Wednesday, November 02, 2011

Focus Calibration

I'd been using my Leica M8 with a Voigtlander Cosina Nokton 50mm f1.1 for portraits and headshots for the past few months with great results. I'd shoot at f1.4, and it would really pull the subject away from the background.

Then last week, I snapped some new headshots of a COO, and when I flipped back through them, they were blurry. Instead of his eyes being sharp, his ears were sharp.

I thought maybe I screwed up the focus, so I just scheduled a re-shoot. Fuzzy again. I switched over to my Nikon D7000 with a sick feeling in my stomach.

I did a quick focus test in my office. Here's a crop of my results.

BackFocus

I was focusing on the center dart. The Nokton was suddenly giving me at least an inch of back focus at f1.

I ran the same test with my other lenses. The 28mm Ultron and the 90mm Elmarit checked out ok, but the 135mm Elmarit was also back focusing.

I only found one place in Houston that works on Leicas, Professional Camera Repair, located on Richmond Avenue.

I made a run over there at lunch, and the owner took a look at my lenses. He warned me that the Nokton was known for having a factory defect that caused back focusing. I assured him that it was working correctly just a week ago. He said that since my other lenses were focusing correctly, he didn't need the M8 and that he would check the 50mm and the 135mm and let me know what he found sometime next week.

I guess a week is better than three months in Solms.
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