35L has serious back focus issues, but is fine when I shoot photos in live view.

Hey guys, I recently bought a 35L, 135L, and a 7D from POTN and after a month of shooting I realized the 35L has an enormous back focus problem. I tried using Micro Adjustment and even -20 is not enough to fix the issue on the 35L. I've shot with the 135L and all the shots come out very clear, as I shot with both of these lenses two years ago before selling them off.

I tried shooting pictures with using 7D's live view and all the pictures come out fine when I am using the 35L. It does not have any back focus issues but when I look through the viewfinder and shoot the back focus issue comes back.

Should I send the 7D, or the 35L, or both the 35L and 7D, to a photo repair store (Nippon Photo Clinic in NYC) and have them assess the situation?

Live view autofocuses at the sensor plane, so unless you have a serious problem with the sensor or lens, you should always get accurate focus in live view.

If you can't MA the lens to calibrate out the error, it's time to send it in for repair / calibration, sadly. If you only use the lens with that camera, send them in as a set. If you use the lens with other cameras, it's worth sending it in separately for calibration.