What make a lens normal ?

Discussion in 'Digital Photography' started by Guest, Oct 22, 2006.

  1. Guest

    Guest Guest

    I'm back with more silly / newbie questions...

    In the 24 x 36 mm world, a normal lens is 50mm, normal because it offers the
    same angle of vision as the human eye. Now, this might be an error, my
    understanding is that at the equivalent quality, a normal lens is cheaper to
    make than either a wide angle and/or a telephoto lens. At the same time,
    it is possible to make normal lenses faster than any other type of lenses.

    My assumption here is because with the normal lenses you don't have to bend
    the light at weird angles the way it's done with wide an tele lenses. True /
    false ?

    Now here is the real question. With the 15 x 23 mm (aps-c) sensors, normal
    is 33mm. Right ?

    So, are we going to see cheap 33 mm lens, and faster than what we see
    today ?


    Thanks.
    Guest, Oct 22, 2006
    #1
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  2. wrote:
    > I'm back with more silly / newbie questions...
    >
    > In the 24 x 36 mm world, a normal lens is 50mm, normal because it
    > offers the same angle of vision as the human eye. Now, this might be
    > an error, my understanding is that at the equivalent quality, a
    > normal lens is cheaper to make than either a wide angle and/or a
    > telephoto lens. At the same time,
    > it is possible to make normal lenses faster than any other type of
    > lenses.
    >
    > My assumption here is because with the normal lenses you don't have
    > to bend the light at weird angles the way it's done with wide an tele
    > lenses. True / false ?
    >
    > Now here is the real question. With the 15 x 23 mm (aps-c) sensors,
    > normal is 33mm. Right ?
    >
    > So, are we going to see cheap 33 mm lens, and faster than what we see
    > today ?
    >
    >
    > Thanks.


    No. Nearly all lenses today for digital cameras are zooms. That is
    what the public wants and buys. You may start to find prime single focal
    length lenses in the normal lens for digitals, and some faster, but chances
    are the price will be more because the volume will be much less. The real
    reason that the "normal" lenses were cheap was because they made so many of
    them.

    --
    Joseph Meehan

    Dia duit
    Joseph Meehan, Oct 22, 2006
    #2
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  3. Guest

    Paul Rubin Guest

    <> writes:
    > Now here is the real question. With the 15 x 23 mm (aps-c) sensors, normal
    > is 33mm. Right ?
    >
    > So, are we going to see cheap 33 mm lens, and faster than what we see
    > today ?


    I think it's difficult because the lens mount to film plane distance
    is still the same as with a full frame SLR. So the 33mm lens has to
    be built something like a full frame SLR wideangle and not like a
    normal lens. I'd also say the absence of a 33mm-ish macro lens is
    even more annoying than the situation with normal lenses. There are
    good 35/2 and 35/1.4 lenses available if you want to pay for them.
    But there's no good flat-field macro lens in that focal length.

    IMO, these APS-C DSLR's using 35mm SLR lenses are something of a
    stopgap because full frame sensors are still quite expensive. But I
    think that will improve over the next year or two. After rebates an
    EOS-5D is just a little over $2K, which is not much over what the
    Nikon D100 (maybe the first more-or-less consumer DSLR) cost when it
    came out.

    Remember that Nikon's early DSLR's, the E2 and E3, cost over $10K each
    and used 2/3", 1.3 megapixel sensors or thereabouts. I hope Nikon
    will release some full frame models at PMA 2007, initially including a
    D300 at today's D200 price level. Once there is competition for the
    5D, these cameras should soon reach the D80 price level. Then you'll
    be able to use your 50mm normal and macro lenses.
    Paul Rubin, Oct 22, 2006
    #3
  4. Guest

    Scott W Guest

    wrote:
    > I'm back with more silly / newbie questions...
    >
    > In the 24 x 36 mm world, a normal lens is 50mm, normal because it offers the
    > same angle of vision as the human eye. Now, this might be an error, my
    > understanding is that at the equivalent quality, a normal lens is cheaper to
    > make than either a wide angle and/or a telephoto lens. At the same time,
    > it is possible to make normal lenses faster than any other type of lenses.
    >
    > My assumption here is because with the normal lenses you don't have to bend
    > the light at weird angles the way it's done with wide an tele lenses. True /
    > false ?

