46mm filters?

Discussion in 'Accessories' started by ssgreenley, Jul 10, 2011.

  1. ssgreenley

    ssgreenley Mu-43 Top Veteran

    509
    May 12, 2011
    Hi all! I'm looking at a couple of filters now that I've finally gotten my hands on a 20mm. Two questions, 1) does anyone make a multi-coated, linear polarizer? 2) how about graduated neutral density filters? Thanks!
     
  2. ssgreenley

    ssgreenley Mu-43 Top Veteran

    509
    May 12, 2011
    *tap, tap* Is this thing on?

    I'm guessing that they don't make either of these filters then. Graduated neutral density can be easily replaced by lightoom, so I understand that, but what about a good polarizer? Is it better to go uncoated linear, or should I pay extra for a circular just for the flare reducing coats?
     
  3. thearne3

    thearne3 Mu-43 Top Veteran

    807
    Jan 28, 2010
    Redding, CT USA
    I'm no expert, but what would the point of multi-coating be on a linear polarizing filter? By definition, the unwanted stray light would be filtered out by adjusting the direction ring of the filter.

    OTOH, a circular polarizer would need such coatings, since it has no such adjustment option.

    Perhaps there are some experts who can 'shed more light' on this... :rolleyes:
     
  4. Hikari

    Hikari Mu-43 All-Pro

    Nov 26, 2010
    Linear and circular polarizers do different things.

    Hoya makes a multicoated circular polarizer. Polarizers are optical gratings and I am unsure if you could coat them or if it would be worth it.

    Graduated neutral density is not very good in a circular mount. You would need a square filter with filter holder so you can control where in the frame the transition is.
     
  5. Ned

    Ned Mu-43 Legend

    Jul 18, 2010
    Alberta, Canada
    46mm filter threads were used on some rangefinder lenses (like Leica), although not as common as 40.5mm. The best place to find filters for a 46mm thread is at camera exchange shops which deal in old cameras. You can also get those metal vented lens hoods for Leica lenses in both 40.5mm and 46mm thread sizes.

    As far as a linear polarizer, those are near impossible to find new anymore now that we're in the digital age. Everybody makes Circular Polarizers instead. However, since you have a filter thread that was used with old lenses, you could of course find old used Linear Polarizers in the same place you can find other 46mm accessories and filters.

    The reason why Circular Polarizers are used on digital cameras is because of Autofocus compatibility. Linear polarizers screw up AF on DSLRs... although I don't know if it does on CDAF. Maybe somebody could answer that question. ;)

    And yes, I agree with Hikari that a square filter holder is much more effective for Graduated Neutral Density. Graduated circular filters just don't make sense. ;)
     
  6. Hikari

    Hikari Mu-43 All-Pro

    Nov 26, 2010
    Ned, spot on about the circular polarizer for phase-detect AF in DSLRs--linear polarizers don't work because linearly polarized light at the right angle will not pass through the focus system. But both should be fine on contrast detection. The linear you can control the angle of the polarized light you want to eliminate. This can be used to control the how much of a reflection you get off non-metallic surfaces.

    Lots of 46mm filters at B&H.
     
  7. ssgreenley

    ssgreenley Mu-43 Top Veteran

    509
    May 12, 2011
    Ya'll make a good point re: circular graduated filters! That was my bad. So, would ya'll recommend just shelling out for the circular multi-coated polarizer then?
     
  8. ssgreenley

    ssgreenley Mu-43 Top Veteran

    509
    May 12, 2011
    Also, thanks for the info!
     
  9. Ned

    Ned Mu-43 Legend

    Jul 18, 2010
    Alberta, Canada
    Linear polarizers have a stronger affect than circular. If you're using a mirrorless camera ad don't need to worry about AF incompatibility, I would stick with the linear. I wish I had a linear polarizer right now, trying to shoot yellow driving glasses on a white background. The light goes right through and removes the yellow lens. The circular polarizer helps, but the linear would be perfect.
     
  10. ssgreenley

    ssgreenley Mu-43 Top Veteran

    509
    May 12, 2011
    Just found a B+W F-Pro linear MRC polarizer on the internets! Thanks again for the help!
     
  11. usayit

    usayit Mu-43 Hall of Famer

    I shoot with Leica and variety of different cameras and lenses of different thread sizes many of which are odd (annoying). Often the best thing to do is pick a common larger thread size, buy your filters at that size, and step up rings to accomodate different threads.

    In my case, I chose 77mm size and 39-55, 46-55, and 55-77 step up rings to accomodate, 39, 46, and 55 filter threaded lenses. Allows me to use one set of polarizer, ND, and Low pass/IR filters at 77mm.
     
  12. Wasabi Bob

    Wasabi Bob Mu-43 Top Veteran

    Quick Question

    I have no intention of trying to hijack this conversation, but I do have a relevant question. I have several very well built polarizers that I purchased 30+ years ago from SPIRATONE. You old timers will remember them, I'm sure!

    My question is, how can I determine whether they are circular or linear. Been using them for years and never had any problems.

    Again my apologies & Thanks

    BTW, I'd consider getting an adapter from 46 mm up to a larger more standard size. Adapters are cheap and the filter can pull double duty.