Panasonic 12-35mm dust in rear part of lens, repeated problem

Discussion in 'Native Lenses' started by AndrewS, Jun 2, 2014.

  1. AndrewS

    AndrewS Mu-43 Regular

    May 12, 2012
    This posted as advice to forum members and to any Panasonic representatives who may be watching this forum. I would also appreciate hearing from members who have had the same problem. I have now bought and used four copies of the Panasonic 12-35mm f2.8 lens. Each of them has had the same problem. The lens is clear of foreign matter on purchase. After sometime in use, varying from one week to a month, in a clean, non dusty environment, foreign matter appears either on the inside of the rear element, or in the next innermost element. In each case this has consisted of a little (about 1mm) curl of some matter like a worm, together with one or several spots nearby. I sold the first two copies and sent the third to the Australian repair service which is Definitech. after two tries they managed to remove the foreign material from the third lens. I bought a fourth copy of the 12-35mm in a kit with the GH4 and after a week it too has the same kind of foreign matter on the inner rear element as I had seen previously. I have owned and used 14 other M43 lenses over the last 5 years, none of them having this problem. Therefor I conclude the problem is specific to the 12-35mm and is due to some fault most likely in the mechanical design of the inner components of the lens. Myhypothesis is that the zoom action is causing abrasion of some components leading to extrusion and deposition of shaved particles. Has anyone else seen this problem ? Could 12-35mm owners please shine a LED torch into the rear element of their lens and report back ?
    I am well aware that a few bits of foreign matter in a lens does not affect performance appreciably but they do depress resale value and in any event a maker's premium lens should not have a problem like this.
  2. LowTEC

    LowTEC Mu-43 Regular

    I don't need to use a LED torch to see there are plenty of lints and dust at the back element of my 12-35, after the few weeks of usage since brand new. I can ensure you I picked the absolute cleanest lens from over 3 different stores. So much for dust and water resistance design. I tried to sell it but buyers have plenty to choose from the used market, so I never able to sell mine 60% off the original priced that I paid for, therefore I could never switch to the 12-40 :(
  3. arch stanton

    arch stanton Mu-43 Veteran

    Feb 25, 2012
    Real Name:
    Interesting thread - I'm thinking about buying one of these...I wonder how many other people have experienced this?
    • Like Like x 1
  4. poopstick

    poopstick Mu-43 Regular

    Aug 9, 2013
    Burlington Ontario
    Same here! There's a bunch of dust in the back of my 12-35. How ironic, that it is the only weather sealed lens I have, and the only one with this problem.
  5. budeny

    budeny Mu-43 All-Pro

    Mar 4, 2014
    Boulder, CO
    no dust in my 12-35 after one year
  6. owczi

    owczi nareteV 34-uM

    Need to check my 35-100, but it's internal zoom - I think that the way the dust is getting into the 12-35 is probably via the extending front element while zooming in and out. I don't suppose the weather sealing is some accordion / bellows type gasket but rather the lens barrel is moving inside a seal?

    Simply put - they don't make 'em like they used to :) Most of my Canon FD lenses are *edit: almost* dust free, that includes zooms and macro with a lot of barrel movement.
  7. laser8

    laser8 Mu-43 Veteran

    Jan 29, 2013
    Mare nostrum, Istria
    Got some dust in mine too, but I have some in all lenses. I read an article on lensrentals about this topic some time ago and basically you need a shattered front element to see some IQ deterioration. I'd not worry too much.
    • Like Like x 2
  8. barry13

    barry13 Super Moderator

    Mar 7, 2014
    Southern California
    Real Name:
    A dirty or damaged rear element is much worse for the image than the front element.
    Think about it; the RE is normally much smaller so any dirt will be magnified (compared to the FE).

  9. Dave Reynell

    Dave Reynell Guest

    Thank goodness I saw this post. I was considering buying a 12-35. As for your comment on modern-day lenses (build quality) I agree wholeheartedly. I still have four beautifully built Pentax legacy lenses - one a gift, the other three purchased by me thirty years ago - to this day not a speck of dust or anything between the elements. Solid metal barrels too !

    As a result of the "digital explosion", as convenient as it has been, we have witnessed a lowering in the quality of camera bodies and lenses. The competition is fierce and has the makings of a rat-race.