    Sort of, less bending then a wide angle lens and smaller elements then
    a telephoto lens. There is a sweet spot when lenses are the cheapest
    to make and still be fast and that would seem to be right around 50mm
    for a FF camera.

    For those how have not had the joy of trying to design a wide angle
    lens you can't make one without some pretty short radius surfaces and
    this dictates some pretty tight tolerances in alignment between the
    elements. You also need more elements for a wide angle lens.

    > Now here is the real question. With the 15 x 23 mm (aps-c) sensors, normal
    > is 33mm. Right ?
    >
    > So, are we going to see cheap 33 mm lens, and faster than what we see
    > today ?

    Well getting any lens faster then about 1.2 if pretty hard no matter
    how short the FL is. But I would like to see some f/1.4 shorter lenses
    that only work with the smaller sensors. If you only have an image
    circle large enough for the small sensors the lens should be cheap to
    produce.

    Scott
    Scott W, Oct 22, 2006
    #4
  5. Guest

    Charles Guest

    On 21 Oct 2006 18:14:23 -0700, "Scott W" <> wrote:

    > wrote:
    >> I'm back with more silly / newbie questions...
    >>
    >> In the 24 x 36 mm world, a normal lens is 50mm, normal because it offers the
    >> same angle of vision as the human eye. Now, this might be an error, my
    >> understanding is that at the equivalent quality, a normal lens is cheaper to
    >> make than either a wide angle and/or a telephoto lens. At the same time,
    >> it is possible to make normal lenses faster than any other type of lenses.
    >>
    >> My assumption here is because with the normal lenses you don't have to bend
    >> the light at weird angles the way it's done with wide an tele lenses. True /
    >> false ?

    >Sort of, less bending then a wide angle lens and smaller elements then
    >a telephoto lens. There is a sweet spot when lenses are the cheapest
    >to make and still be fast and that would seem to be right around 50mm
    >for a FF camera.
    >
    >For those how have not had the joy of trying to design a wide angle
    >lens you can't make one without some pretty short radius surfaces and
    >this dictates some pretty tight tolerances in alignment between the
    >elements. You also need more elements for a wide angle lens.
    >
    >> Now here is the real question. With the 15 x 23 mm (aps-c) sensors, normal
    >> is 33mm. Right ?
    >>
    >> So, are we going to see cheap 33 mm lens, and faster than what we see
    >> today ?

    >Well getting any lens faster then about 1.2 if pretty hard no matter
    >how short the FL is. But I would like to see some f/1.4 shorter lenses
    >that only work with the smaller sensors. If you only have an image
    >circle large enough for the small sensors the lens should be cheap to
    >produce.
    >
    >Scott



    I wondered about the 135 MM lenses for full frame 35 mm film, it used
    to seem to me they were quite inexpensive relative to other focal
    lengths.
    Charles, Oct 22, 2006
    #5
  6. <> wrote:
    > I'm back with more silly / newbie questions...
    >
    > In the 24 x 36 mm world, a normal lens is 50mm, normal because it offers
    > the
    > same angle of vision as the human eye.


    The "normal" lens offers neither the wide angle capability of the human eye
    (looking straight ahead, one's peripheral FOV is much closer to what a 20mm
    lens sees) nor the narrow angle of the central section where our vision is
    the sharpest.

    It looks to me that "normal" is a FOV that is easy to create optically
    (anything wider would be difficult with the three (or fewer) element lenses
    used in early P&S cameras) and not too long to be inconvenient (anything
    longer would make the (what is now medium format) P&S cameras that appeared
    starting in 1900 be bulkier than would be convenient.

    FWIW, Canon's three simplest lenses are the 50/1.8 (6 elements), 35/2.0 (7
    elements), and 90/2.8 TSE (6 elements).

    > Now, this might be an error, my
    > understanding is that at the equivalent quality, a normal lens is cheaper
    > to
    > make than either a wide angle and/or a telephoto lens. At the same time,
    > it is possible to make normal lenses faster than any other type of lenses.


