MTC Photography Posted February 1, 1999 Share Posted February 1, 1999 <p>How to use eyes as natural rangefinder and make a calling card rangefinderor draw up a rangefinder at the back of a Minox 8X11 Link to comment Share on other sites More sharing options...
MTC Photography Posted February 1, 1999 Author Share Posted February 1, 1999 <HTML> <HEAD> <META Name="Generator" Content="Lotus Word Pro"></META> <TITLE>Body</TITLE> </HEAD> <BODY BGCOLOR="#C0C0C0"> <BR> <CENTER><TABLE BORDER=10 COLS=1 WIDTH="92%" HEIGHT="10%" BGCOLOR="#FFCC33" > <TR> <TD><FONT COLOR="#FF0000"><FONT SIZE=+3><center>How to make a Rangefinder for MINOX</center></FONT></FONT></TD> </TR></table></center> <font size=5 color="blue"> <p> Viewfinder cameras such as Minox GT-E or Minox B are scale focusing cameras, you have to estimate the distance and set the distance scale on these cameras accordingly. <p> There are many ways to determine the object distance, from eyeballing to using a separate range finder.<P> Do you know that you can make a rangefinder for you Minox subminiatures or Minox 35mm for next to nothing ? <p> All rangefinder has two windows, separated by a distance, called the baseline. The longer the baseline, the more accurate the ranger finder. <P> One day, I suddenly realized that a pair of human eyes is a natural rangefinder, its base line is between 6cm to 8cm. Why can't I use my eyes as a rangefinder to determine the focusing distance of viewfinder cameras such as Minox GT-E or Minox B ? <p> I performed an experiment: I held a ruler with right hand at arms length, first closed my right eye, used only my left eye to align one end of the ruler with a line or an edge of an object, then close my left eye, open the right eye, I noticed that the line now aligned at a distance X to the right of the edge. I noticed that the further the object, the greater the displacement. <P>After some simple calculation I found that the image displacement X is given by the following formula :X =E*(D-A)/D; where E is separation of eyes D is object distance, A is arm's length. <p> For example let Eye separation =7 CM, Arm's length=60 CM ; <p>D=1 M X= 2.8 CM <p>D=1.2M X= 3.5 CM <p>D=1.5M X= 4.2 CM <p>D=1.7M X= 4.5 CM <p>D= 2M X= 4.9 CM <p>D=2.5M X= 5.3 CM <p>D= 3M X= 5.6 CM<p>D= 4M X= 6.0 CM <p>D= 5M X= 6.2 CM<p>D=10M X= 6.6 CM <p>D=20M X= 6.8 CM <CENTER><TABLE BORDER COLS=2 WIDTH="30%" HEIGHT="70%" BGCOLOR="#FFCC33" > <TR> <TD>Distance</TD> <TD>Marking</TD> </TR> <TR> <TD>1 M</TD> <TD> 2.8 CM</TD> </TR> <TR> <TD>1.2M</TD> <TD> 3.5 CM</TD> </TR> <TR> <TD>1.5M</TD> <TD> 4.2 CM</TD> </TR> <TR> <TD>1.7M</TD> <TD> 4.5 CM</TD> </TR> <TR> <TD> 2M</TD> <TD> 4.9 CM</TD> </TR> <TR> <TD>2.5M</TD> <TD>5.3 CM</TD> </TR> <TR> <TD>3M</TD> <TD> 5.6 CM</TD> </TR> <TR> <TD>4M</TD> <TD>6.0 CM</TD> </TR> <TR> <TD>5M </TD> <TD> 6.2 CM</TD> </TR> <TR> <TD>10M</TD> <TD>6.6 CM</TD> </TR> <TR> <TD>20M</TD> <TD> 6.8 CM</TD> </TR> </TABLE></CENTER> <p> I drew these lines on the back of a piece of calling card for use with Minxo GTE I also drew the eye-rangefinder marks at the back of my Minox C. <p> A simpler method of drawing this eye-rangefinder marks