
    people wouldn't know what I was talking about. I hardly think though
    that "prime lens" is one of those confusing obscure slang expressions.
    Everyone knows what it means.
     
    Eugene, Sep 29, 2005
    #31
  12. Siddhartha Jain

    Tony Polson Guest


    If only it was as simple as referring to all fixed focal length lenses
    as "prime" lenses. Most subscribers to this newsgroup probably aren't
    old enough to recall that some manufacturers used the term "prime" to
    refer to a high quality subset of their fixed focal length lenses.

    What made a particular fixed focal length lens design a "prime" lens
    was not clear. Why other fixed focal length lenses were not described
    as "prime" lenses was even less clear. But what is clear is that
    assuming all fixed focal length lenses were referred to as "prime"
    lenses is wrong. It was marketing, pure and simple.

    Since there is no accepted definition of a "prime" lens we should just
    drop the term, as it serves only to confuse.

    I like the idea of FFL and VFL, especially as so many VFL optics are
    not true zooms because they do not hold focus when zoomed. They are
    often termed vari-focal lenses (also "VFL"), which term could be
    extended to include the true zooms.

    FFL and VFL has my vote.

    ;-)
     
    Tony Polson, Sep 29, 2005
    #32
  13. Siddhartha Jain

    Eugene Guest

    OK, I stand corrected. This does make sense. Actually now that I think
    about it I don't tend to use the terms "prime" and "zoom" much anyway.
    I'd nearly always just refer to the specific lens type. Like I'd just
    say 50mm f1.4 rather than 50mm prime. Adding "prime" is kind of
    redundant. If only one focal length lens is given then it's obvious I'm
    not talking about variable focal length.

    Also I think there would be very few situations where lumping everything
    into 2 distinct groups would make sense. For example "zoom" could
    equally refer to an EF-S 18-55, as it could to an EF 70-200 f2.8 L.
    Aside from the fact that both lenses can change focal lengths, they
    really have nothing much else in common. They serve entirely different
    purposes and an entirely different market. Likewise "prime" (meaning
    FFL) could equally refer to a 7mm circular fisheye, or a 1200mm
    super-telephoto.

    Grouping lenses by focal length ranges makes more sense, ultra-wide,
    wide-angle, medium-telephoto, super-telephoto etc. FFL and VFL, while
    correct and non-ambiguous are also I think too broad to be generally useful.

    OK, well I wont use the term "prime" or "zoom" anymore as I can see that
    they really don't add a lot of value.
     
    Eugene, Sep 29, 2005
    #33
  14. Siddhartha Jain

    Tony Polson Guest


    But "prime lens" is NOT a "widely accepted and understood term".

    Because of the history of its use, it is essentially ambiguous. It
    has only been used as a descriptor for all fixed focal length lenses
    in recent times, and only by people who are unaware of its prior
    usage, which was as a descriptor for a "high quality" subset of fixed
    focal length lenses. You might be too young to recall this.

    There was no accepted definition of which fixed focal length lenses
    were "prime" and which were not. It was merely an attempt by
    marketing people to promote some lenses as being "better" than others,
    the implication being that one brand was "better" than another because
    of the "high quality" of their "prime" lenses.

    The terms "high quality", "better" and "prime" are all essentially
    meaningless unless backed up with something more objective, repeatable
    and reliable. As we all (should) know, comparisons between lenses are
    qualitative at best.

    The most commonly used "objective" comparator - MTF - was never
    intended for making such comparisons. It was intended as an aid to
    lens designers and nothing more. As a result it misleads far more
    than it ever informs, and those who claim it is of any real value when
    comparing photographic lenses are suffering from delusions.
     
    Tony Polson, Sep 29, 2005
    #34
  15. Siddhartha Jain

    Chris Brown Guest

    Feel free to go ahead. The rest of the world will carry on using it. You're
    tilting at windmills.
     
    Chris Brown, Sep 29, 2005
    #35
  16. Siddhartha Jain

    kashe Guest

    So what was your point in bringing up a special case ulikely
    to be implemented?
     
    kashe, Sep 29, 2005
    #36
  17. Siddhartha Jain

    Jan Böhme Guest

    skrev:
    To illustrate the difference in principle between f-stop and t-stop in
    an obviuos way, perhaps?

    Jan Böhme
     
    Jan Böhme, Sep 29, 2005
    #37
  18. An f/2.8 lens is going to allow a specific amount of light to go
    through regardless of what kind of glass it's made of.
     
    Randall Ainsworth, Sep 29, 2005
    #38
  19. Siddhartha Jain

    no_name Guest

    Just because "popular usage" may not appear in a particular dictionary
    does not constitute "misuse".

    If you speak of a prime lens to photographers, they know what you're
    talking about.

    Perhaps this should be continued in rec.english.language.anal.purists
     
    no_name, Sep 29, 2005
    #39
  20. Siddhartha Jain

    no_name Guest

    Who here does not understand what is meant when the term "prime lens" is
    used?

    A show of hands please?
     
    no_name, Sep 29, 2005
    #40
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