Dust in New Sigma 30mm 2.8 Art. Common occurrence?

Discussion in 'Native Lenses' started by Thinh Ly, Sep 30, 2013.

  1. Thinh Ly

    Thinh Ly Mu-43 Regular

    Sep 26, 2012
    Washington D.C.
    Hey m43ers,

    I just got my Sigma 30mm today but sadly there's some dust under the front element. I did a quick google and found this thread about it on DPR (http://www.dpreview.com/forums/thread/3352687#forum-post-50511604). Does everyone else here have dust issues with their Sigmas too or should I get an exchange?

  2. speedandstyle

    speedandstyle Mu-43 Hall of Famer

    Odd! First I had heard of this. I am sure this happens from time to time.

    I have the older 30mm and it is fine. Perhaps there was a dust storm one day at the factory?
  3. Thinh Ly

    Thinh Ly Mu-43 Regular

    Sep 26, 2012
    Washington D.C.
    I sent it in for an exchange. From f/16 - f/22 the dust was visible and it was about 5-7 dots. That is WAY too many. Makes me wonder about the QC at the factory.
  4. nanolab

    nanolab New to Mu-43

    Sep 13, 2012
    It's a dust on sensor, not on lens.
  5. tjdean01

    tjdean01 Mu-43 Top Veteran

    Feb 20, 2013
    Yup. If it's on the lens you wouldn't see it. It would just add an overall blur to a large portion of the photo that probably wouldn't be visible.
  6. gochugogi

    gochugogi Mu-43 Veteran

    I own 26 lenses. Most of them shipped with dust preinstalled at the factory. However this dust is normally not apparent at a quick glance. If I peer through the rear and shine a LED down the front, even brand new Canon L series optics show dust! Sometimes spots of oil too. I've owned 7 Sigma lenses and they had more dust than my Nikkor and Canon lenses. One even had a hair and factory fingerprint! I just bought a Sigma 60 2.8 (M43 mount) and did the LED test and, yep, dust inside. I'd be worried if there wasn't any! Sigma might have to raise prices if they installed an optic cleanroom! At $189 and still made in Japan I can appreciate a few spots of dust. Unless extreme, they make no difference optically. My Sigmas are my dirtiest lenses and they get a little worse with time and use: they vent air as elements move and draw in more dust. If you're anal retentive it will bug you to no end but learn to live with it or don't peer down your lenses.