is the following: mark 1 m 1.2m 1.5m, 2m,2.5m, 3m,4m etc on the floor,with ruler level at arm's length, read off the ruler at points corresponding to the distances. Then mark these on a piece of calling card or at the back of Minox 8x11. ( which <p> When use, I hold the Minox or calling card leveled with my right hand at arm's length, align one end with left eye, use right eye to read the distance. When object fall between two marks, set distance proportionally.For example, if the object lies between 1.7 M and 2M, set distance at 1.8M <p> After some practice, I now can see two images of calling card from two eyes and read off the distance without closing one eye. <p> Try it, it works. <p> <A href="http://www.greenspun.com/bboard/q-and-a-fetch-msg.tcl?msg_id=000r8i"><h3> A Litte Garden </h3></a> </font> </BODY> </HTML> <hr width =80%> <P> <CENTER> <H2> <FONT FACE="Arial Narrow"><FONT SIZE=+2>A Calling Card Range Finder(meter scale )</FONT></FONT></H2></CENTER> <DIV ALIGN=right> </DIV> <CENTER><TABLE BORDER WIDTH="34%" HEIGHT="50" BGCOLOR="#CCCCCC" > <TR VALIGN=CENTER> <TD ALIGN=CENTER VALIGN=CENTER WIDTH="40%" HEIGHT="200"> <DIV ALIGN=right><FONT SIZE=-2>1</FONT></DIV> </TD> <TD WIDTH="10%"> <DIV ALIGN=right><FONT SIZE=-2>1.2</FONT></DIV> </TD> <TD WIDTH="10%" HEIGHT="100"> <DIV ALIGN=right><FONT SIZE=-2>1.5</FONT></DIV> </TD> <TD WIDTH="10%" HEIGHT="250"> <DIV ALIGN=right><FONT SIZE=-2>2</FONT></DIV> </TD> <TD WIDTH="10%"> <DIV ALIGN=right><FONT SIZE=-2>3</FONT></DIV> </TD> <TD WIDTH="8%"> <DIV ALIGN=right><FONT SIZE=-2>5</FONT></DIV> </TD> <TD WIDTH="6%"> <DIV ALIGN=right><FONT SIZE=-2>10</FONT></DIV> </TD> <TD WIDTH="6%"> <DIV ALIGN=right><FONT SIZE=-2>inf</FONT></DIV> </TD> <TD WIDTH="100"> </TD> </TR> </TABLE></CENTER> <BR> Typical calling card rangefinder for eye distance = 70mm and arm length = 60 cm <BR> To use, hold card at arm's length, use left eye to align left side of card with object, then <BR> close the left eye use right eye to measure off the distance ( in meter ) Link to comment Share on other sites More sharing options...
ray_moth Posted February 22, 2001 Share Posted February 22, 2001 Martin, <p> Like all simple solutions, this one is brilliant! Thank you! <p> Regards, <p> Ray Moth Link to comment Share on other sites More sharing options...
robin_barnsley Posted February 19, 2002 Share Posted February 19, 2002 Martin, <p> Last week I had this idea, only to find you'd beaten me to it. I was thinking of calibrating the wrinkles on my finger! Link to comment Share on other sites More sharing options...
MTC Photography Posted November 6, 2003 Author Share Posted November 6, 2003 Minox C with rangefinder in feet<p> Minox B with rangefinder in meter<div></div> Link to comment Share on other sites More sharing options...
tomchuk Posted March 12, 2005 Share Posted March 12, 2005 This is awesome. I've thrown together a page in php that will generate a card with the proper markings, as well as a hyperfocal distance chart. It's at <a href="http://www.tomchuk.com/rf_hfd/index.php">http://www.tomchuk.com/rf_hfd</a>, enjoy! Link to comment Share on other sites More sharing options...
