#903 Strange behavior of focuslock with Canon G9
Hi,
There is a strange problem using the focuslock function with a Canon Powershot G9 camera. The commands below demonstrate it.
We have a fixed camera and an object which we can place in front of the camera or remove it, making the camera focus on our object or on the scene.
# Object close to the camera
user@host $ gphoto2 --port usb:001,122 --capture-image-and-download
# Result from exiftags: Subject Distance: 0.400 m
# Object removed
user@host $ gphoto2 --port usb:001,122 --capture-image-and-download
# Result from exiftags: Subject Distance: 1.097 m
# Everything is all right so far, now we lock the focus
user@host $ gphoto2 --port usb:001,122 --set-config=focuslock=on
# Object close to the camera
user@host $ gphoto2 --port usb:001,122 --capture-image-and-download
# And here it starts behaving strange. We would expect the value for Subject Distance to be 1.097, however the result from exiftags is 0.400 m. This means that the camera has focused on the object instead of using the locked focus.
# Then we remove the object again
user@host $ gphoto2 --port usb:001,122 --capture-image-and-download
# And the result from exiftags is again 0.400 m, which means that the focus has locked on the last value.
However, sometimes when we lock the focus for the first time we get what we want, i.e. the value of the focus from the previous capture. But if we unlock the focus after that and try to lock it again we get what is shown above. On a rare occasion we can get two adequate consecutive lock-unlock results, after which the camera will exhibit the same strange behaviour again.
Sorry for the lengthy explanation, I hope it more or less demonstrates the problem.
Thank you in advance.
I have no immediate idea, this will need some debugging :/ lets hope I can reproduce with the SX100IS