Got to visit New York last week, more specifically Manhattan. I took along my Pentax k1000 and two Pentax lenses. The 50mm f/2 stayed on the K1000 but the modified 55mm f/2 Pentax lens was used on my Canon 6D along with a 17mm-40mm and a 50mm f/1.4. Even though I’ve modified both Pentax lenses to work on the 6D I think the 55mm is a little sharper and decided to leave it on the Canon. I also picked up a 52mm threaded lens hood for the 55mm.
All Pictures were taken with a Pentax k1000 using Ilford 400 Black and White film and a 55mm f/2 Pentax prime lens. I must apologize as I didn’t write down the settings I used. I first metered the shoot as I would take it with my Canon 50D at 400 ISO and then duplicated the setting on the Pentax but didn’t think to take notes. The digital scans were adjusted some in Lightroom for brightness and contrast but if there are some unspoken rules about not editing your film scans in post, complain to someone else.
First things first, attempt this modification at your own risk. If you break something or yourself don’t come crying to me.
I recently was given an old Pentax lens and wanted to use it on my Canon Cameras. Now, for APS-C Canon DSLR’s like the Rebel line this is not much of a issue. Purchasing a simple Pentax to EOS adapter for a few bucks makes this happen. However, If you want to use it on the the 5D or 6D Cameras you should stop before attaching the adapter. This is because while the Crop Sensor Cameras work fine, Full Frame Cameras like the 5D, 6D etc. have a larger mirror that will hit the Aperture lever/guard on the back of the lens. The solution? Simply put, cut off the Lever and Lever Guard. Now if you’re the live-life-dangerous type just Dremel the dang thing off and be done with it. But….If we can find the obsessive-compulsive with-in, we’ll need get a little more complicated and partially disassemble the lens and do it “Right”. Or At least what I would consider “right”. Partially disassembling will allow cutting off the parts needed with little risk to the lens.
Downsides to modifying an old Pentax lens like this? Value of the lens is now suspect, as its only valuable to you and other Canon users looking to do the same thing. That said, if you reattach the modified lens to an old Pentax film camera the camera it will still work. You’ll still be able to take pictures like before but the camera will act like its always got a dept of field preview button pressed. This wont effect the pictures but will darken the viewfinder at higher f-stops. This happens now because the lever that was there before you so rudely cut it off allowed the camera to keep the aperture open all the way till the moment the shutter opened. This was to let the maximum amount of light into the viewfinder so you could see what you taking a picture of. Now If you stop the lens down you’re not only limiting the light going to the film but also the viewfinder. Again this wont effect the picture, just what you see though the viewfinder. Incidentally, this is also how it will work on your Canon camera as well.
6/27 Update: I got a chance to try this adapter out on some other Canon SLR’s. I found that the conformation chip on this particular adapter was not compatible with the T4i, T5i and the SL1. Not only was the chip not compatible, it prevented the cameras from working. The chip did not hurt the Cameras, it just put them into an error mode that went away when the chip was removed. As for my 50D and 6D I’ve experienced no errors and the lens and conformation chip work great.