Circular Polarizer on Panasonic 20mm f1.7

Discussion in 'Native Lenses' started by timallenphoto, Jul 27, 2011.

  1. timallenphoto

    timallenphoto Mu-43 Veteran

    266
    May 20, 2011
    Kent, England
    Is this possible and if so is there one that someone can recommend?
     
  2. Howi

    Howi Mu-43 Veteran

    208
    Feb 23, 2011
    Sheffield
    Howard
    Yes! filter just screw on,
    Panasonic one is quite expensive
    other options are B & H and Hoya (Pro), Marumi, Sigma
    word of warning - don't go for the cheap end, you will only be wasting your money.
     
  3. Danny_Two

    Danny_Two Mu-43 Regular

    182
    Oct 30, 2010
    London
    Just look on amazon for a 46mm filter and there will be a lot of options. Ive got a cheap(ish) Hama one, although I find it fairly pointless.
     
  4. leonberdi

    leonberdi Mu-43 Regular

    133
    Apr 15, 2011
    Montreal
    Could I use a step-up ring to use a 52mm circular polarizer?

    My wife has a nice 52mm circular polarizer left over from her SLR-film days. I was hoping to use it on the Panny 20 with a step up ring. I thought this might even be advantageous - when turning the polarizer I would be adding less of that stress that people warn about on the auto-focus motor. Is that correct?

    Is using a step-up ring a good idea for a circular polarizer on a panny 20?
     
  5. The weight of a filter would only have an impact on the focus motor of an externally focusing lens where the front element moves in and out and/or rotates. I think the 20/1.7 is an IF lens so a step-up ring and a slightly larger filter will not affect the autofocus.

    If you have a collection of lenses with many different filter thread diameters it will make financial sense to choose perhaps two or three common filter sizes and use step-up rings.
     
  6. Howi

    Howi Mu-43 Veteran

    208
    Feb 23, 2011
    Sheffield
    Howard
    No!No!No! - wrong on all accounts.
    The Pany 20mm front element and surrounding area , moves backwards and forwards as the lens focusses. It also retracts slightly when switching off.
    Putting on a step up ring could stop it retracting properly.
    Can't see where you are coming from, regarding less stress????
    Just get a proper 46mm CPL, it's cheaper than new lens.
    There is a review of the 20mm somewhere on the net, that covers the above point.
     
  7. veereshai

    veereshai Mu-43 Top Veteran

    777
    May 12, 2011
    Arlington, VA
    Recently, I got step-up rings (46->52mm and 52->67mm) for the 20mm f1.7. I have a 52mm CPL and 67mm ND 2 stop filter that I use with my canon system, and with the help of step up rings, I can use them with the 20mm as well. Infact I stacked them together and got a few shots, they're posted here:
    https://www.mu-43.com/f80/panasonic-20mm-f-1-7-image-thread-298/index97.html#post131911

    The first two were shot with a G1+20mm+52mm CPL+67mm ND filter. As you can see, the CPL did cause some problem in the first photograph (vignette only on one side), I guess I'll just have to be more careful when I make photographs with this combo.


    EDIT: Howi, not sure why it would be a problem. Yes, I was careful not to switch it off, but the rotating front element shouldn't be that big a problem. I always focus first and then turn the CPL. Your point does get me thinking about how it can damage the lens.
     
  8. sylvesterii

    sylvesterii Mu-43 Regular

    26
    Jun 21, 2011
    I don't think the 20mm front element rotates. Just moves in and out slightly.

    One bonus would be the 14mm f/2.5 has the same filter size, Not sure about vignetting issues, but theoretically the same 46mm polarizer can work on both.
     
  9. veereshai

    veereshai Mu-43 Top Veteran

    777
    May 12, 2011
    Arlington, VA
    The vignetting was my mistake and some of my friends said it was because of differential polarization, not sure what that meant though :).
     
  10. Howi

    Howi Mu-43 Veteran

    208
    Feb 23, 2011
    Sheffield
    Howard
    The front element does not rotate, but it does move in and out. It does not move much, but if the stepping ring prevents it from fully retracting, it may cause damage over time.
    46mm filter fits both 14 and 20 mm but be careful with the 14 as it is getting to be on the wide side for a CPL - leads to uneven blue sky's.
     
  11. dcisive

    dcisive Mu-43 Veteran

    460
    Feb 19, 2010
    Salt Lake City, Utah
    Lee
    I just ordered the 14 and 20 along with a 46-52mm step ring and a B+W THIN circular polarizer. It should work fine, and I'll be sure to try it to make sure. I've had the 20mm f1.7 before and used a step ring on it with no issues. Just don't overtighten the ring and it should clear the focus action of the lens element just fine.
     
  12. leonberdi

    leonberdi Mu-43 Regular

    133
    Apr 15, 2011
    Montreal
    Has anyone else used a step-up ring on a Panny 20mm? I'm scared of damaging the camera, so I'd like to get more opinions before I order one.

    A related question: if the front element of the Panny 20mm moves back and forward, what then is the point of it having threads to attach filters if the lens itself could be damaged? Wouldn't this be a design flaw?
     
  13. FastCorner

    FastCorner Mu-43 Veteran

    310
    May 28, 2011
    I've used a 46-52 step-up ring and it did jam the lens when powering off. If you don't intend to take the ring off, you can use a few windings of thread to keep the ring from being flush with the end of the lens and this should be enough to keep the lens safe. That said, you're better off getting 46mm filters.
     
  14. addieleman

    addieleman Mu-43 All-Pro

    Aug 5, 2010
    The Netherlands
    Ad
    If you really want to use a step-up ring, start by putting a 46mm filter ring (e.g. by removing the glass of an old 46mm filter) on the lens and then add the step-up ring. That way the lens can retract freely.

    It is indeed true that the 20's focus motor has to move everything that's on the lens' filter thread back and forth. A normal 46mm polarizer and aluminium lens hood shouldn't be a problem, I imagine that Panasonic thought of this while designing the lens; however, I hesitate to use my Nikon 52mm polarizer with its original, fairly heavy lens hood combo.
    I agree. Take the safe and easy route and simply buy a good 46mm polarizer from B+W, Hoya or Panasonic. You can also look out on eBay for a used 46mm linear polarizer, on an MFT camera there's no need for a circular polarizer (CPL). I used a Nikon linear polarizer on my 14-45mm and 45-200mm lenses with very good results.
     
  15. leonberdi

    leonberdi Mu-43 Regular

    133
    Apr 15, 2011
    Montreal
    Thanks for the info guys. I think I'll be searching for a linear polarizer now