M42 to EF adapter with chip, and allows auto/manual

Discussion in 'Canon EOS' started by davemoss, Jan 13, 2021.

  1. I tried to be as specific in the title. I'm looking for an M42 to EF adapter that has both the chip (to allow for focus beep) as well as having the proper flange to not depress the pin, allowing for the auto/manual slider to properly function on SMC Takumar lenses.

    thanks for any suggestions.
  2. Shouldn't the pin get hit by something else inside your EOS, if at all? M42 adapters I have seen so far looked see through; i.e. just the thread, nothing pin hitting.
    I hope you own a pretty cheap camera to check out if your chip is safe. (<-Copied paranoia.) - I should buy one to test my chipped k-mount adapter.
  3. Be aware that if the little glued-on focus confirmation chip is not placed correctly it can short things out on the camera ( long ago post, but still valid WARNING on Focus Confirmation Adapters damage to electronics). Unless you have real eye problems, just trust your eyes, the little pirated circuitry doesn't really work well even when it works.
  4. M42 lenses come in several varieties.

    Preset ones - with no auto pin.
    Switchable Auto - where there is a shut down pin but a switch on the lens disables it
    Unswitched auto - where the pin must be pressed for the lens to stop down.

    Canon cameras have no interactions with any of these, but the lens will work fine in fully manual mode if mounted by a suitable adapter.
    Many adapters have a small flange to depress the pin & allow use of the later unswitched lenses. If I remember correctly all M42 lenses will stop down when used on a flanged adapter - so most adapters now come with the flange.

    A little work with a file or dremmel tool can remove the flange if it's a major inconvenience, if you can't find any sold without it.

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