01-30-2019 02:05 PM - edited 01-30-2019 02:43 PM
" both lenses had the same issue. now out of warranty the same problem persists and has gotton worse."
Since both lenses show the same results then I would first assume technique or camera problem. If you are confident on your technique then it would be camera.
If you think its back focus you can check that by placing the camera on your tripod and using live view to focus on a subject.
In LiveView the focusing is based on exactly what the sensor sees. "Normal" AF does not.
I would start with having Canon check the camera only.
01-30-2019 05:11 PM
OK I am back. I had a quick job to get out of the way.
I looked at your samples. Now don't take any offense with this but your test are really meaningless. You have different everything. Different resolutions, different apertures, different SS and even different color balance. That makes it very difficult to analyse what is going on. Here are your same test shots more or less balanced in color. Although I still see some difference it may be do to aperture and SS differences. Or it could be PS changing the resolution to match Who knows by now?
When you do a critical test you need to keep everything equal as much as possible. Same light, same aperture and same SS. Same ISO, etc.....everything. Try this again and this time for instance use ISO 200, SS of 1/500 at f8 same distance and tilt of the target on all three (or whatever the lighting conditions require). I would like the FL to all be the same too but I guess that's not possible.
01-30-2019 06:05 PM
Here's something else to look at. Even though the 60D isn't user adjustable you can at least determine if you have a problem.
01-30-2019 06:21 PM
OK if you are satisfied with how you compared them, it looks like you have a bad copy of the lens. Its not the camera most likely. The kit 70-300mm zoom is not one of Canon's best efforts anyway. Sorry, I tried.