Infinity focus on PK lens and GF2

Discussion in 'Adapted Lenses' started by otakuma, Dec 30, 2014.

  1. otakuma

    otakuma New to Mu-43

    4
    Dec 30, 2014
    Hi guys. I got a Panasonic GF-2 and Olympus Digital 14-42 lens, no problems with it. However, if I use my Pentax PKtoM43 adaptor with either my Ricoh 50mm or Tamron 24mm lens I can't get infinity focus, no matter how much I adjust the focus. Reading the description of my adapter it says that infinity focus is supported only on focal lengths over 50mm. My question is, if I get another adaptor (from Nikon, Canon, or whatever, you tell me which is best) and the respective 35mm or 50mm lens, will I be able to get infinity focus?
    I've read many posts here but I still haven't managed to understand the issue. Thanks :)
     
  2. RDM

    RDM Mu-43 All-Pro

    If you can't get Infinity with your Ricoh 50mm, then you should exchange it for another, they usual will guarantee it will work with a 50mm lens, since that's what they designed them with. Unless your lens is defective.
    Does the Lens work on a film body?

    I would guess the adapter might be defective.. . they make thousands of them with little or No quality control in China, and you will hear the occasional tale of an adapter that didn't work, on various message boards.

    I have a Minolta MD adapter that works on all my lenses even the vivitar 17mm. My Canon FD adapter works with the Canon 50mm lenses that I have as well as a 3rd party 28mm lens in FD mount.
     
  3. otakuma

    otakuma New to Mu-43

    4
    Dec 30, 2014
    Thank you. I don't care if the adapter is faulty, I still won't be able to get infinity focus under 50mm and I wanted a 35mm lens.
    Do you recommend an MD or FD adapter then? Which lens should be cheaper on the market? I'm probably gonna sell my 24mm and my 50mm to get a 35mm and maybe 50mm that works with my GF2 with infinity focus.
     
  4. HarryS

    HarryS Mu-43 Top Veteran

    920
    Jun 23, 2012
    Midwest, USA
    The focal length of the lens does not matter, To get infinity focus, a Pentax mount lens can be no more than 26.2 mm away from the mount of an M43 camera. An adapter must be less than that length. I have a PK and a DA adapter. They measure 26.0 -26.1 mm. I also have a few M42 adapters. They are also that length. My Pentax mount lenses, which include a DA 16-45 all can reach infinity,

    Your adapter is too long. Get a different adapter made by someone else. The ones I buy are cheap.

    Edit. If you are talking about a focal reducing adapter, one that has a lens inside it, then the above does not apply.
     
  5. otakuma

    otakuma New to Mu-43

    4
    Dec 30, 2014
  6. dwig

    dwig Mu-43 Top Veteran

    623
    Jun 26, 2010
    Key West FL
    True for exact infinity focus, but...

    ... any error in the thickness of the adapter will create an error in the infinity focus setting inversely proportional to the focal length. A small error may be unnoticeable on a 50mm lens but will be significant on a shorter lens.

    The trend on the inexpensive adapters is that they have little or no quality control and that they very a good bit sample to sample. As a rule, it seems that the smarter manufacturers target a thickness that is slightly thinner than the mount specs indicate. This means that when they hit their target the lens will focus past infinity allowing you to achieve infinity focus. When they miss and produce a slightly thicker sample you still may be able to reach infinity if the error is modest. To date, all of the adapter I've purchased (all less than $30) are a tough too thin and my lenses focus slightly past infinity.
     
  7. RDM

    RDM Mu-43 All-Pro

    You are kinda missing my point ..
    I was explaining that most people DO get Infinity focus with their adapters because you should; for reasons already mentioned by harry.
    I was suggesting a return because the companies just will not exchange the adapters for fault of no infinity focus for lenses that are under 50mm because that is what they test them for.

    OK you see its like this,.... there is usually some focus beyond infinity for longer lenses.
    NOW, where most adapters are made, the Tolerances for them are not that strict at these Chinese factories. Wish they were all like the German brands..
    Like Harry said , "a Pentax mount lens can be no more than 26.2 mm" and more than likely they designed their adapters to be 26.15mm or 26.1mm to allow room for error knowing there most likely will be errors. So if the casting processes gets screwed up three or four times out of a hundred then there are hundreds of adapters that are too thick or too thin coming off the line, now there should be someone checking to make sure those defective ones do not get by, and that is what I meant by quality control are not strong there. However I think the numbers of errors from the ideal mold are allot higher but they allow a much thinner or thicker mount to pass.. That is what tolerances is, and the shorter than 50mm lens would not have enough extra throw to focus to infinity, if there mount was .. lets say 26.21mm. But the longer lens would work ...
    SO they make the guarantee that the mounts work for 50mm and up and that way they have less to recycle at the plant and save manufacturing costs and can sell cheep mounts..

