Too bad the 12-50mm has only 5 blades...

Discussion in 'Native Lenses' started by TetonTom, Jun 16, 2013.

  1. TetonTom

    TetonTom Mu-43 Regular

    I'm pretty happy with the 12-50mm on my EM-5, compared to other kit lens experiences I've had.
    But... Then you get something like this every once in a while. I did a quick read on the specs and found out that this lens has only got 5 aperture blades. I never really heard of that before...
    "Macro" setting, Aperture priority, f/14, 1/250 sec.
  2. speedandstyle

    speedandstyle Mu-43 Hall of Famer

    I am with you dude! I don't know why they insist on anything less than 6 blades. It could be worse though as there are some 2 - 3 and 4 bladed iris lenses out there.
  3. fsuscotphoto

    fsuscotphoto Mu-43 Top Veteran

    Feb 15, 2013
    St. Cloud, FL
    I bet that would have added a bit more to the price.

    Sent from my iPad using Mu-43 mobile app
  4. TetonTom

    TetonTom Mu-43 Regular

    I guess I just need to remember that what I really bought was "convenience", and to go beyond that I should mount up some other glass.
  5. sinclair

    sinclair Mu-43 Veteran

    Unless you have something against 5 sided things, I don't see it as a bad thing. It doesn't distract from the image in my eyes.
  6. Just Jim

    Just Jim Mu-43 Top Veteran

    Oct 20, 2011
    it's kind of distracting, not because of the quality of the bokeh as it's pretty smooth, but that it's a geometric shape in a very natural space. Although that's a sharp shot, and those things can be shopped up nicely by removing them, or changing the shape just a touch, so it's not so... geometric? Or crop it real tight where the petal edges soften up.
  7. Mercurio

    Mercurio Mu-43 Veteran

    Jul 17, 2012
    Bogotá, Colombia
    Are the pentagon artifacts at the left of the image generated by the 5 aperture blades? I the case of a 6 blades lens, it would be an hexagon?
  8. Vivalo

    Vivalo Olympus loser Subscribing Member

    Nov 16, 2010
  9. sinclair

    sinclair Mu-43 Veteran

    But if you study nature, you learn it's full of geometric shapes. I see them in almost everything. It's the basis of the golden ratio, which is the geometry in/of nature. But then I've been told I see the world different from "normal" people. ;)
  10. speedandstyle

    speedandstyle Mu-43 Hall of Famer

    Maybe $20! The Olympus kit lenses have 7 bladed irises as do the Panasonic kit lenses. In fact the only other m4/3 lens I could find with anything less was the Olympus 17mm f2.8{it also has a 5 bladed iris}.
  11. speedandstyle

    speedandstyle Mu-43 Hall of Famer

    Yes, a 5 bladed iris creates the pentagram highlights. And you are right, a 6 bladed iris would create a hexagon shape. However a hexagon is much closer to a circle than a pentagram is. It is also possible to make the blades with a slight curve and this smooths it out even further. Keep in mind that it isn't just the highlights that are affected but all light that goes through. This is why the best lenses have many more blades, as many as 20{perhaps even more although I have never heard of any with more}.

    From wikipedia on the subject of "diaphragm{optics}"
  12. Ross the fiddler

    Ross the fiddler Mu-43 Hall of Famer

    I actually like the look of that. It looks 'cool'. :cool: :biggrin:
  13. Just Jim

    Just Jim Mu-43 Top Veteran

    Oct 20, 2011
    Not in equilateral shapes... If I see a photo with an equilateral shape I see a man made element. Might be me.
  14. twokatmew

    twokatmew Mu-43 All-Pro Subscribing Member

    Jun 1, 2012
    Lansing, MI, US
    Interesting. The Oly 17/2.8 must have rounded blades, because I got nice round bokeh balls from that lens. One example:

    Untitled by twokatmew, on Flickr
  15. ^^ That image (very nice, BTW) is shot at f/2.8 when the aperture blades have fully retracted and the lens opening is circular. The shape and number of blades will only be obvious in out-of-focus highlights when the lens is stopped down.
  16. twokatmew

    twokatmew Mu-43 All-Pro Subscribing Member

    Jun 1, 2012
    Lansing, MI, US
    Thanks x 2! Just learned something. :smile:
  17. TetonTom

    TetonTom Mu-43 Regular

    Great shot w/the 17mm!

    This thread also got me thinking that I still haven't gotten sun-stars with the 12-25 that I'm happy with. I was in love with my Nikon 12-24; it spent more time mounted than any other lens. I seem to remember the sun-stars most always being pleasant, more so than I can get with this Olympus lens.

    I know this is NOT any kind of objective comparison, but look at these shots taken almost exactly a year apart in very nearly the same place. The first one is the OM-D w/12-25 (at 12mm), the second is Nikon D7000 w/12-24 (at 16mm).
    I would take the 7 blades of the Nikon over Olympus' 5 any day...


  18. I can't say that I am totally enamoured with how the 12-50mm does sunstars at small apertures either, but this comparison sure does show how much better the m4/3 cameras are at keeping their sensors clean :smile: (Had the same trouble with my old Canons as well).
  19. darosk

    darosk Mu-43 Top Veteran

    Apr 17, 2013
    Kota Kinabalu, Malaysia
    There are equilaterals in nature if you think about it - Giant's Causeway and other similar rock formations, honeycomb (insect-made - but nature all the same), certain kinds of ferns grow their leaves in hexagonal shapes (although the shape is not always apparent due to gravity and other factors). Snowflakes as well, and plenty other small or microscopic things, no doubt.
  20. speedandstyle

    speedandstyle Mu-43 Hall of Famer

    At what aperture was the picture taken? All lenses will give round bokeh balls if fully opened{the blades are not in the way}.
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