Focus Fix For Non-reflex 35mm Camera

For camera fanatics the acquisition of an old camera is a thrilling event. But if you’re going to collect them, you’d better have some repair skills so that you can also use them. [Fernando’s] latest find was this Minox 35mm camera. The aperture needed cleaning, and after reassembling the unit he realized the he had not marked the focus ring when taking it apart. This is not a reflex camera, so you can’t look in the view finder to adjust focus. He came up with his own method to get the focus ring calibrated.

The focal point needs to focus on the film. He simulated this plane using some magic tape, which removes easily without leaving a residue. When the shutter is open, you can see the image projected on this translucent surface. He then set up the camera with the lens 90 cm from a bright light bulb. By adjusting the focus to create a sharp image on the temporary screen, he knows the focus is calibrated, and can reset the focus ring to the 0.9m mark.

Need some help developing that exposed film? You could always give the coffee and vitamin C hack a try.

5 thoughts on “Focus Fix For Non-reflex 35mm Camera

  1. Some days, it’s easy for photographers to forget that everyone doesn’t know about using a ground glass focal plane.

    But, then again, I forgot to put threadlock on the stop screw of a very nice Zeiss lens. No idea where that sucker bounced to.

    1. That’s why you need either a dog, or small children.

      Both are amazing at zooming right in to where the lost part landed (even if they weren’t in the room when you lost the part), even in shag carpeting. Once you see it, you’ll swear they use magic.

      Of course then your problem shifts from finding the part, to trying to figure out how to make the dog or child spit the part out of their mouth.

  2. This is great info – I often wondered what would be the solution if the focus was inaccurate on a camera like this. Would it not be better to focus on a distant object, assuming the lens has a hard-stop infinity focus, than introducing a slight error by guessing at the exact location of the 0.9 m mark?

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