Pentax SMC-M 50mm 1.4 vs SMC-A 50mm 1.4?

Discussion in 'Pentax' started by arraga, Aug 19, 2005.

  1. arraga

    arraga Guest

    I've heard conflicting reports about them; some people say that the
    optics are the same, and others that the SMC-A is better.

    What about the SMC-M 50mm 1.7 vs the SMC-A 50mm1.7 vs the 1.4's? I'm
    basically looking at resolution, contrast, and shootability at low
    apertures and wide open; I prefer an uniformly ok/good lens at low
    apertures, than one, while being a wunderkid at f/8, is fuzzy down the

    Regardless of the 'A' setting, which is something good to have, but not
    essential to me, can someone enlighten me?

    arraga, Aug 19, 2005
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  2. arraga

    Paul Mitchum Guest

    You might try here:
    < mm Lenses>
    Scroll down to the 'M vs. A' section.

    (From this site: <>.)

    Essentially (judging from the comments there): The A wins, but only by a
    tad. The real difference comes when you compare 50/1.7 versus 50/1.4 and
    50/1.2. I've been looking for a cheap SMC-A 50mm just so I can get the A
    setting, too. :)
    Paul Mitchum, Aug 19, 2005
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  3. arraga

    Mark Roberts Guest

    Man, you're opening up a can of works here!
    I'll just say that I like the 1.4 *better* than the 1.7 - not
    necessarily meaning that it's sharper, just that the overall combination
    of sharpness, bokeh, etc appeals to me more.
    For further reading:
    or Prime Lenses
    Mark Roberts, Aug 19, 2005
  4. I have a mint appearance SMC-M version of the f1.4. At normal apertures
    such as f4 to f8/11 I was impressed by the results. Then I came across a
    photo journal where they said that out of all the commonly available
    standard lenses they tested (about 6 at least), only the Pentax f1.4 fell
    below their MTF machine's readout limits at full aperture. The result was
    simply missing. So I did a <quick> test with mine at f1.4, and f5.6. The
    mag appeared to be correct, at f1.4 mine was really horrid; but OK, as
    before, at f5.6. Could I have mis-focused? Yes; I did take care, but didn't
    have any charts in front /behind the standard one as a check.
    I also have an f1.7 but haven't done any tests.
    Malcolm Stewart, Aug 19, 2005
  5. arraga

    arraga Guest

    arraga, Aug 19, 2005
  6. arraga

    Cheesehead Guest

    The M series, in general, has been Pentax' generally less-than-stellar
    line of lenses.
    There were a few outstanding items in the line, but generally average
    Not bad, but not outstanding.

    Many of the "A" lenses were M designs with
    (a) the "A" contact for added camera control, and
    (b) improved coatings for improved contrast.
    The "A" coatings are a purple cast and thus a bit cooler than the brown
    cast of the M series. For Fuji C-41 film I like "A"; for Kodak, M.
    Both are excellent for b&w.

    The F & FA (autofocus lens series) have a combination purple/brown
    coating cast as well as improved optical design. The F50/1.7 and
    FA50/1.4 are the most popular right now. And for good reason --
    they're very, very nice lenses.

    With any camera brand and lens series the results you get depend on the
    film as well as the lens characteristics. Try them and see.

    Even in LF, Fujinon lenses have a green cast and are highly respected
    for b&w, but the cast adds a color shift when shooting chromes.
    Schneider is the best all-around. But again if one shoots only or
    primarily b&w (as do many LF shooters), the choice of available lenses
    widens. Treat 35 the same way. Test with your preferred film. If you
    see a diff, go with your best results.

    Personally, I have a wide selection of lenses. Two brands: Six Pentax
    and two Tokina.
    Each does its own job well for my type of shooting.

    Take your time. Build your lens selection from experience. Buy a
    Shoot with it. If you like the results, keep it. If not, resell it.
    You'll likely not lose. There's no reason to keep a lens that doesn't
    do what you want. And in the long run you'll win by getting
    what works best for you.

    Cheesehead, Aug 19, 2005
  7. arraga

    Jeremy Guest

    Pentax allegedly tweaked the optical formula a bit when they came out
    with the "A" lenses, and there is allegedly a better sharpness on the A's.

    I have both the SMC A 50mm f/1.7 and several SMC Takumar screwmount
    lenses in f/1.4 (50mm) and f/1.8 and f/2 (55mm). I can't see any
    discernable difference, except that the 55mm f/1.8 seems a tad sharper
    than the 50mm f/1.4 SMC Takumar.

    My brother uses a Pentax M 50mm f.1.7 and his shots are as sharp as I've
    ever seen.

    They're all good--the differences are so subtle that they are more
    apparent in testing, rather than real life situations. I much prefer
    the more solid screwmount versions. The A lenses have that cheesy 70's
    look about them, and they do not have the silky-smooth feelwhen turning
    the focus ring. The aperture ring is also not as smooth and
    solid-feeling as are the older SMC Takumars. I don't think that any of
    this has any effect on the image quality, but there is a tactile sense
    of gratification when using the classic Pentax bodies and lenses. All
    that metal feels good . . .
    Jeremy, Aug 19, 2005
  8. arraga

    Tony Polson Guest

    The 50mm f/1.4 A version is significantly sharper than the M version
    and has improved SMC coating. Both have very smooth bokeh. The M
    version is best avoided because it is unsharp at all apertures.

    There is very little difference between the 50mm f/1.4 A and M
    versions. The A version has the improved SMC coating.

    A versions are useful if you use later Pentax AF film bodies and any
    of the *ist D/DS/DL bodies, because with an A lens you get all
    functions except AF.
    Tony Polson, Aug 19, 2005
  9. arraga

    Tony Polson Guest

    Sorry, the second paragraph refers to the f/1.7, not the f/1.4. The M
    and A versions of the f/1.7 differ only in the SMC coating, so the
    difference is very small.

    Apologies for the confusion.

    Tony Polson, Aug 20, 2005
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