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12-35mm F2.8 Panasonic lens topic
  • 492 Replies sorted by
  • HillTop1HillTop1

    @Mikhailk wow, thanks for pointing this out. I was gonna place an order for this lens this Thursday. This is a bummer, panasonic didn't think people will notice?

    So could this be something that could be fixed via a firmware or some design flaw?

  • gamebgameb

    Sounds like a real defect. Hmmm. But as long as it happens only during zooming... I am not a fan of zooming anyway. Its not really very filmic.

  • nomadnomad

    If it's not parfocal, you can't film when zooming anyway…

  • chazzmoechazzmoe

    Does anyone know if when mounted on a Af100 and you adjust the iris if it's "hard" click like steps or is it smooth like a built in lens? I had the 14-35mm f2 which optically was great but if you were outside and the sun was moving in and out and you had to adjust the iris it pretty much killed the take.

  • stoneystoney

    As zoomin in, the aperture opening should get wider to keep the constant f-number. The f-number is a ratio :)

    I wonder if it's simply a firmware bug that doesn't sync the zooming and aperture opening. But I wouldn't believe it before seeing a test clip though.

  • MikhailKMikhailK

    @nomad, this lens is parfocal.

    @stonebat, Yesterday I looked at the front mount of my lens and noticed the following. I set f/2.8 and started zooming in. The more I zoom in, the more the aperture squeezes. Maybe I'm wrong but I have a conclusion that @Vitaliy_Kiselev was right:

    "As issue can be just with lens firmware error. It tries to keep F number during zooming, but fail to do it properly. ------- So, it can be non-constant F number zoom with electronic adjustment. ------- "

    Also you should keep in mind that during zooming with this lens while taking photos, you clearly hear the lens' motor and see this flicker effect. When you zoom in the cinema mode (without pressing the REC button) you also here this sound and see the same flicker effect. When you press the REC button this sound almost disappears, but this flicker effect is still there (it's getting less noticable but it's there).

  • sam_rides_a_mtbsam_rides_a_mtb

    @Mikhailk How do you know this lens is parfocal? From doing your own tests or did you read this somewhere?

  • MikhailKMikhailK

    @sam_rides_a_mtb it's very easy to find it out.

    You gotta zoom in and after that focus on some object. Then zoom out (and remember to stand on the same place). Then (standing on the same place) zoom in onto the same object. If this object is still in focus then your lens is parfocal.

  • nomadnomad

    Sorry, it's not about zooming in and out.

    Just focus at tele very carefully (wide open, of course) and zoom to widest, check if it holds focus.

  • MikhailKMikhailK

    @nomad I didn't get it - if your comment relates to me or not. Anyway, even with your method I can say it's parfocal.

  • nomadnomad

    Maybe sample variation? I was just commenting on divergent commentaries here, I didn't test it myself (yet).

  • MikhailKMikhailK

    @Vitaliy_Kiselev, would you be so kind to comment your thoughts on the thing I sad:

    "Yesterday I looked at the front mount of my lens and noticed the following. I set f/2.8 and started zooming in. The more I zoom in, the more the aperture squeezes".

    Does it really mean it's a fake constant f/2.8 lens?

  • Vitaliy_KiselevVitaliy_Kiselev

    Does it really mean it's a fake constant f/2.8 lens?

    You can cover the contacts and check :-)

  • MikhailKMikhailK

    @Vitaliy_Kiselev sorry, I don't get your point. What do you mean? Anyway, is my opinion correct that this is a "fake" constant f/2.8 lens?

  • Vitaliy_KiselevVitaliy_Kiselev

    sorry, I don't get your point. What do you mean?

    I mean - cover the lens contacts and film zooming in.

  • MikhailKMikhailK

    @Vitaliy_Kiselev, thanks for the advice. I'll do it.

  • LPowellLPowell

    I've observed aperture glitches in most of the Panasonic and Olympus zoom lenses I've tested. My conclusion is that none of these lenses are built with a mechanically constant aperture - they all use electronic iris control to simulate the aperture you select. This includes the following lenses:

    Olympus 35-100mm f2.0

    Olympus 14-54mm f2.8-3.5

    Olympus 9-18mm f4-5.6

    Panasonic 14-50mm f2.8-3.5

    Panasonic 14-45mm f3.5-5.6

    Panasonic 45mm-200mm f4-5.6

    Panasonic 14-140mm f4-5.8

    Panasonic 45-175mm f4-5.6

    What happens when you zoom is the camera detects the altered focal length and electronically adjusts the iris to dynamically maintain the aperture you've selected. But in practice, the iris is not stepless and occasionally clicks when adjusted. What's worse is that since the camera is unable to track continuous zooming in real time, dynamic iris adjustments often lag behind the zoom.

  • Vitaliy_KiselevVitaliy_Kiselev

    What's worse is that since the camera is unable to track continuous zooming in real time, dynamic iris adjustments often lag behind the zoom.

    I think this guys need to work on firmware.
    It is not rocket science, especially comparing to their AF performance.

  • nomadnomad

    In the old days aperture compensation was done by hardware (mechanics).

    My wonderful Rokkor 35-70mm does it smooth, silent and without a glitch…

  • Vitaliy_KiselevVitaliy_Kiselev

    About our lens :-) :

    http://www.quesabesde.com/noticias/panasonic-lumix-g-x-12-35-mm-f2.8-analisis-fotos-muestras,1_8917

  • MikhailKMikhailK

    This article doesn't say anything about the glitch we discussed.

    I do realize that this lens is "probably" one of the best wide-angle zoom for photographers. But for videographers it's not for sure...

  • gamebgameb

    In bkmcwd post on page 2 (his friends video), there are a few zooms in there, they look fine to me, a part from, as I said I don't like zooming too much. I can understand what the issue is you are telling us, MikhailK, but may be its not so dramatic as to say, its not a good lens for videographer...

  • nomadnomad

    Seconded. If, as a filmmaker, you regard a zoom more like having different focal lengths in one handy case (instead of really zooming too much while filming), it should still be a great lens. The image characteristics look much better than most of the supersharp primes for MFT.

  • MikhailKMikhailK

    @nomad, @gameb, In general I agree with you that this lens is one of the best supersharp primes for MFT. And I don't zoom everytime I shoot something. And I agree that having different focal lengths in one handy case is a must. But sometimes there are situations when (suddenly) you realize you gotta make this shot with zooming in or out. It all depends on the artistic way you wanna have your picture made. Any way, I saw no motion picture made with primes only! Also, when I shoot my child (she's 2,5 years old) who can't "hold still" at all, zooming in/out helps me a lot in some cases.

  • gamebgameb

    @MikhailK: "I saw no motion picture made with primes only!" Sorry, MikhailK, but I think it is the other way round: zooming was and is very rarely used in cinematograhic films, a part from the italians (especially in the 60s and 70s), a lot of asian productions or other rather cheap productions: Primes is what you normally use in cinema.

    I am really looking forward to work with this lens. Like everything, it depends on the way you use things. But I still don't have it really clear, is this lens parfocal or not? It is important to know even if you don't zoom. If it is parfocal, why does Panasonic not mention it?

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