Anti alias filter removal on Canon 5d?

[chris_ogilvie]

<p>I am interested in having the anti alias (AA or "optical low pass") filter removed from my Canon 5d. This service is offered by <<a href="http://www.maxmax.com/hot_rod_visible.htm">maxmax.com/hot_rod_visible.htm</a>> as an example. I am less interested in arguments or opinions on why and why not, and much more interested in actual user experiences.<br>

If you had this conversion performed, could you share your experiences, both positive and negative? Not just regarding sharpness and moire, but also color fidelity and ISO shift (if any) etc? Did any other issues raise their heads as a result of this conversion? What about workmanship and subsequent reliability of your 5d?<br>

Appreciate your input!<br>

Chris Ogilvie</p>

[shambrick007]

<p>Looking forward to seeing some results, as a normal 5D w/a good lens yields some of the sharpest RAWs that I've ever gotten out of a camera. I have not had the chance to extensively play w/my 5D II yet to compare.</p>

[joseph_wisniewski]

<p>As I recall, the Canon 5D is one of the few cameras where a successful AA filter removal is not possible. An AA filter is really two filters, a slab of LiNbO3 that spreads the imave vertically, and another that spreads it horizontally. The 5D reduces the filter stack height by using the vertical LiNbO3 filter as the cover glass for the sensor.</p>

<p>So, an AA filter removal will simply result in strange looking "vertical only" aliasing. Even if you use an aliasing removal plugin, like "demoirize" from P1C1, you can't really fix 5D weirdness.</p>

[peter_foiles2]

<p>I just checked Canon's white paper on the 5D. The low pass filter is indeed two layers, one vertical and one horizontal. However if I understand Canon's explanation correctly both layers along with IR and polarizing filters are implemented as a single "independent crystal plate" which also serves as the cover glass. So when the the cover glass is removed both low pass filter layers are removed. </p>

[joseph_wisniewski]

<p>Never take a Canon white paper too seriously. People who have actually tried removing the 5D AA filter run into the problem of one of the two LiNbO3 plates (and phase retarder) being used as the LCD cover glass.<br>

http://www.digitalcamerainfo.com/content/canon-makes-it-official-announces-full-frame-eos-5d-.htm<br>

http://www.luminous-landscape.com/forum/lofiversion/index.php/t34051.html</p>

[joseph_wisniewski]

<p>OK, that's weird. One of my links magically got changed to "(link)", while the other (and longer of the two) is still in its original form.</p>

<p>Are some sites on a "leave along" list?</p>

[chris_ogilvie]

<p>I want to thank everyone for their responses! It seems that while the option to removing the anti alias filter is fairly well known, this is not a popular procedure. Few appear to have done this, especially on a Canon 5d. Even on maxmax.com there are few photo examples for the 5d compared to many for various Nikons. Makes sence if indeed they can only remove 1/2 of the AA filter! The best user info is on the linked Luminous Landscape discussion.</p>