[snostorm]

I don't really understand why people have this problem. When I focus, I look through the viewfinder to ensure the target is in focus. The AF is just a substitute for me adjusting the focus manually, It does the work of turning the dial, but I am responsible to ensure it focussed on my intended subject. Don't people check where the focus is when they use AF?

As a Pentax DSLR shooter since the DS, I was forced to learn the fine points of using the SAFOX variants early on and since doing this, have had little trouble with AF accuracy. I'd like to have smaller and more numerous points, and think it would help a lot of shooters have more confidence in the system, but the 11 point system is very usable if the photographer does his part as audiobomber suggests. . . and my vision leaves something to be desired. . .

This is not to say that I wouldn't want more focus points (which implies smaller ones to retain the overall coverage). This would make the system more easily used by more people and cut down the complaints from those who don't understand how to use it to the best effect.

Perhaps Pentax could develop a way to optionally limit the center point focus sensor coverage to allow a more precise AF point. . .

Scott

[audiobomber]

not in my experience but then I regularly see people posting about the poor focusing of Pentax in low light, not some thing I have ever had a issue with and at the end of the day

I never had much trouble in low light with a K100DS, K-x or K20D. I had a K-5 that was hopeless in tungsten light.

[audiobomber]

I'd like to have smaller and more numerous points, and think it would help a lot of shooters have more confidence in the system, but the 11 point system is very usable if the photographer does his part as audiobomber suggests. . . and my vision leaves something to be desired.

I only use the center point or MF.

This is not to say that I wouldn't want more focus points (which implies smaller ones to retain the overall coverage). This would make the system more easily used by more people and cut down the complaints from those who don't understand how to use it to the best effect.

Some people let the camera choose the focal point (auto select). These people are asking for trouble. I would never give up control of AF to the camera. (Bird in flight excepted)

[Spodeworld]

If the focus points are too large for accuracy, is there an approach to take to help mitigate the problem to improve accuracy?

[snostorm]

If the focus points are too large for accuracy, is there an approach to take to help mitigate the problem to improve accuracy?

Hi Spodeworld,

I suggest taking some time to experiment to map the actual area and location of the focus points that you use in relation to the etchings on your focusing screen first. Make sure that the diopter is adjusted correctly for your vision, then when you shoot, concentrate on the subject in the viewfinder with the same intensity that you would if you were focusing manually, confirm focus visually, then take the shot. I also try to be very aware of everything else in the focus sensor area and try make something on my subject the dominant contrast border in the focus sensor area. Once I'm satisfied that my subject is in focus, I lock focus, recompose as necessary, and take the shot.

The central focus sensor area is the largest and probably the most sensitive. It's roughly the size and location of the central ( ) markings on your viewfinder, but location can vary slightly from camera to camera. The actual sensor is cross shaped with lines bisecting the circle vertically and horizontally like the traditional picture of the crosshairs in a rifle scope. It senses contrast borders that intersect the lines of the sensor. The AF system tries to find the point where contrast borders intersect the sensor lines and make them as narrow as possible (maximizing contrast on the sensor). The system cannot guess your intended focus point, the photographer must make sure that you give it something to work with.

Scott