Here are some comparison shots using a 1Dmk2 with 1.3x crop factor.  <hr><br><Br>

<TABLE WIDTH="90%"  CELLSPACING="1" CELLPADDING="4" BORDER="1">

<h1>Lens test @ 17mm Center Crop</h1> 
<TR>
<TD>Simga 12-24mm f/4.5 - 5.6 @ 17mm
<TD>Canon 17-40mm f/4L @ 17mm</TD>
</TR>



<TR>
<TD><img src =  "http://etischer.com/1dmk2/lenstests/17mm/full.jpg">
<br>full image </TD>
<TD><img src = "http://etischer.com/1dmk2/lenstests/17mm/cen/HP8F0500.JPG">
<br>Canon f/4</TD>
</TR>

<TR>
<TD><img src =  "http://etischer.com/1dmk2/lenstests/17mm/cen/HP8F0493.JPG">
<br>Sigma f/5 </TD>
<TD><img src = "http://etischer.com/1dmk2/lenstests/17mm/cen/HP8F0501.JPG">
<br>Canon f/5.6</TD>
</TR>



<TR>
<TD><img src =  "http://etischer.com/1dmk2/lenstests/17mm/cen/HP8F0494.JPG">
<br> Sigma f/7 </TD>
<TD><img src = "http://etischer.com/1dmk2/lenstests/17mm/cen/HP8F0502.JPG">
<br>Canon f/8</TD>
</TR>


<TR>
<TD><img src =  "http://etischer.com/1dmk2/lenstests/17mm/cen/HP8F0495.JPG">
<br> Sigma f/10 </TD>
<TD><img src = "http://etischer.com/1dmk2/lenstests/17mm/cen/HP8F0503.JPG">
<br>Canon f/11</TD>
</TR>

<TR>
<TD><img src =  "http://etischer.com/1dmk2/lenstests/17mm/cen/HP8F0496.JPG">
<br> Sigma f/14 </TD>
<TD><img src = "http://etischer.com/1dmk2/lenstests/17mm/cen/HP8F0504.JPG">
<br>Canon f/16</TD>
</TR>



<TR>
<TD><img src =  "http://etischer.com/1dmk2/lenstests/17mm/cen/HP8F0497.JPG">
<br>Sigma f/25 </TD>
<TD><img src = "http://etischer.com/1dmk2/lenstests/17mm/cen/HP8F0505.JPG">
<br>Canon f/22</TD>
</TR>
</table><br><br><hr>



<TABLE WIDTH="90%"  CELLSPACING="1" CELLPADDING="4" BORDER="1">

<h1>Lens test @ 17mm Edge Crop</h1> 
<TR>
<TD>Simga 12-24mm f/4.5 - 5.6 @ 17mm
<TD>Canon 17-40mm f/4L @ 17mm</TD>
</TR>



<TR>
<TD><img src =  "http://etischer.com/1dmk2/lenstests/17mm/full.jpg">
<br>full image </TD>
<TD><img src = "http://etischer.com/1dmk2/lenstests/17mm/edge/HP8F0500.JPG">
<br>Canon f/4</TD>
</TR>

<TR>
<TD><img src =  "http://etischer.com/1dmk2/lenstests/17mm/edge/HP8F0493.JPG">
<br>Sigma f/5 </TD>
<TD><img src = "http://etischer.com/1dmk2/lenstests/17mm/edge/HP8F0501.JPG">
<br>Canon f/5.6</TD>
</TR>



<TR>
<TD><img src =  "http://etischer.com/1dmk2/lenstests/17mm/edge/HP8F0494.JPG">
<br> Sigma f/7 </TD>
<TD><img src = "http://etischer.com/1dmk2/lenstests/17mm/edge/HP8F0502.JPG">
<br>Canon f/8</TD>
</TR>


<TR>
<TD><img src =  "http://etischer.com/1dmk2/lenstests/17mm/edge/HP8F0495.JPG">
<br> Sigma f/10 </TD>
<TD><img src = "http://etischer.com/1dmk2/lenstests/17mm/edge/HP8F0503.JPG">
<br>Canon f/11</TD>
</TR>

<TR>
<TD><img src =  "http://etischer.com/1dmk2/lenstests/17mm/edge/HP8F0496.JPG">
<br> Sigma f/14 </TD>
<TD><img src = "http://etischer.com/1dmk2/lenstests/17mm/edge/HP8F0504.JPG">
<br>Canon f/16</TD>
</TR>



<TR>
<TD><img src =  "http://etischer.com/1dmk2/lenstests/17mm/edge/HP8F0497.JPG">
<br>Sigma f/25 </TD>
<TD><img src = "http://etischer.com/1dmk2/lenstests/17mm/edge/HP8F0505.JPG">
<br>Canon f/22</TD>
</TR>
</table><br><br>