1 D MK 4's cross type sensor suitable for ...?

[stephan_matthies]

<p>Hello everybody,<br>

Before I spend a lot of money: According to Canon the cross-type-sensors of the 1 D MK4 only work fully (horiz. + vert.) with two f4-lenses (17-40 and 24-104) and some f2.8-lenses (up to 400 f2.8) with or without the 1.4 extender. There is no mention of the 500 f4. Simply put: Do I not have the advantage of 1 D MK4's fantastic AF system and its cross-type sensors with the 500 f4? In other words, leaving the mm-reach aside, is the combo 1 D MK4 + 400 f2.8 focussing faster than the 1 D MK4 + 500 f4? Does anyone have any experience with this? Thanks in advance<br>

Stephan<br>

---------<br>

Here is the quote from the Canon website:<br>

The remaining 38 cross-type AF points are vertical line sensitive at f/2.8 <br />and horizontal line sensitive at f/5.6. If the lens in use has a maximum <br />aperture of f/2.8 or faster, high precision focusing with cross-type sensors <br />will be possible. If the lens’ maximum aperture if f/5.6 or faster, AF will <br />still function with horizontal line detection.<br>

In an upgrade from previous EOS cameras, the following lenses and <br />lens/extender combinations will also function with cross-type AF at all 39 <br />cross-type AF points, even though the maximum aperture is f/4:</p>

<ul>

<li> EF17-40mm f/4L USM </li>

<li>EF24-105mm f/4L IS USM </li>

<li>EF70-200mm f/2.8L IS USM + Extender EF1.4x II </li>

<li>EF200mm f/2L IS USM + Extender EF2x II </li>

<li>EF300mm f/2.8L IS USM + Extender EF1.4xII </li>

<li>EF400mm f/2.8L IS USM + Extender EF1.4x II </li>

</ul>

<p>-----------</p>

 

[craig_meddaugh]

<p>The 400/2.8 will always focus faster than the 500/4 due to its larger max aperture. For a lot of applications, the cross-type sensors are a bit of hype as they only give you an advantage when the your subject consists of strongly patterned lines that are parallel to the orientation of the single dimension sensor. Not that typical of a scenario with these sorts of lenses. </p>

<p>That being said, the 500/4 with the 1dIV focuses plenty fast as very accurate. </p>

[stephan_matthies]

<p>Thanks Craig,<br>

although that does not make it easier to decide on the bucks to be spent.</p>

[eric merrill]

<p>Stephan:</p>

<p>The 500/4 focuses blazingly fast on a 1D4, as does a 300/2.8. I can't speak to the speed of the 400/2.8.</p>

<p>I wouldn't hesitate to buy a 1D4 and pair it with a 500/4.</p>

<p>Eric</p>

[dcstep]

<p>Also, you need to consider the 500mm f/4 Series II with the 1.4x TC III. My understanding is that the AF will be enhanced, particularly with the TC. Also to be considered is the 1-lb weight savings and improved IS that gives two extra stops.</p>

<p>If you do buy a 500mm, I can guarantee that you'll want to use it with a 1.4xTC. ;-)</p>