Well, Pentax finally emailed a response regarding my poor AF, took them over a week.
Not what I was hoping for but at least it's a response. Here is what he wrote.
Dear Customer,
Thank you for contacting Pentax regarding your K-5.
Autofocusing in low light is often a test for any camera. Using a fast shutter speed to freeze the subject means that the camera either must use a larger lens aperture and/or raise the sensitivity to counterbalance the reduced amount of light striking the image sensor. Also, the lower the light, the harder it is for the camera to confirm focus. On the other hand, using a slower shutter speed to compensate for low-light levels often means a moving subject will be blurred, so while the camera may confirm focus correctly, it's entirely possible that camera shake or a low shutter speed is causing the poor performance.
Another factor which adds to the difficulty of shooting in low-light is the fact that as the lens is zoomed out (to bring the subject closer) the maximum (widest) available lens aperture becomes smaller, thus further reducing the light needed to record a good image. If flash cannot be used, the best advice is to raise the ISO as needed and if a DSLR is being used, to consider using a lens with a larger maximum aperture (i.e. our DA* 50-135mm f2.8) and using the lens at less than maximum zoom extension. The wider the angle, the easier it is to stabilize the lens and due to increased amount of light.
It is also important to ensure that you are using the AF assist light in low light scenarios. On a further note, if the light is too low it may be necessary to use a tripod. If you have followed all of the precautions above and are still concerned that the camera is not performing as it should, I recommend that you send us test photos for review. Please send original jpeg or raw files to
info@pentax.com that exhibit the problem.
The latest firmware version for the K-5 is v1.01.
If you are in need of further assistance, please respond to this email or call our technical support center at 800-877-0155 begin_of_the_skype_highlighting**************800-877-0155******end_of_the_skype_highlighting.