tom5 Posted July 13, 2007 Share Posted July 13, 2007 I bought a Contaflex 35mm f/3.2 lens at a sale, even though I don't have a contaflex. The lens looks really pretty and is very clean. I can't figure out if the focus adjustment is broken or not. The focus ring on the rear of the lens rotates smoothly around 360 degrees but nothing seems to happen inside the lens. Hmmm .. then I thought that perhaps the focus scale locks in place on the camera body. However, there isn't any notch or indexing system on the rotating focus ring at the rear of the lens. I'm suspecting that the focus mechanism is broken inside the lens but if this isn't the case, I'd like to know. Any Contaflex users out there? Thanks. Link to comment Share on other sites More sharing options...
kevin_travis Posted July 13, 2007 Share Posted July 13, 2007 That's not a focusing ring, but a depth-of-field indicator. Contaflexes are leaf-shutter cameras, and the interchangeable lenses that are available for them substitute only for the front element of the standard 50mm (or, depending on model, 45mm) lens. The rest of the lens elements, plus the shutter, diaghpram, and focusing mechanism, are permanently affixed to the camaera and are not changed when the front element of the lens is changed. However, different focal-length lenses provide different depths of field, and because the regular depth-of-field indicator for the standard lens is on that part of the lens assembly that is permanently affixed to the camera, it becomes inaccurate when one of the interchangeable front elements is installed. Thus, each of the available interchangeable elements (35mm, 85mm, and 115mm) has the dial you're asking about, which shows the depth of field for the entire lens assembly once that particular front element is attached to the camera. You simply line up your focus distance (in meters on the red scale of the moveable ring, or in feet on the white scale of the moveable ring) with the fixed white arrowhead on the lens barrel, and then read down from the red f/stop numbers on either side of the white arrowhead to see what the correct depth-of-field is for that particular front element. The numbers on my 35mm front element are not that much different from the ones on the focusing mount of my Contaflex BC for the standard 50mm front element, but the numbers are significantly different for the 85mm and 115mm front elements. Hope this helps clarify the use of this ring. Link to comment Share on other sites More sharing options...
tom5 Posted July 13, 2007 Author Share Posted July 13, 2007 Thanks for the prompt answer! I should have figured that out about the depth of field indicator. The lens is a real beauty and I have the original front cap and back of the bubble. I don't have the "bubble" part of the case, however. Link to comment Share on other sites More sharing options...
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