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 @ 28mm Center Crop</h1> 
<TR>
<TD>Tamron 28-75 f/2.8 @ 28mm
<TD>Canon 17-40mm f/4L @ 28mm</TD>
</TR>





<TR>
<TD><img src =  "http://etischer.com/1dmk2/lenstests/28mm/full.jpg">
<br>full image </TD>

<TD></TD>
</TR>






<TR>
<TD><img src = "http://www.etischer.com/1dmk2/lenstests/28mm/cen/HP8F0529.JPG">
<br>Tamron f/2.8</TD>

<TD></TD>
</TR>





<TR>
<TD><img src = "http://www.etischer.com/1dmk2/lenstests/28mm/cen/HP8F0530.JPG">
<br>Tamron f/4</TD>

<TD><img src = "http://www.etischer.com/1dmk2/lenstests/28mm/cen/HP8F0536.JPG">
<br>Canon f/4</TD>
</TR>








<TR>
<TD><img src = "http://www.etischer.com/1dmk2/lenstests/28mm/cen/HP8F0531.JPG">
<br>Tamron f/5.6</TD>

<TD><img src = "http://www.etischer.com/1dmk2/lenstests/28mm/cen/HP8F0537.JPG">
<br>Canon f/5.6</TD>
</TR>





<TR>
<TD><img src = "http://www.etischer.com/1dmk2/lenstests/28mm/cen/HP8F0532.JPG">
<br>Tamron f/8</TD>

<TD><img src = "http://www.etischer.com/1dmk2/lenstests/28mm/cen/HP8F0538.JPG">
<br>Canon f/8</TD>
</TR>



<TR>
<TD><img src = "http://www.etischer.com/1dmk2/lenstests/28mm/cen/HP8F0533.JPG">
<br>Tamron f/11</TD>

<TD><img src = "http://www.etischer.com/1dmk2/lenstests/28mm/cen/HP8F0539.JPG">
<br>Canon f/11</TD>
</TR>




<TR>
<TD><img src = "http://www.etischer.com/1dmk2/lenstests/28mm/cen/HP8F0534.JPG">
<br>Tamron f/16</TD>

<TD><img src = "http://www.etischer.com/1dmk2/lenstests/28mm/cen/HP8F0540.JPG">
<br>Canon f/16</TD>
</TR>






<TR>
<TD><img src = "http://www.etischer.com/1dmk2/lenstests/28mm/cen/HP8F0535.JPG">
<br>Tamron f/22</TD>

<TD><img src = "http://www.etischer.com/1dmk2/lenstests/28mm/cen/HP8F0541.JPG">
<br>Canon f/22</TD>
</TR>


</table><br><br><hr>








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

<h1>Lens test @ 28mm Edge Crop</h1> 
<TR>
<TD>Tamron 28-75 f/2.8 @ 28mm
<TD>Canon 17-40mm f/4L @ 28mm</TD>
</TR>





<TR>
<TD><img src =  "http://etischer.com/1dmk2/lenstests/28mm/full.jpg">
<br>full image </TD>

<TD></TD>
</TR>






<TR>
<TD><img src = "http://www.etischer.com/1dmk2/lenstests/28mm/edge/HP8F0529.JPG">
<br>Tamron f/2.8</TD>

<TD></TD>
</TR>





<TR>
<TD><img src = "http://www.etischer.com/1dmk2/lenstests/28mm/edge/HP8F0530.JPG">
<br>Tamron f/4</TD>

<TD><img src = "http://www.etischer.com/1dmk2/lenstests/28mm/edge/HP8F0536.JPG">
<br>Canon f/4</TD>
</TR>








<TR>
<TD><img src = "http://www.etischer.com/1dmk2/lenstests/28mm/edge/HP8F0531.JPG">
<br>Tamron f/5.6</TD>

<TD><img src = "http://www.etischer.com/1dmk2/lenstests/28mm/edge/HP8F0537.JPG">
<br>Canon f/5.6</TD>
</TR>





<TR>
<TD><img src = "http://www.etischer.com/1dmk2/lenstests/28mm/edge/HP8F0532.JPG">
<br>Tamron f/8</TD>

<TD><img src = "http://www.etischer.com/1dmk2/lenstests/28mm/edge/HP8F0538.JPG">
<br>Canon f/8</TD>
</TR>



<TR>
<TD><img src = "http://www.etischer.com/1dmk2/lenstests/28mm/edge/HP8F0533.JPG">
<br>Tamron f/11</TD>

<TD><img src = "http://www.etischer.com/1dmk2/lenstests/28mm/edge/HP8F0539.JPG">
<br>Canon f/11</TD>
</TR>




<TR>
<TD><img src = "http://www.etischer.com/1dmk2/lenstests/28mm/edge/HP8F0534.JPG">
<br>Tamron f/16</TD>

<TD><img src = "http://www.etischer.com/1dmk2/lenstests/28mm/edge/HP8F0540.JPG">
<br>Canon f/16</TD>
</TR>






<TR>
<TD><img src = "http://www.etischer.com/1dmk2/lenstests/28mm/edge/HP8F0535.JPG">
<br>Tamron f/22</TD>

<TD><img src = "http://www.etischer.com/1dmk2/lenstests/28mm/edge/HP8F0541.JPG">
<br>Canon f/22</TD>
</TR>


</table><br><br><hr>