|I can make a dual range summicron out of anything!
||[Dec. 25th, 2014|09:49 pm]
|||||andrea schrode: helgen||]|
TL;DR / not a photographer; don't care:
I've discovered that if you shove a penny in between a 50mm Leica Screw Mount lens and the adapter, you can focus to about .63 meters, instead of the 1.00 meters that it was designed for.
The elegant explanation
When I went to high school there was this guy who wanted to be an engineer who was fascinated with muscle cars and he bought ... an AMC Gremlin -- I don't know if you know what an AMC Gremlin was, but it was EXACTLY the polar opposite of a muscle car. And when one of our classmates chided him about his purchase of this really ugly, really low-power car, he said "I can make a GTO out of anything."
For those of you who weren't around in the 1980's, GTO stood for "Gran Turismo Omologato" which was a class of super-powered racing cars. And true to form, he was out in his driveway every day after high school boring out the engine and adding hood-scoops and superchargers and whatever else until he had the most powerful, fastest car of anybody in the entire high school and he'd tear around the parking lot laughing out the window at the kids with the primer grey Chevy Nova's challenging them to a drag race.
This has almost NOTHING to do with what I'm talking about.
You can actually close focus any Leica screw mount lens to about .65 meters
with no real hassle. Clickenzee to emiggen!
Eeking out that last bit is very expensive
When the first Leica cameras came out, their close focusing distance was one meter. Which isn't very close. And to me, that close focusing distance is one of the big, and very important, things that separates a Leica from an SLR -- SLR lenses focus a lot closer (usually about .45 meters)
Leica countered this with the Dual Range Summicron, which is (like many Leica things) a bafflingly complex lens system with lots of extra whatnots goggles. It allowed you to focus a 50mm lens to something like .45 meters.
This is important because depth of field is determined by not just aperture, but distance to the subject, so, if you're looking for a very shallow depth of field (something often prized in photography), you want a wide aperture, and you want to be close to your subject. (There's a whole discussion on this if you don't understand it. But the take-away is that lenses that can focus closer are more useful.)
Years ago I bought a really cheap 50mm lens in "Leica screw mount" -- it was made by Canon back in the 1950's and it focused to 1 meter and it was way less expensive than a modern Leica lens. Very recently I'd been thinking that I should upgrade that to a newer lens because the new ones focus to .65 meters. I kept looking at new lenses and found myself thinking that the only reason I wanted to change anything was because I wanted to focus closer to get tighter headshots and a shallower Depth of Field.
I knew the camera was capable of focusing closer, and when a screw fell out inside my lens earlier this year, I learned that lenses were prevented from actually focusing closer by a screw stopping them. If the lens was farther from the camera, I wondered, wouldn't it focus closer? -- this isn't new thinking, it's the rational behind closeup tubes. But, as far as I knew, nobody made closeup tubes for focusing a Leica Screw Mount lens just a little closer -- typically they're used in macro-photography.
What if I just separated the lens from the body a little bit? Within the tolerances of the screw-mount adapter and the lens itself? As long as the Focus Coupler could still touch the lens, with a 50mm, you should still be able to focus it to these closer distances.
I yearned to try it with something easily available. I started to unscrew the lens from the adapter to see how far I could get it out before the rangefinder coupler wouldn't touch the lens anymore, and then I started trying to jam common objects into the space created: paper clips, credit cards, etc. Imagine my surprise when an ordinary penny seemed to get pretty close to the closest possible distance that still coupled the rangefinder.
Unscrew the lens, shove a penny in the gap, screw it back.
From the side, it looks like this -- the tiniest extension tube you can carry in your pocket:
There you go.
It's not as close as a Dual Range Summicron, but it's not as expensive and it works with any 50mm Leica Screw Mount Lens -- so you can buy one of those Voigtlander Noctilux's and close focus it ... for a penny.
Think this is cool? Think it's blasphemy? Feel free to fight it out in the comments. Or share it, repost it, reference it, pass it along. This is free. Have a question? Ask it.
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