This is a frequent and common comment -
First my disclosure - I am on Pentax Forums because I use Pentax dSLR and I like them -
they seem to work fine for me - of course YMMV -
Having said that, I hope my experience with Pentax AF is worth sharing here
I have used the K-x quite extensively (about shot count 59,000) and regularly in very dark environments -
where there are parts that are literally below both the metering and AF limits of the K-x -
I am not saying the K-x never hunts - but mostly I can focus even in those very dark conditions -
and AF under poor light is supposed to be a Pentax weak point.
I am not saying for a moment that my copy of the K-x is some super-boosted AF focusing monster -
it is "bog-standard" and I have not done any modifications to it, not only that I have only the two most humble kit zooms (18-55 and 50-200)
Please see Post
#132 and
#131 in thread
Kx in Use (
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It is quite common to have difficulties when trying to focus on the face/eyes in the dark.
So I look for something else close by that may be easier to focus on - it may not be as critically correct - but mostly the depth of field takes care of any differences.
take this example -
the main subject's face was basically in the shadows - and it was not possible to focus on the face/glasses.
However the bell of the trombone had bright highlights which contrasted with the rest in darkness - gave a much easier target to focus on.
Perhaps seeing the original unprocessed (other than re-sizing) might help to visualize the scene a bit better?
EXIF attached
How dark was this?
ISO5000, f/3.5, 1/5sec, -0.7 comp; 18mm
metering segment read outs:
according to the metering segment it is about
-1.3LV at the face
this is about -1.3 stops below the spec'd metering,
and -0.3 stops below the spec'd AF limit of the K-x -
metering is supposed to be 0LV and AF -1LV, but using a f/1.4 lens -
I am using f/3.5 which is -2 2/3 stop slower/dimmer..
This one -
certainly could not focus on any face -
and even if the K-x had a focus-assist light it probably would not have helped at this distance -
focused on a candle flame...
So one can see the K-x is more than capable of focusing in very low light, without any focusing aid.