Sears 2x and 3x converters (M42) questions.

Discussion in 'Adapted Lenses' started by John_Dear, Dec 30, 2011.

  1. John_Dear

    John_Dear New to Mu-43

    Nov 29, 2011
    I've had a lucky few days thrifting and got some new toys to go with the M42 adapter I bought myself when xmas shopping. Best item was the Sears 55mm f1.4 in great condition that I found attached to a very old Sears T.L.S. with a dented pentaprism. (The camera looks like the 1967 Ricoh T.L.S., does that mean that my lens is Ricoh too, or are all the Sears f1.4 made by Tomioka?)

    Today, I found 2 Sears branded tele converters that are also in great shape, but I don't know exactly how they're used.

    a. Can they be stacked to get even more "tele"?
    b. How do I use the aperture ring on the adapter? Should that aperture ring just be turned to match the lens?

    Thanks for your help.
  2. harrysue

    harrysue Mu-43 Regular

    Mar 12, 2011
    Yes, your two teleconverters could be stacked to get a 6x multiplication, so that 55mm will see like a 330mm, at least in theory.

    Teleconverters have light loss. A 2X teleconverter costs you two stops. So your f1.4 lens now is f2.8 at best. Stacking an additional 3X teleconverter will probably knock it down another 3 stops, down close to f8.

    The second tradeoff is that most legacy teleconverters degrade image quality. I would expect these old ones work best as door stops, but who knows. Try them out and see what you get. These things were like $20 when they were new, so you cannot expect them to be as good as a $500 modern converter like the Olympus EC20 (for 4/3 SLR's).

    I can't picture why an M42 teleconverter would have an aperture ring so no help here. I guess you just make sure the aperture ring on the lens is working after the combo is screwed into your adapter.

    EDIT: I decided to try my legacy 50mm lenses where I had teleconverters available on my EPL1. I must retract my comments about door stops. The poor results I recall from my film days doubtless included camera shake and trying to shoot wide open in poor light. Mounted on tripod, with IS turned off, and primary lens stopped down to f4, the results were reasonable to me, given what I paid for the converters.

    An OM F.Zuiko 50mm f1.8 on an EPL! with/without a Tokina converter, both at F4. The converter required a 1/20 second exposure, which illustrates the speed tradeoff.
    <a href="" title="Oly_f4 by munque, on Flickr">"500" height="375" alt="Oly_f4"></a> <a href="" title="Oly_f4_2x by munque, on Flickr">"500" height="375" alt="Oly_f4_2x"></a>