Found a vintage Nikon bokeh meter, but need manual.

<p>So, I was looking through the dusty old camera gear at a recent abandoned storage auction, and came across a taped up box labeled "Assorted Nik Stuff - M. Johnston." Feeling lucky, I bought the whole box for $10, in hopes of finding a gem or two. Sure enough, in with the old lens caps and dry-rotted leather camera straps, was one of the very sought-after early vintage Nikon bokemeters. This looks like one of the hand-made ones built in Japan for the US market - one of the ones that actually reads +/- 50 micro-B. But I can't be sure on the scale without reading the manual. So, if anyone knows where I can track one down, that would be great.<br /><br />As you can see, this has been pretty well cared for, and the F-mount hardly has any corrosion.</p><div></div>

<p>When I mount an original Nikkor-Q 135mm prime, I'm getting a perfectly neutral reading on the meter, which is similar to my experience with that lens. Fairly nice background blur, but still some funky highlight artifacts when it's wide open.So, it makes sense that it's a wash, and meters out at zero.</p><div></div>

<p>On a hunch, I tried a more recent vintage Sigma 50/1.4, which is well known for its creamy, hypnotic blur and the ability to make any pet portrait look perfect. Sure enough, the bokemeter came back with almost exactly 40 mB, which seems really accurate to me.</p><div></div>

<p>So, you can imagine I'm excited to have this rare and powerful tool, and I'll never go lens shopping again without it. But if anyone's got some documentation, that would be great. And if you have any info on who "M. Johnston" is, be sure to thank him for passing this treasure along.</p>

<p>Wow. I've never heard of this device. It actually measures the smoothness of OOF areas? Interesting. I wonder how it does that?</p>

<p>In connection with photography, "M. Johnston" makes me think of Mike Johnston of The Online Photographer, but surely if he had something like this he wouldn't just be giving it away in a box of junk.</p>

<p>Very cool. Was this just a Nikon tool? I wonder what the strip with yellow or gold in the middle is for. Decoration?</p>

<p>...and the 70-200...?</p>

<p>How about some photos of the internal components, and a closeup through the lens mount?</p>

<p>How is the meter used?<br /> ... What is the light source? How far away?<br /> ... What is the focus setting?<br /> ... What is the f/stop setting?</p>

<p>- Leigh</p>

<p>Think about today's date, folks!</p>

<p>Tom M</p>

<p>PS - Matt, *good one* +1</p>

<p>+4/1</p>

<blockquote>

<p>It actually measures the smoothness of OOF areas? Interesting. I wonder how it does that?</p>

</blockquote>

<p>bokemosis, obviously.</p>

<p>The only reason I knew something was wrong was because the name is misspelled. It's <em>"Bokeometer"</em> (ie, rhymes with thermometer, anemometer, enthalometer, etc.) not <em>"Bokemeter"</em>. Oh, and BTW, the newer digital ones have automatic range-changing.</p>

<p>Tom M</p>

<p>Tom, I'm sure Nikon would not have mis-spelled this. I think it's more like "altimeter." I understand that it's pronounced "boh-KEH-meh-ter."<br /><br />Leigh: I would show some images of the internal workings, but they are ... <em>very</em> difficult to see.</p>

<blockquote>

<p>Leigh: I would show some images of the internal workings, but they are ... <em>very</em> difficult to see.</p>

</blockquote>

<p>Hi Matt,</p>

<p>I can appreciate that, given how incredibly microscopically small they must be. :p<br /> Dare I say infinitesimally small?<br /> Angels on the head of a pin could easily carry the entire circuit, yes?</p>

<p>I'm sure this challenges and even surpasses the current state of the art in miniaturization.<br /> And to think, it was built by hand 50 years ago. Amazing.</p>

<p>Even more amazing... I think that was before the term "bokeh" was invented.</p>

<p>- Leigh</p>

<p>Ah. Cute. Okay. April Fool's Day strikes again. I remember thinking that this seemed like a very unlikely gadget (not only is bokeh quality somewhat subjective, but it's really only within the last ten or twenty years that people have been so obsessed with it), but the mock-up was impressively well-done. Nice work, Matt.</p>

<p>Leigh / Craig, the German optical industry used the term, <em>Ebenbilddruckmesser</em>, ie, "exact image compression indicator" for their version of this device years before the Japanese coined the term, <em>bokehometer</em>. Unfortunately, everyone could pronounce "okey - bokey", but no one could pronounce the German word, so the Japanese word stuck.</p>

<p>As a historical note, the scales on all Leica and Zeiss Ebenbilddruckmesse only ran from -5 to +5 EBBDM units. It didn't need to go further.</p>

<p>Tom M</p>

<p>There wasn't a functioning Leica "Glow-O-meter" in that box as well, was there Matt ?</p>

<p> </p>

<blockquote>

<p>Leigh, the German optical industry used the term, <em>Ebenbilddruckmesser</em>, ie, "exact image compression indicator" years before the Japanese coined the term, <em>bokeh</em>.</p>

</blockquote>

<p>Hi Tom,</p>

<p>I'm certainly not an expert on the ancient German photo industry, but...</p>

<p>The word Druckmeßer is commonly used for physical gauges, like anamometers, barometers, etc.,<br>

as opposed to electrical meters.</p>

<p>Perhaps usage has changed over the years.</p>

<p>- Leigh</p>

 

<p>Hi Leigh - Good point. There has been a lot of discussion in the literature about the possible principles of operation of an <em>Ebenbilddruckmesse</em>r. Because of the name, and because it appeared so early in the century, it was probably based on physical rather than electrical measurements, but since no one has actually found one, we don't know for sure.</p>

<p>Tom M</p>

<p>Hi Tom,</p>

<p>Yes, we're frequently confronted with uncertainty and speculation regarding ancient technology<br /> when no examples exist in the archaeological record.</p>

<p>Consider the Antikythera Mechanism. Quite interesting. Too bad it's impossible. :p</p>

<p>- Leigh</p>

<p>This is just a cheap Japanese knockoff of the original German gonculator.</p>

<p>No, the gonculator was a totally different design.</p>

<p>This is a rather ingenious device, obviously designed to circumvent the German gonculator patent.</p>

<p>- Leigh</p>

 

<p>The gold strip in the middle is probably the bokeh calibration slot. You take a picture that has perfect bokeh, slide it into the slot and calibrate the meter accordingly.</p>

<p>Close.</p>

<p>I think it's actually a calibration target. You have to aim the lens at it to calibrate the meter.</p>

<p>Of course this is a major physical challenge, as are suggestions for certain personal actions. :o</p>

<p>- Leigh</p>

 

<p>Matt, did you find a long stand and a bunch of skyhooks in that box as well? And does that Bokemeter run on air-cells? I also notice it's the deluxe version with 6 screws holding the lensmount.</p>

<p>Best instrument I ever came across in a junk shop was a thing a bit similar to yours called a "Deminrolit tester" - seriously, I didn't make that name up! I never did find out exactly what it was supposed to do, but it had a nice big old meter on the front of it. Seem to remember that it was a Pentax/Praktica 42mm screw thread fitting though with a pneumatic bulb release and took 19 PP7.5 batteries.</p>