    SO you either exchange that mount citing that your 50mm lens wont focus properly on it, buy another mount.. because they are soooo cheep .. and see if that is Better; Or you get a a more expensive brand that is made to higher standards.. I think the best might be Novoflex, but they are expensive.

    If I was asked to mention the best brands of adapters, that I know of, which are sold today, that are high or very good quality, I would say look at NovoFlex & Voigtlander (which is pretty much the same as Novoflex in quality and price) and on the lower price end there is Metabones and Kipon.

    I can tell you now that I too am thinking of a better quality adapter for myself, due to many other reasons other than infinity focus, and I believe the best in terms of over all quality to price ratio is a Kipon brand adapter.. Novoflex is reputed to be the best, but I don't have that kind of money to throw down...lol
    I do also like the release button on the metabones adapter better, and it is only about 20% more, but it has a tripod mount that I do not think is removable.
     
  8. RDM

    RDM Mu-43 All-Pro

    I have the same problem. I was looking to see if someone made and sold shims for them but I have not found any. I also would love to find an adapter with the µ4/3 bayonet as a removable (screwed on) piece, instead of being cast as part of the barrel. That side would be easier to shim I expect. Unfortunately I have only seen exotic adapters made this way.
     
  9. Petrochemist

    Petrochemist Mu-43 Top Veteran

    652
    Mar 21, 2013
    N Essex, UK
    Mike
    I don't see focusing slightly beyond infinity is a problem. Most long lenses do it on their native mounts to allow for thermal expansion.
    I know it will increase the close focusing distance too but that will generally be a fairly small change.

    A couple of years ago I brought a µ4/3 to M42 adapter that had a helicoid built in. Such a shame they made it 0.1mm too long for infinity focus! I'd also much rather had had a PK version (which can be adapted to M42) but AFAIK that's not made at all.
     
  10. otakuma

    otakuma New to Mu-43

    4
    Dec 30, 2014
    No, I do get your point, but since I bought this adapter for 10€*over a year ago, the return is simply not possible (and it will probably cost me more than buying another one).
    I went on both Metabones and Kipon website and I didn't find any PK to M43 adapter, but their price range from 99$ to 400$, which is simply too much for me, since I'm using cheap lenses anyway. The best for me is to probably get another adapter for a little bit more, like 20$, and hope it's better built.
     
  11. pellicle

    pellicle Mu-43 All-Pro

    Feb 10, 2010
    Southport, OzTrailEYa
    pellicle
  12. HarryS

    HarryS Mu-43 Top Veteran

    920
    Jun 23, 2012
    Midwest, USA
    It's not hard to make tha adapter a little longer if you are rotating the barrel well past infinity. Use aluminum foil duct tape. It's aluminum foil with an adhesive backing on one side. My best guess is that it runs about ,05 mm in thickness.

    -Take the plate off on the lens side, usually held by three or four phillips head screws. Most adapters have no moving parts, but some like the FD take more care.
    -Add tape to back of plate and replace. Add more tape if needed for further shimming. Probably need two layers to see much difference.

    Making it thinner, as in the OP's case, requires a machine shop, if his adapter is like my PK adapter, The adapter plate on mine is very solid and heavy, The barrel is soft aluminum, and if I had access to a machinist, I'd ask him to trim the inside rim of that barrel on his lathe.
     
  13. pellicle

    pellicle Mu-43 All-Pro

    Feb 10, 2010
    Southport, OzTrailEYa
    pellicle
    Except you need to make it shorter, which is why I lapped mine down as above.

    As the problem is (as I understood it) the OP can not get to infinity. These lenses focus by extension and thus adding length would bring focus further away (as in the manner of operation of extension tubes operation)


    The FD back of plate you mention can also be lapped down carefuly with emery paper to achieve the desired outcome (as I have done with a few cheapie FD adapters.
     
  14. Klorenzo

    Klorenzo Mu-43 All-Pro

    Mar 10, 2014
    Lorenzo
  15. Petrochemist

    Petrochemist Mu-43 Top Veteran

    652
    Mar 21, 2013
    N Essex, UK
    Mike
  16. Klorenzo

    Klorenzo Mu-43 All-Pro

    Mar 10, 2014
    Lorenzo
    Yes, you are right, I suppose. The page is quite confusing but I think that is the reason. Thanks.