    From looking at MTF curves, my impression is that 50mm lenses fall into the
    "wide angle" camp. This is because pretty much all lenses longer than normal
    (e.g. the 100/3.5 Hasselblad lens, the 110/2.8 Mamiya (both of which are
    only slightly longer than normal), and all the Canon/Nikon primes 85mm and
    over) retain excellent sharpness right out to the corners, whereas pretty
    much every lens normal to shorter (including the Hassy 80/2.8) shows
    significantly reduced contrast at the corners.

    > My assumption here is because with the normal lenses you don't have to
    > bend
    > the light at weird angles the way it's done with wide an tele lenses. True
    > /
    > false ?


    Longer lenses have a much easier time of it. They're physically larger, and
    thus more expensive.

    Also, until recently, the normal lenses were produced in vast quantities
    compared to any other lens, and thus were cheaper.

    > Now here is the real question. With the 15 x 23 mm (aps-c) sensors, normal
    > is 33mm. Right ?
    >
    > So, are we going to see cheap 33 mm lens, and faster than what we see
    > today ?


    The Sigma 30/1.4 is fairly old news. Big and expensive, though. Unlike FF
    normal lenses, it won't be produced in large quantities.

    David J. Littleboy
    Tokyo, Japan
    David J. Littleboy, Oct 22, 2006
    #6
  7. "Charles" <> wrote:

    > I wondered about the 135 MM lenses for full frame 35 mm film, it used
    > to seem to me they were quite inexpensive relative to other focal
    > lengths.


    You mean like the Canon 135/2.0? (List price in Japan is about US$1100, US
    street price is over US$800.)

    David J. Littleboy
    Tokyo, Japan
    David J. Littleboy, Oct 22, 2006
    #7
  8. Guest

    Paul Rubin Guest

    "David J. Littleboy" <> writes:
    > You mean like the Canon 135/2.0? (List price in Japan is about US$1100, US
    > street price is over US$800.)


    Back in the day, the situation wasn't anything like that. A top
    quality 135/2.8 was around $150. A not-so-top quality 135/1.8 was
    under $200. I got mine for $60 used at a camera store.

    Today the 30/1.4 Sigma cost about as much as a full frame 35/1.4
    Nikkor used to cost. The Nikkor is now about $700 new, but that's
    because all the MF Nikkors are now quite expensive given the rarefied
    demand for them. I got mine used for around $150 on ebay a couple
    years ago.
    Paul Rubin, Oct 22, 2006
    #8
  9. Guest

    george Guest

    <> wrote in message news:ygz_g.167589$1T2.130280@pd7urf2no...
    > I'm back with more silly / newbie questions...
    >
    > In the 24 x 36 mm world, a normal lens is 50mm, normal because it offers
    > the
    > same angle of vision as the human eye. Now, this might be an error, my
    > understanding is that at the equivalent quality, a normal lens is cheaper
    > to
    > make than either a wide angle and/or a telephoto lens. At the same time,
    > it is possible to make normal lenses faster than any other type of lenses.
    >
    > My assumption here is because with the normal lenses you don't have to
    > bend
    > the light at weird angles the way it's done with wide an tele lenses. True
    > /
    > false ?
    >
    > Now here is the real question. With the 15 x 23 mm (aps-c) sensors, normal
    > is 33mm. Right ?
    >
    > So, are we going to see cheap 33 mm lens, and faster than what we see
    > today ?
    >
    >
    > Thanks.
    >
    >


    Not a silly question at all. That is what you should see...however the
    camera companies are taking this opportunity to slip in a major price
    increase by creating APS-C lenses and not doing this. (Just like Danon
    reducing the weight of their yogurt by 25% while keeping the price the
    same...the sneaky price increases are the ones that sell you less for the
    same price and those really irritate me.) Also, if you compare normal
    lenses for view cameras with normal lenses for medium format with normal
    lenses for 35mm, you'll also notice that they get cheaper AND faster with
    smaller coverage area...so, I'd assume that your 33mm lens should be a
    f/1.0-1.2 and cheaper than a 50mm f/1.4 for a 35mm camera...but, I am not
    holding my breath for such a thing.

