Conversion pieces for old M42 thread lenses

Discussion in 'Canon EOS' started by clipper, Jan 22, 2006.

  1. I am quite new to digital photography. I have just purchased a Canon
    350D and I wonder if I can still use my old lenses (tele and zoom)
    by using a conversion ring to connect the M42 thread of the lenses
    to the Canon body.
    Is it at all possible?
    I realise I will lose the AF funtionality of the camera.
    Will any other function be lost, such as auto setting of aperture
    and speed by the camera?

    Can it in anyway damage the camera?

    Any advise will be greatly appreciated!
  2. Yes, you can get an Adaptor.

    You lose AF, shutter priority. program (And all 'Basic Modes') and A-DEP, as well as
    evaluative metering.

    Metering is stop-down in Aperture priority or Manual, with centre-weighted or partial
    metering (Bodies which support spot metering can use that as well). E-TTL 2 flash will
    work fully in Manual or Aperture priority modes (No auto aperture setting but it will
    expose for your settings). You will lose focus confirmation.

    Look for an adaptor with a ridge on the back, which will engage the auto-aperture pin.
    Auto-Aperture on A/M M42 lenses will not work, they need to be set to manual aperture.

    You may have difficulty focusing, the small and dark viewfinder in the 350D is not well
    suited to manual focus and will likely be unusable if the lens is slower than f2 or so.
  3. I use a variety of M42, Pentax-K and Adaptall lenses on my 20D, and I plan to do the same for Nikkor, Carl Zeiss (Contax) and Leica R in the future. I suggest that you read Using manual lenses and telescopes with EOS cameras. Also, you should be aware that some of the more recent versions of SMC Takumar lenses should not be used with adapters with a rim or "ridge on the back" for the auto-adapter pin, as they also grind against the aperture index lever, as discussed in this past posting on M42 adapters on EOS cameras.
  4. See also:

    M42 lenses work fine on EOS bodies.
  5. And if you are desperate to pop K or KA mount lenses on your Canon, there is this, the EOS K mount:

    Granted, it's a custom, hack job, but I've seen results from this combo and it works.

  6. Jon describes a permanent solution from SRB Film Service in the UK, where the old Pentax-K mount is cut off and replaced by a new EF mount. I use a different solution that I call the Keos adapter, which is often listed on eBay by user Mr.Rolfo (see recent sale of item 7563927830). The Keos adapter fits over the existing K mount and is kept in place by a small set screw, and so it can be put on the lens and taken off in the same way as a M42 to EOS adapter (except for the extra step of undoing the set screw). In both cases (SRB and Keos), any Pentax K-mount lens with an automatic aperture (i.e. most K series, all -M, -A and newer series) has to be permanently modified by removing the aperture control lever, as it sticks out too far to fit inside the EOS body.
  7. Thanks to everyone for the answers and links. All very helpful.
  8. I use/have_used a m42 converter for my 500/8, 135/2.8, 200/3.5 lenses on both my 350D & 300D. Works fine on Aperture priority. Focus is not a problem even stopped down a big. The 500/8 mirror lense only transmits the equiv of f10 or f11, but it's not that hard to focus.
  9. I'd like to add to the comments on using K mount lenses on EOS-
    <P>It has recently been discovered that unmodified K mount lenses can be used on Digital EFs compatable bodies (i.e 300D/350D/20D).
    <BR>this is because the EFs cutout inside the mirror box neatly accepts the protruding K mount lens bits.

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