My dad has an old Sears KS-2 + 50mm f/1.7, which from a bit of research seems to use a Pentax K-mount.

I've looked around a bit and found a Pentax to Canon adapter, which says it supports af-confirmation, and costs ~$30 US.

Has anyone tried using an adapter ring like this, and if so, would you recommend doing so?

I am perfectly happy with shooting manual, but I'm curious about the quality of older lenses. I'm assuming that if I use older primes the optical quality will be fine, and it looks like the build quality of the older lenses is much better that similarly priced new lenses.

  • \$\begingroup\$ 50mm f/1.7 is a fine lens, if you want some user opinions on it, pentax forums has a lens database here: pentaxforums.com/lensreviews \$\endgroup\$
    – Joanne C
    Commented Dec 13, 2010 at 20:47

2 Answers 2


I use an older Pentax 50mm f/1.7 on my 60D and get spectacular results. I have the exact adapter shown in your post and it works great with barely any play between the lens and body.

The only problem with old glass is that it typically has poor handling of flare so be mindful of light sources and use a hood.

  • \$\begingroup\$ Great to hear! Have any recommendation on a hood? \$\endgroup\$
    – chills42
    Commented Dec 13, 2010 at 20:31
  • \$\begingroup\$ Depends on your preference, I use a pretty generic rubber hood for my 50mm and it does OK at really off-axis flare but it isn't the best (and doesn't help much for protecting the front element). \$\endgroup\$ Commented Dec 13, 2010 at 22:15

Bear in mind that the aperture will usually have to be set manually too. So you focus first, then stop down, then meter (if required) and shoot. The intermediate step can be a bit of a hassle, depending on your subject matter and the light levels. But otherwise it should work fine - I have a couple of Pentax and Zeiss lenses that I use on my EOS cameras with decent results.


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