Lenses on K10D do not focus correctly on low f stops eg; f1.4/2.0 but focus well on higher f stops eg f11. On the lower f stops the lenses are back focusing by around 4 to 5 cm. Any help Thanks
Although you think the lens is in focus, when stopped down, I know it is not.
There are enough articles that tell about Depth Of Field, but I give a short explanation.
The DOF from a 50 mm lens on a APS-C camera, when set to f /1,4. when you focus on 1 meter, is just 2 cm when on f /4 you have a totoal of 6 cm and on f /11 it is 11cm. So wen your camera / lens combination has a back focus of about 5 cm, it will come within the 11 cm you get in f /11. Still the picture is not in focus, but you see what you want to see sharp.
I searched through the complete manual, scanned the review on Dpreview and searched the site from Richo, but noting to find about correcting back or front focus. on the K10D. Perhaps, because in the days this camera came on the market, they thought the photographer who uses f /1.4 lenses is used with manual focus.
I'm, not sure, but perhaps someone on the Richo / Pentax service centre can tell you, if they can correct the setting for your lens.
To my experience, the front or back focus is in the camera. (the six or 7 lenses I use on my camera, all have the same back focus, but my Nikon has a setting to correct that.
So if you want to use your lens without any change made to your camera, there is only one option, focus manually.
Sorry I could not find more.
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