    George
    george, Oct 22, 2006
    #9
  10. Guest

    Paul Rubin Guest

    "george" <> writes:
    > smaller coverage area...so, I'd assume that your 33mm lens should be a
    > f/1.0-1.2 and cheaper than a 50mm f/1.4 for a 35mm camera...but, I am not
    > holding my breath for such a thing.


    There was a 40/1.4 and 42/1.2 for the Olympus Pen F half-frame 35mm
    system, whose image area was similar in size to APS-C. But I think
    that was easier to do because the whole camera was scaled down
    compared with a 35mm camera, including the mount-to-film distance.
    The 35mm-descended DSLR system cameras are fundamentally
    malproportioned. Canon implemented a workaround for that in some of
    the cheap digital EOS cameras and lenses (EF-S, I think), but I think
    they didn't dare extend it to the higher end models.

    Maybe there will be some fast normal primes for the 4/3 system. For
    35mm-based systems, I think we should consider APS-C sensors to be a
    cost-imposed stopgap, and 24x36mm sensors should become the norm as
    technology improves in the future.
    Paul Rubin, Oct 22, 2006
    #10
  11. Guest

    Scott W Guest

    Charles wrote:
    > I wondered about the 135 MM lenses for full frame 35 mm film, it

    used
    > to seem to me they were quite inexpensive relative to other focal
    > lengths.


    You can make a really cheap 135mm lens, but not if it is also fast. A
    135mm lens at f/1.4 would be very costly.

    Scott
    Scott W, Oct 22, 2006
    #11
  12. wrote:
    : I'm back with more silly / newbie questions...

    : In the 24 x 36 mm world, a normal lens is 50mm, normal because it offers the
    : same angle of vision as the human eye. Now, this might be an error, my
    : understanding is that at the equivalent quality, a normal lens is cheaper to
    : make than either a wide angle and/or a telephoto lens. At the same time,
    : it is possible to make normal lenses faster than any other type of lenses.

    Not necissarily. "Normal" has nothing to do with the cost of the lens or
    even the ease of manufacture. This designation is a somewhat arbitrary
    name for the lens that gives a field of view (along the long edge of the
    image) of about 40 deg. Supposedly this was to match the view of the human
    eye (tho I know my field of view is much wider than 40 deg).

    : My assumption here is because with the normal lenses you don't have to bend
    : the light at weird angles the way it's done with wide an tele lenses. True /
    : false ?

    A lens always has to bend light or it would be a window. :)

    : Now here is the real question. With the 15 x 23 mm (aps-c) sensors, normal
    : is 33mm. Right ?

    Yes. It isn't exact as if I remember my calculations (some time ago) the
    40 deg mark comes at about 32.85 mm. But since Normal is an approximate
    designation you could count anything from about 31 to 35 as a good
    approximation of "Normal".

    : So, are we going to see cheap 33 mm lens, and faster than what we see
    : today ?

    The wider the lens the more difficult it is to grind. And to reduce some
    of the more objectionable edge effects there are more involved optics in
    the lens barrel. But with the prevalence of Digital cameras with similar
    sensor dimensions the mass produced price of wider lenses will get
    cheaper. I can remember back when it was virtually impossible to find a
    lens wider than 18mm without getting a fisheye lens. And the ones down in
    that end of the spectrum were major bucks (>$1000). Now I have found
    several makes of zooms that go down to about 12mm for about $500. So the
    prices are coming down.

    Of course all of this is JMHO and so YMMV. :)

    Randy

    ==========
    Randy Berbaum
    Champaign, IL
    Randy Berbaum, Oct 22, 2006
    #12
  13. Guest

    Paul Rubin Guest

    Randy Berbaum <> writes:
    > I can remember back when it was virtually impossible to find a
    > lens wider than 18mm without getting a fisheye lens. And the ones down in
    > that end of the spectrum were major bucks (>$1000). Now I have found
    > several makes of zooms that go down to about 12mm for about $500.


