I have been researching the Pentax SMC DA\* 300mm f/4 ED [IF] SDM as a possible wildlife lens to use with my K-5.
There are only a limited number of reviews of the lens from reputable sources and even fewer with MTF data.

I have been checking the result of this lens in combination with the apsc K-5 at photozone, however my understanding of MTF data is limited. What also important is that I can compare this data to the Canon and Nikon 300/F4 equivalents, but it is simply to complex to get my head around it.

[Photozone MTF for the Pentax](http://www.photozone.de/pentax/643-pentax300f4?start=1)

Your help in comparing and understanding the data is much appreciated.