{"id":22,"date":"2008-04-14T04:30:00","date_gmt":"2008-04-14T04:30:00","guid":{"rendered":"https:\/\/skeggs.org\/wp\/?p=22"},"modified":"2008-04-14T04:30:00","modified_gmt":"2008-04-14T04:30:00","slug":"vivitar-k-mount-lens-with-pentax-digital-slr-k100d","status":"publish","type":"post","link":"https:\/\/skeggs.org\/wp\/?p=22","title":{"rendered":"Vivitar K mount lens with Pentax digital SLR k100d"},"content":{"rendered":"

Old manual focus lenses are super cheap, and very compatible with current Pentax digital SLRs.
Because the CMOS sensor in digital SLRs are not as larger as a 35mm film cell, you end up with the lens delivering 1.5x the focal length it would on a film camera, which is kind of nice on a telephoto lens, but a hassle with wide angle.
Anyway, some old Vivitar lenses won’t fit on new Pentax digitals, the little guard for the aperture pin is too wide. I got myself a very cheap ($20!) Vivitar 70-210mm zoom off ebay, and needed to trim down the guard so it would fit.<\/p>\n

1) here is a pic showing the enlarged guard. The kit lens with my k100d is about a third the length, only a centimeter or so.
I am going to cut the guard back to just after it reaches its full height.<\/p>\n

\"\"<\/a>2) Remove the two *tiny* screws that hold the ring in place. Don’t lose them!
You might want to do this in an environment less dusty than my workshop, but I like to live dangerously.
\"\"<\/a>3) Clamp the ring securely in a vise. Be careful, the metal is quite brittle and more likely to snap than bend.\"\"<\/a>4) Carefully saw away the superfluous guard metal. I found the waste piece easily snapped off when the cut was long enough. It is necessary to support the ring while you are sawing – I held it firmly with my fingers next to where the blade was cutting. I also only used the draw stroke so the cutting was more gentle.<\/p>\n

\"\"<\/a>5) Re-attach the ring. You can see the silver arc where the guard was cut away. I was intending to file the rough edge, but it is not too bad, so didn’t bother. Now would be the time to find the screws you lost earlier.<\/div>\n

\"\"<\/a>7) All done. Here are some snaps showing the zoom range:
\"\"<\/a>\"\"<\/a>
For more details on using manual lenses with Pentax digital SLRs see here<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"

Old manual focus lenses are super cheap, and very compatible with current Pentax digital SLRs.Because the CMOS sensor in digital SLRs are not as larger as a 35mm film cell, you end up with the lens delivering 1.5x the focal length it would on a film camera, which is kind of nice on a telephotoRead more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[],"_links":{"self":[{"href":"https:\/\/skeggs.org\/wp\/index.php?rest_route=\/wp\/v2\/posts\/22"}],"collection":[{"href":"https:\/\/skeggs.org\/wp\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/skeggs.org\/wp\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/skeggs.org\/wp\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/skeggs.org\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=22"}],"version-history":[{"count":0,"href":"https:\/\/skeggs.org\/wp\/index.php?rest_route=\/wp\/v2\/posts\/22\/revisions"}],"wp:attachment":[{"href":"https:\/\/skeggs.org\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=22"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/skeggs.org\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=22"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/skeggs.org\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=22"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}