    Not any that cover 24x36mm! There is a 12mm lens made by Voigtlander
    for the Bessa rangefinders but its rear element comes very close to
    the film (couldn't work on an SLR because no clearance for the reflex
    mirror), and also it's not a zoom.
    Paul Rubin, Oct 22, 2006
    #13
  14. Guest

    Charles Guest

    On Sun, 22 Oct 2006 10:34:34 +0900, "David J. Littleboy"
    <> wrote:

    >
    >"Charles" <> wrote:
    >
    >> I wondered about the 135 MM lenses for full frame 35 mm film, it used
    >> to seem to me they were quite inexpensive relative to other focal
    >> lengths.

    >
    >You mean like the Canon 135/2.0? (List price in Japan is about US$1100, US
    >street price is over US$800.)
    >
    >David J. Littleboy
    >Tokyo, Japan
    >


    I was remembering from back in the late 1970s, back when I thought I
    knew something about the subject. I haven't priced that range of lens
    lately, obviously things have changed.
    Charles, Oct 22, 2006
    #14
  15. Guest

    Guest

    Paul Rubin wrote:

    > Randy Berbaum <> writes:
    > > I can remember back when it was virtually impossible to find a
    > > lens wider than 18mm without getting a fisheye lens. And the ones down in
    > > that end of the spectrum were major bucks (>$1000). Now I have found
    > > several makes of zooms that go down to about 12mm for about $500.

    >
    > Not any that cover 24x36mm! There is a 12mm lens made by Voigtlander
    > for the Bessa rangefinders but its rear element comes very close to
    > the film (couldn't work on an SLR because no clearance for the reflex
    > mirror), and also it's not a zoom.


    I've noticed that the "wide zoom" 18-50mm Sigma kit lens that came with
    my Pentax *ist-DS can actualy cover a full 35mm frame between 50mm and
    about 24mm, wider than that it progressively becomes more vignetted
    until 18mm, when it gives a circular image on the film.
    I tested it on my K1000 just for laughs.
    , Oct 22, 2006
    #15
  16. Paul Rubin <http://> wrote:
    : Randy Berbaum <> writes:
    : > I can remember back when it was virtually impossible to find a
    : > lens wider than 18mm without getting a fisheye lens. And the ones down in
    : > that end of the spectrum were major bucks (>$1000). Now I have found
    : > several makes of zooms that go down to about 12mm for about $500.

    : Not any that cover 24x36mm! There is a 12mm lens made by Voigtlander
    : for the Bessa rangefinders but its rear element comes very close to
    : the film (couldn't work on an SLR because no clearance for the reflex
    : mirror), and also it's not a zoom.

    Since we were talking about the smaller APS sensor I was confining my
    comment to that. And as to SLRs I have seen several makes of zoom lens for
    my Ist-DS that are (at last check) in that price and zoom range. True
    fewer lenses are being made for a full frame (35mm film) sensor, but until
    more full frame bodys are marketed this is probably going to continue. In
    part the price will fall for those items that there is a larger desire
    for. Even if the materials cost is equivalent. A brake assembly for a
    steam driven car will cost more than one for a new GM. Even tho the
    materials cost would be about the same. :)

    On the other hand, when full frame sensors become the norm on the majority
    of digital camera bodies I would expect the cost of FF lenses to fall to
    some extent. Of course the rising costs of materials, manufacturing and
    shipping will offset that to an extent. Also few FF cameras will use a
    simple 1970's lens, and all those additional built in devices will add to
    the price (few early '70s SLR lenses included a chip for reporting the
    f-stop, had an internal motor for AF, or included IS technology). But I
    would expect that whatever size and style of sensor is most prevalent at
    the time will be at least comparitively less expensive than those not in
    current wide spread use (speaking of most recent vintage here).

    JMHO

    Randy

    ==========
    Randy Berbaum
    Champaign, IL
    Randy Berbaum, Oct 22, 2006
    #16
  17. Guest

    Paul Rubin Guest

    Randy Berbaum <> writes:
    > : > I can remember back when it was virtually impossible to find a
    > : > lens wider than 18mm without getting a fisheye lens. And the
    > : > ones down in that end of the spectrum were major bucks
    > : > (>$1000). ...Now I have found several makes of zooms that go
    > : > down to about 12mm for about $500.
    > : Not any that cover 24x36mm!
    >
    > Since we were talking about the smaller APS sensor I was confining
    > my comment to that.


