Options. 11-19-2022 06:21 PM. I recently purchased a 70-200mm F2.8L USM lens and when I hold the shutter button half way, the lens is just focusing back and forth, and not finding anything to focus on. If it does focus on an image,80% of the time the image is out of focus. I’ve tried it on a T5 and an 80D but the problem still exists. EF 17-40mm f/4 L USM Autofocus Issue. 05-29-2020 03:01 PM. I hope that any of you can provide some direction. I was going to use this lens with my 5D Mark II this morning and noticed that the autofocus wasn't working. Checked and double checked my settings and didn't find anything wrong with them. Canon EOS R7 review. The Canon EOS R7 is a 32.5MP APS-C mirrorless camera built around Canon's RF mount. It sits as a more expensive sister model to the EOS R10, launched alongside it. It's targeted at a similar enthusiast photographer market as the existing EOS 90D DSLR and, perhaps, the EOS M6 II. Difficult subjects for AF (Auto Focus) AF (Auto Focus) can fail to achieve focus (the focus confirmation light blinks) on certain subjects such as the following: Low-contrast subjects. (ex. blue sky, solid-color walls, etc.) Subjects in low light. Extremely backlit reflective subjects. (ex. car with a reflective body) Overlapping near and far Canon EOS 5D Mark II Canon EOS 7D Canon EF 400mm f/5.6L USM Canon EF-S 15-85mm f/3.5-5.6 IS USM Canon EF 100mm F2.8L Macro IS USM +5 more Reply Reply with quote Reply to thread Complain The Canon EOS II driver detects the camera model automatically, and adjusts its internal settings to account for differences between models. (For the Canon EOS I driver you must choose the model manually.) Please note that Canon releases new models frequently, and that a software update is always required to support a new model. Finally, once you have Magic Lantern installed on your camera, press the delete button to access the ML menu. Go over to the overlay tab, find the "Focus Peak" option and press the set button on 04-13-2021 04:02 PM. I have been having some issues with this lens (70-200 2.8 IS ii). These examples were shot at f/ 2.8 and when you zoom in, you can see that really there is nothing in focus. It appears like a total lack of focal plane. I use back button auto focus + single point and focus on the eyes. For video I suggest the 5d III. The 5dIII has better options for video with Magic Lantern (higher resolution options and framerate options). Don't expect much from autofocus. On the 6d, you can half press the shutter button while in liveview (and not recording) and then it autofocus on where the focus box is, or if facedetection is on, it Make a back up of your settings to an SD Card. Now perform a reset. Both main and custom settings. Retest AF function. These types of issues are often caused by an incorrect setting, unless you are using 3rd party glass or adapter. XOnM.