I'm an unhappy owner of brand new Canon 80D. I still have 350D which served me for nearly a decade. I use the same 24-105 1:4 L IS lens with both of them.
It turned out that lens is blurry. I've tested with other lenses and body is fine.
After the purchase of 80D I went for a trip and made many pictures. They looked fine on LCD screen, but on a PC, even when viewed as fit to screen (not 1to1), those pictures all look blurry.
So I've done micro-adjustments for 80D and 24-105 lens with Focal 2 software, a tripod and long enough exposure time. It computed adjustment of -3 which doesn't seem much. As far as I understand Focal changes the adjustment and analyzes picture of printed focusing board to calculate its sharpness. From the charts it looks that it really found the sharpest setting.
I have to note that I've made "Auto-focus consistency" tests for both phase auto-focus and contrast based with Live View. Both give more or less the same result in sharpness and sharpness of consecutive takes are the same.
I've also checked whether I could manually focus better, but each move on the focusing collar results in less focused view in the viewfinder.
For me it seems that auto-focus does work properly so why pictures downloaded look so bad?
I've also tried different Picture styles, sharpening settings etc. in Digital Photo Professional after taking a RAW.
I've visually checked the sensor for dirt also and lost all hopes to figure out what's happening.
Here's a comparison of photos taken with the exact same lens, on exactly the same setup. The same crop is cut out and megapixels matched.
Pictures and reports from Focal can be found under my gdrive
What else can I check? Should I send it to Canon service under guarantee? How to convince them not to send it back with information "it works for us"?