    Huh? Those $1000+ 18mm lenses were for 24x36mm. If you're talking
    about smaller formats, then of course there were shorter lenses. 6mm
    was a fairly standard wideangle for 16mm cinema, I think. The Minox
    still camera had a very good 15mm prime. And there were Beaulieu 8mm
    movie cameras that had a 6-70/1.4 zoom in the 1970's or so:

    http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280037999767
    Paul Rubin, Oct 22, 2006
    #17
  18. Guest

    Pete D Guest

    "Paul Rubin" <http://> wrote in message
    news:...
    > <> writes:
    >> Now here is the real question. With the 15 x 23 mm (aps-c) sensors,
    >> normal
    >> is 33mm. Right ?
    >>
    >> So, are we going to see cheap 33 mm lens, and faster than what we see
    >> today ?

    >
    > I think it's difficult because the lens mount to film plane distance
    > is still the same as with a full frame SLR. So the 33mm lens has to
    > be built something like a full frame SLR wideangle and not like a
    > normal lens. I'd also say the absence of a 33mm-ish macro lens is
    > even more annoying than the situation with normal lenses. There are
    > good 35/2 and 35/1.4 lenses available if you want to pay for them.
    > But there's no good flat-field macro lens in that focal length.
    >
    > IMO, these APS-C DSLR's using 35mm SLR lenses are something of a
    > stopgap because full frame sensors are still quite expensive. But I
    > think that will improve over the next year or two. After rebates an
    > EOS-5D is just a little over $2K, which is not much over what the
    > Nikon D100 (maybe the first more-or-less consumer DSLR) cost when it
    > came out.
    >
    > Remember that Nikon's early DSLR's, the E2 and E3, cost over $10K each
    > and used 2/3", 1.3 megapixel sensors or thereabouts. I hope Nikon
    > will release some full frame models at PMA 2007, initially including a
    > D300 at today's D200 price level. Once there is competition for the
    > 5D, these cameras should soon reach the D80 price level. Then you'll
    > be able to use your 50mm normal and macro lenses.


    Nice dream but unless they improve the yield for the lager sensors you will
    be waiting a bit longer.
    Pete D, Oct 22, 2006
    #18
  19. Guest

    Paul Rubin Guest

    "Pete D" <> writes:
    > Nice dream but unless they improve the yield for the lager sensors you will
    > be waiting a bit longer.


    They have already improved the yield tremendously for sensors of all
    sizes. 36x48mm sensors (found in medium format backs) were unobtanium
    a year or so ago. The D1 was $5000 when it came out. Its predecessor
    the E3 was over $10000 and had a much smaller sensor than the D1. The
    EOS-1DS was around $8000 and now the 5D is just over $2000. There's
    no reason to expect this process not to continue.
    Paul Rubin, Oct 22, 2006
    #19
  20. "Charles" <> wrote:
    > "David J. Littleboy" <> wrote:
    >>"Charles" <> wrote:
    >>
    >>> I wondered about the 135 MM lenses for full frame 35 mm film, it used
    >>> to seem to me they were quite inexpensive relative to other focal
    >>> lengths.

    >>
    >>You mean like the Canon 135/2.0? (List price in Japan is about US$1100, US
    >>street price is over US$800.)
    >>

    >
    > I was remembering from back in the late 1970s, back when I thought I
    > knew something about the subject. I haven't priced that range of lens
    > lately, obviously things have changed.


    Sorry about the cheap shot. The 135/2.0 is a great lens, but it costs like a
    great lens.

    Seriously, though, you are quite right: there are a _lot_ of fun and
    affordable fixed-focus lenses for FF 35mm, both new and used. I have a
    friend who owns 17 or so 50mm lenses for his Leica and insists they all have
    different "characters".

    David J. Littleboy
    Tokyo, Japan
    David J. Littleboy, Oct 22, 2006
    #20
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