MTC Photography Posted March 13, 2005 Author Share Posted March 13, 2005 Thomas, your automated program is cool ! Link to comment Share on other sites More sharing options...
shadowfox Posted April 5, 2007 Share Posted April 5, 2007 Martin, you are a genius!Thomas, you are a pragmatic genius! Thanks to both! this is 2007 and your solutions still works and appreciated. Link to comment Share on other sites More sharing options...
alan_rockwood Posted June 30, 2007 Share Posted June 30, 2007 Martin, this is amazing. I just tried this idea out and it is very accurate. The hardest thing is holding the card steady. By the way, I think I have an accurate way to measure the spacing between the eyes. Stand in front of the mirror, close your right eye, and line the tick mark of a ruler up with the center of your left pupil. Carefully holding the ruler in the same position, open the right eye and close the left eye. Determine which tick mark on the ruler the pupil lines up with. Do this several times to get a good measurement. I believe this method virtually eliminates any parallax error or related artifacts, giving a very accurate measurement of the spacing between the eyes. Link to comment Share on other sites More sharing options...
lars_giner Posted September 14, 2007 Share Posted September 14, 2007 As I am an optometrist I would like to add a few details on this subject. I tried making this low-tech rangefinder and it seems to work correctly. However, it is urgent to have a certain level of visual acuity on both eyes to be able to read the lines and align them to the distant subject.This will exclude persons with so-called amblyopia, i.e. functionally one-eyed individuals.Furthermore,special attention should be paid when wearing bifocal or multifocal spectacles, as they possibly might distort the image.Such spectacle lenses are usually customized to fit the (converging) pupil distance at near vision, thus creating a slight move of the image,probably creating a major error when reading the measured distance on the RF card. And, finally, the easiest way to obtain a correct measurement of your pupil distance is to visit your local optician, who will use a device made for this sole purpose. Best regards! Lars Giner Link to comment Share on other sites More sharing options...
alan_rockwood Posted November 10, 2008 Share Posted November 10, 2008 Following up, I have made a several of these rangefinders. I find that old electronic hotel key cards are a good substrate for these devices. I just measure and mark them by hand with an indelible marker. I currently have two rangefinder cards, one matched to the markings on the lens of my Rollei 25TE and one matched to the markings on the lens of my Ricoh 35 ZF. Link to comment Share on other sites More sharing options...
alan_rockwood Posted July 6, 2010 Share Posted July 6, 2010 <p>Correction: not 25TE but 35TE, not that anyone will ever find this old thread.</p> Link to comment Share on other sites More sharing options...
karl_jones Posted December 15, 2010 Share Posted December 15, 2010 <p>I found it :)<br> And it is very helpful indeed.</p> Link to comment Share on other sites More sharing options...
murray_kelly Posted December 16, 2010 Share Posted December 16, 2010 <p>So did I and I printed feet on one side and meters on the other and laminated it to credit card size.<br> Thanks</p> Link to comment Share on other sites More sharing options...
8x11 Posted December 20, 2010 Share Posted December 20, 2010 <p>well if your eyesight is as poor as mine, (forgot watching 3D), you will be in trouble. Me, I still guess....</p> Link to comment Share on other sites More sharing options...
lambert_s. Posted April 18, 2014 Share Posted April 18, 2014 <p>Well, it's over 15 years later and I found this! Very, very clever Martin, and very cool little program, Thomas! Thanks to both!</p> Link to comment Share on other sites More sharing options...
