Thank you very much for your reply.
Sorry for not giving the details and samples.
I've been struggling with uploading photos as it exceed the size limit. Therefore, I have uploaded some cropped images.
The two jpeg DSC00897 and DSC00898 are cropped from the same photo with ISO100, 25mm, f/8, 1/250s, with tripod.
DSC1302 and DSC1300 are cropped from another photo with ISO200, 16mm, f/8, 1/200s, without tripod.
Both were taken with A7III. It seems to me that the images are not as sharp as samples I can see from others, but I do not know what the problem is.
Sorry that the original image is not provided as I cannot upload it without exceeding the max total size.
Thank you very much for reply again, and sorry for not providing clear details as this is my first time posing here and I am not familiar with using the forum.