Hi, I am facing an issue which I will like to seek help and advice from all the experts on the forum. Often, my welfies (i.e me holding the camera,
so the camera will be at most about 60cm, (2') from you.
and everyone else sitting standing a short distance (<10 metres) behind me) turns out to have bokeh effect,
They are beyond the field of acceptable sharpness. I suggest you read about "Depth of Field" (DOF). You want the depth of that field to cover from the front of your face to the back of that group of people. The closer the front of that field is to the camera, the more difficult it is to stretch it far away.
The minimum aperture for the lens on a G7XII is f/11. with the lens zoomed out to cover a wide angle, it will have a focal length of 8.8m. If you focus at 60cm with a focal length of 8.8mm on a 1" sensor, you will get a DOF of about 8.7 m, with about 8.4 m meters of the field beyond where it focussed. So you cannot get the 10m DOF you say you want with this camera if you hand hold it.
Furthermore, at 8.8mm focal length and an aperture of f/11, the aperture diameter is 8.8mm/11 = 0.8mm. Such a small aperture diameter produces a lot of diffraction blur. Any images you take at this setting will be blurry. Also, if you have stopped down to f/11, you camera will need to use either a slow shutter speed or a high ISO to get adequate image lightness. If you are not in direct sunlight and try to keep the ISO at base, the shutter is likely to be so slow as to cause motion blur from camera movement as you hold it at arm's length. If you keep the shutter fast enough to prevent camera motion blur, the exposure is likely to be so low as to cause considerable noisiness.
which is undesirable for me. Because except for myself, everyone else in the photo turns out blurry. I turns to switch to use Aperture priority mode when taking welfies. However the whole photos turn out to be blurry. I will like to get some guidance what is there any recommended setting (ISO, shutter speed, aperture) to get rid of the unwanted bokeh effect? I understand that it will be different under bright light, indoor/outdoor night. Will appreciate if there can be some guidance for me to test and try for future photo-taking.
Background:
Camera: Canon G7X Mark II
How photo is taken: Taken most of the time in Full Auto mode, LED tilted forwards and human take up 1/2 to 3/4 of the bottom of photo in landscape mode.
The most important changes to make would be to the distance relationships between the camera and the humans. If you can use a selfie stick to get the camera 1m from the closest subject, and close up the group so that the farthest person is no more than about 3.8 m behind the closest person, then you can set the aperture to f/5.6. This will let in four times as much light as f/11, allowing you to use a somewhat faster shutter speed and avoid motion blur.You will need to have the selfie stick firmly braced however, or you will get even more motion blur.
An option that produces a much better result is resting the camera on a tripod or other firm holder at an even farther shooting distance. If you shoot from a distance of 2m, you can use an aperture of f/2.8, which lets in four times as much light at f/5.6, and can cover up to 4m behind the front person. Shooting from this distance will also eliminate any distortion that comes from having the camera too close to the subject.
If you must shoot "welfies" holding the camera, then use a smartphone. Its smaller sensor actually helps overcome the DOF problems you are experiencing. However, it won't help with the distortion of close subjects.
