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I can make a dual range summicron out of anything! - if you can't be witty, then at least be bombastic [entries|archive|friends|userinfo]
kyle cassidy

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I can make a dual range summicron out of anything! [Dec. 25th, 2014|09:49 pm]
kyle cassidy
[mood |accomplishedaccomplished]
[music |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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Comments:
[User Picture]From: daddygod
2014-12-26 03:35 am (UTC)
Our family car was a Gremlin in the mid 70's.
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[User Picture]From: kylecassidy
2014-12-26 03:40 am (UTC)
I hope you're happy now to know that you could have made it into a supercar with a drill and a lot of dedication.
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[User Picture]From: daddygod
2014-12-26 03:45 am (UTC)
I was seven.

All I remember is the emblem on the gas cap.
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[User Picture]From: moon_chylde
2014-12-26 03:51 am (UTC)
OMG why do you post something like this that feeds my camera geek when I'm too messed with "Christmas cheer" to appreciate it? LOLOL

Will get back with it tomorrow.
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[User Picture]From: kylecassidy
2014-12-26 03:54 am (UTC)
Luckiy, it ought to make your camera geek less expensive. You can get a LTM 50mm for $50 (if you want to get a russian lens with the f-stops on backwards).
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[User Picture]From: moon_chylde
2014-12-26 06:29 am (UTC)
Danke
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[User Picture]From: sheilagh
2014-12-26 05:57 am (UTC)
aside -- where did you get those fabulous ac-kitty icons??

signed covetously,
Sheilagh
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[User Picture]From: moon_chylde
2014-12-26 06:22 am (UTC)
Go here...

http://www.actioncat.com/

Then go to Holidays/Seasons Those are all just purrrfect for icons. Enjoy!
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[User Picture]From: sheilagh
2014-12-26 06:39 am (UTC)
<3

>'.'<

tyk!
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[User Picture]From: batwrangler
2014-12-26 04:28 am (UTC)
My dad had an orange Gremlin with yellow go-faster stripes. He was also on our small-town police force. This sometimes resulted in interesting conversations between dispatch and new police officers in neighboring jurisdictions: "Why is there an orange Gremlin speeding through town with a blue light?"

Ps. Neat trick with the penny!

Edited at 2014-12-26 04:32 am (UTC)
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[User Picture]From: thebiblioholic
2014-12-26 08:04 am (UTC)
Excellent!
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[User Picture]From: dd_b
2014-12-26 04:44 pm (UTC)
Cool, not blasphemy. (Extending a lens does stress the image quality some, and some lenses do better than others, but that's just as true using extension tubes or a bellows for macro photography; you have to choose your lens suitably.) I don't actually know a single good photographer who has any "perfect" pieces of equipment; they tend to have pieces of equipment that they understand in tremendous depth, and use in ways that let them make the pictures they want.

A boss at an early job had a car we called his "Ex-Gremlin" (around 1975). He bought a brand-new Gremlin X, pulled the engine and transmission (cheapest manual), and installed a big-block V8 and a special racing automatic transmission. The battery ended up in the back window (no room under the hood). The clutch pedal was still there, free-floating. He normally drove an old VW beetle, but this was his toy car.
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[User Picture]From: kylecassidy
2014-12-26 05:13 pm (UTC)
This is, though, exactly how far the lens would move out if the helical extended far enough to focus to .7 meters, right? as it does on the new lenses. So shouldn't the stress be identical to a more modern version of the lens without the focus limitation screw and a notched helical?
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[User Picture]From: dd_b
2014-12-26 07:08 pm (UTC)
Yes, definitely. And small extensions like this rarely have drastic effects on image quality (can't think of an example).

Are the new lenses that focus closer identical optically? If so, then yeah, you're getting the same optical results, just not quite as conveniently (and much more cheaply).

(Anyway, if the results meet your standards, then they meet your standards, and I would presume also meet mine, not that you need to meet mine anyway :-) )
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[User Picture]From: i_love_tazzus
2014-12-26 06:25 pm (UTC)

Cool hack

Love it. Could this be done with a bayonet mount system?
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[User Picture]From: kylecassidy
2014-12-26 06:57 pm (UTC)

Re: Cool hack

No. There's no way to gradually remove the bayonet mount, and when you did, light would leak in.
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[User Picture]From: lawbabeak
2014-12-27 04:33 pm (UTC)
Well, MacGuyver, you did it again!

I love gerry-rigged but effective solutions. Like how I held my Birkenstock together for YEARS with duct tape, or how my dad fixed Oma's card shuffler with a toothpick and some thread.

You rock.
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[User Picture]From: kylecassidy
2014-12-27 05:35 pm (UTC)
This isn't gerry-rigging, THIS IS AN INCREDIBLY WELL CRAFTED ZINK AND COPPER CAMERA PART MADE TO EXTREMELY EXACTING SPECIFICATIONS.
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[User Picture]From: serialkiller
2014-12-27 10:52 pm (UTC)
kyle, did you ever share how you came to retrieve your stolen leica?
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[User Picture]From: kylecassidy
2014-12-29 03:22 pm (UTC)
I'll probably have a massive blog post after the sentencing but I don't want to do anything right now that could influence the trial.
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[User Picture]From: serialkiller
2014-12-29 06:31 pm (UTC)
I had a feeling that may be the case. Well in any event I can't wait to hear all about it when the time comes... cause that is some serious luck you have sir. So good you got it back!
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[User Picture]From: kylecassidy
2014-12-29 07:44 pm (UTC)
There was no luck involved -- all serious detective work! It's very interesting!
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