1951 USAF resolution test chart

<h2 id="pattern-format">Pattern format</h2>
<p>The common MIL-STD-150A format consists of six groups in a compact spiral arrangement of three layers. The largest two groups, forming the first layer, are located on the outer sides. The smaller layers consist of repeating progressively smaller pairs toward the center. Each group consists of six elements, numbered from 1 to 6. Within the same layer, the odd-numbered groups appear contiguously from 1 through 6 from the upper right corner. The first element of the even-numbered groups is at the lower right of the layer, with the remaining 2 through 6, at the left. The scales and dimensions of the bars are given by the expression
</p>

resolution (lp/mm)
        
        =
        
          2
          
            
              group
            
            +
            (
            
              element
            
            −
            1
            )
            
              /
            
            6
          
        
        ,
      
    
    {\displaystyle {\text{resolution (lp/mm)}}=2^{{\text{group}}+({\text{element}}-1)/6},}

<p>although usually the following lookup table will be more convenient to use. The line pair (lp) means a black and a white line.
</p>
Number of line pairs per millimeter in USAF Resolving Power Test Target 1951<table><tbody><tr><td></td><th colspan="12">Group number</th></tr><tr><th>Element</th><th>−2</th><th>−1</th><th>0</th><th>1</th><th>2</th><th>3</th><th>4</th><th>5</th><th>6</th><th>7</th><th>8</th><th>9</th></tr><tr><th>1</th><td>0.250</td><td>0.500</td><td>1.00</td><td>2.00</td><td>4.00</td><td>8.00</td><td>16.00</td><td>32.0</td><td>64.0</td><td>128.0</td><td>256.0</td><td>512.0</td></tr><tr><th>2</th><td>0.281</td><td>0.561</td><td>1.12</td><td>2.24</td><td>4.49</td><td>8.98</td><td>17.96</td><td>35.9</td><td>71.8</td><td>143.7</td><td>287.4</td><td>574.7</td></tr><tr><th>3</th><td>0.315</td><td>0.630</td><td>1.26</td><td>2.52</td><td>5.04</td><td>10.08</td><td>20.16</td><td>40.3</td><td>80.6</td><td>161.3</td><td>322.5</td><td>645.1</td></tr><tr><th>4</th><td>0.354</td><td>0.707</td><td>1.41</td><td>2.83</td><td>5.66</td><td>11.31</td><td>22.63</td><td>45.3</td><td>90.5</td><td>181.0</td><td>362.0</td><td>724.1</td></tr><tr><th>5</th><td>0.397</td><td>0.794</td><td>1.59</td><td>3.17</td><td>6.35</td><td>12.70</td><td>25.40</td><td>50.8</td><td>101.6</td><td>203.2</td><td>406.4</td><td>812.7</td></tr><tr><th>6</th><td>0.445</td><td>0.891</td><td>1.78</td><td>3.56</td><td>7.13</td><td>14.25</td><td>28.51</td><td>57.0</td><td>114.0</td><td>228.1</td><td>456.1</td><td>912.3</td></tr></tbody></table>

Width of a line in micrometers in USAF Resolving Power Test Target 1951<table><tbody><tr><td></td><th colspan="12">Group number</th></tr><tr><th>Element</th><th>−2</th><th>−1</th><th>0</th><th>1</th><th>2</th><th>3</th><th>4</th><th>5</th><th>6</th><th>7</th><th>8</th><th>9</th></tr><tr><th>1</th><td>2000.00</td><td>1000.00</td><td>500.00</td><td>250.00</td><td>125.00</td><td>62.50</td><td>31.25</td><td>15.63</td><td>7.81</td><td>3.91</td><td>1.95</td><td>0.98</td></tr><tr><th>2</th><td>1781.80</td><td>890.90</td><td>445.45</td><td>222.72</td><td>111.36</td><td>55.68</td><td>27.84</td><td>13.92</td><td>6.96</td><td>3.48</td><td>1.74</td><td>0.87</td></tr><tr><th>3</th><td>1587.40</td><td>793.70</td><td>396.85</td><td>198.43</td><td>99.21</td><td>49.61</td><td>24.80</td><td>12.40</td><td>6.20</td><td>3.10</td><td>1.55</td><td>0.78</td></tr><tr><th>4</th><td>1414.21</td><td>707.11</td><td>353.55</td><td>176.78</td><td>88.39</td><td>44.19</td><td>22.10</td><td>11.05</td><td>5.52</td><td>2.76</td><td>1.38</td><td>0.69</td></tr><tr><th>5</th><td>1259.92</td><td>629.96</td><td>314.98</td><td>157.49</td><td>78.75</td><td>39.37</td><td>19.69</td><td>9.84</td><td>4.92</td><td>2.46</td><td>1.23</td><td>0.62</td></tr><tr><th>6</th><td>1122.46</td><td>561.23</td><td>280.62</td><td>140.31</td><td>70.15</td><td>35.08</td><td>17.54</td><td>8.77</td><td>4.38</td><td>2.19</td><td>1.10</td><td>0.55</td></tr></tbody></table>
<h2 id="images">Images</h2>

<h2 id="see-also">See also</h2>
<ul><li><a href="/facts/Optical_resolution/TcLkPYFw">USAF 1951 target</a> section, in <a href="/facts/Optical_resolution/TcLkPYFw">Optical resolution</a></li></ul>

<h2 id="external-links">External links</h2>
<ul><li><a href="https://web.archive.org/web/20090525144515/http://www.efg2.com/Lab/ImageProcessing/TestTargets/#USAF1951">efg's Tech Note: USAF 1951 and Microcopy Resolution Test Charts.</a></li>
<li><a href="http://www.takinami.com/yoshihiko/photo/lens_test/USAF.pdf">A USAF 1951 resolution chart</a> in PDF format is provided by <a href="http://www.takinami.com/yoshihiko/photo/lens_test/pdml-procedure.html">Yoshihiko Takinami</a>. This chart should be printed such that the side of the square of the 1st element of the group -2 should be 10 mm long.</li>
<li><a href="http://www.silverfast.com/show/resolution-target/en.html">USAF 1951 Resolution Target</a> Further explanations and examples</li>
<li><a href="http://www.normankoren.com/Tutorials/MTF5.html">Koren 2003</a>: Norman Koren's updated resolution chart better suited for computer analysis</li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>"Document Index for MIL-STD-150". Archived from the original on March 27, 2019. Retrieved August 10, 2019.{{cite web}}:  CS1 maint: bot: original URL status unknown (link) <a href="https://web.archive.org/web/20190327102710/https://quicksearch.dla.mil/qsDocDetails.aspx?ident_number=35531" target="_blank">https://web.archive.org/web/20190327102710/https://quicksearch.dla.mil/qsDocDetails.aspx?ident_number=35531</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
</ol>

1951 USAF resolution test chart open-in-new

1951 USAF resolution test chart