MTC Photography Posted April 19, 2014 Author Share Posted April 19, 2014 <p>Lambert, thanks for your kind words.<br> 15 years ago, when I held my Minox C with a rangefinder sticker at arms length to measure distance, I felt a bit uneasy, at that time most people still used film cameras, and no body held film camera that way, people sometimes looked at me, wandering what this guy is doing ?<br> 15 years later, most people use digital camera, then holding a Minox with rangefinder scale sticker at arms length is just like photographing with a digital camera or a cell phone, no one<br> look at me any more. :)</p> Link to comment Share on other sites More sharing options...
pankaj_dubey1 Posted September 14, 2014 Share Posted September 14, 2014 <p>Has anyone tried a pocket folding hair comb for this.<br /> http://www.mensdirect.com/product/Kent-Mens-Folding-Pocket-Comb-82T/tools-hair-brushes-combs<br /> or<br /> a Quilling comb like this which is 3.9 inches wide.<br> http://www.amazon.com/Quilled-Creations-309-Quilling-Comb/dp/B001689MVI/ref=sr_1_1?ie=UTF8&qid=1410688433&sr=8-1&keywords=paper+quilling+combs<br> <br /> The pupillary distance could be marked on the comb by looking in the mirror and then measuring the distance.<br /> Once that is done, then the distance markings(as calculated by the program) be put on the bristles and the bristles between two marks removed.<br /> The handheld comb would be convenient to hold and fold when not in use.<br /> If instead of arms length, one enters the length at which the comb is held with the arm straight and comfortable then one can comfortably and effectively use this.<br /> ..and unlike me, if you have any hair left worth combing- the infinity end of the scale can be used for that as well :)</p> <p>I will try and jig this over next week or so.</p> <p>Pankaj</p> Link to comment Share on other sites More sharing options...
alan_rockwood Posted September 17, 2014 Share Posted September 17, 2014 <p>Nice to see that this thread is still alive.</p> Link to comment Share on other sites More sharing options...
pankaj_dubey1 Posted September 17, 2014 Share Posted September 17, 2014 <p>..and growing :)<br> Interesting article about using your hands to assess focal length of the lens to be used.<br> http://www.dslrsolutions.net/3298/using-your-hands-as-focal-length-calculator/</p> <p>Two hands wide at an arms length is 50mm lens (full frame).</p> <p>HTH</p> <p>Pankaj</p> Link to comment Share on other sites More sharing options...
ashoketewari Posted March 16, 2016 Share Posted March 16, 2016 <p>fantastic work by both <a href="/photodb/user?user_id=1152913">Thomas Achtemichuk</a> and <a href="/photodb/user?user_id=504260">Martin Tai</a> !!</p> <p>I printed the card on A4 at 100% but <strong>decided to use my smartphone </strong>instead of pasting it on a calling card.<br> <br> --> Took a photo of the printed card on my cell phone (landscape orientation)<br />--> opened the image on my phone, magnified it to match the actual card dimensions (scale on the card)<br />--> took a screenshot (on my phone). <br> Have to turn off the auto-rotate screen orientation option when using the image/card.<br> <br> I was already using a Lightmeter app on my phone ... and now this! </p> Link to comment Share on other sites More sharing options...
MTC Photography Posted March 18, 2016 Author Share Posted March 18, 2016 <p>Ashoke, combine old tech with new tech, great work !</p> Link to comment Share on other sites More sharing options...
MTC Photography Posted November 4, 2020 Author Share Posted November 4, 2020 The human eyes have a baseline about 80mm Leica M6 rangefinder baseline =40mm CONTAX T rangefinder baseline =15mm Hence human eye rangefinder is twice as accurate as Leica M6, and more than 5 times as accurate as Contax T Link to comment Share on other sites More sharing options...
SCL Posted November 4, 2020 Share Posted November 4, 2020 Years ago I found this and keep a copy in my bag just in case: 1 Link to comment Share on other sites More sharing options...
ph. Posted November 24, 2020 Share Posted November 24, 2020 Using the Walther Zapp method, one might instead extend the original measuring chain. Admittedly, having 10 yards of metal chain with bumps every yard might cancel the advantages of carrying a very small camera, but one should be grateful that it is not extended to infinity. The purveyors could always use the standard excuse of high tech inconvenient innovation.... "It is designed to improve user experience". p. Link to comment Share on other sites More sharing options...
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