IXUS 160 Focal Plane
Posted: 02 Apr 2018, 17:37
Hi there,
I have a bit of an issue with my two IXUS 160.
I'm using some undocumented deep firmware commands in CHDK to directly position the focussing motor.
That way i can reliably and very precisely set the focus.
While trying to find out the best settings i noticed that the focal plane does not appear to be parallel to the imaging plane.
I aligned to camera perpendicular to the platen by aiming it directly at the reflection of the lens in the platen.
An image of a gridded paper seems to agree that the alignment is spot on.
See the two attached images. Notice how in one image the top is sharp and the buttom is blurry and vice versa?
If the focal plane was parallel to the imaging plane i imagine thered be one setting where everything was in focus with evenly decreasing sharpness towards the edges.
In any case - did anyone here experience this as well, and found a solution? Are my cameras defective?
What works reasonably well for me is taking 3 consecutive images with different focal points and then using a focus stacking software to create an evenly sharp image.
Unfortunately that slows everything down by orders of magnitudes, having to wait for 3 images to be taken, and then processing them in a focus stacker.
I have a bit of an issue with my two IXUS 160.
I'm using some undocumented deep firmware commands in CHDK to directly position the focussing motor.
That way i can reliably and very precisely set the focus.
While trying to find out the best settings i noticed that the focal plane does not appear to be parallel to the imaging plane.
I aligned to camera perpendicular to the platen by aiming it directly at the reflection of the lens in the platen.
An image of a gridded paper seems to agree that the alignment is spot on.
See the two attached images. Notice how in one image the top is sharp and the buttom is blurry and vice versa?
If the focal plane was parallel to the imaging plane i imagine thered be one setting where everything was in focus with evenly decreasing sharpness towards the edges.
In any case - did anyone here experience this as well, and found a solution? Are my cameras defective?
What works reasonably well for me is taking 3 consecutive images with different focal points and then using a focus stacking software to create an evenly sharp image.
Unfortunately that slows everything down by orders of magnitudes, having to wait for 3 images to be taken, and then processing them in a focus stacker.