I have been a long term Canon user and have had various Canon DSLR since around 2006-7. I have just bought a new 90D and took it out today for my first photo shoot. Some of the images have come out fine but most look like this! What am I doing wrong?
This is not user error, seems like the sensor is malfunctioning. If its new take it back and show them and swap for a different model. I would use the stores return policy if you exhibit such a malfunctions right away after purchase. The reason i say this....Canon would take it for service and my experience is they could have it for weeks and you need to pay shipping to send it to them. And you would get a yours back after they serviced whatever they needed. Personally I would start with one that works perfect out of the gate, and let that go back to canon for refurbish from the store instead.
It's an ex demo and the shop I bought it from has given me the details of their repair agent in Glasgow who seems to have a very good reputation so let's wait and see. I sent it back in Monday.
They tested the camera fully, reset everything and recalibrated. They asked for the SD card that I was using. It was one I bought off Wish(!!). It turned out that the card was a fake and was part of the problem although there were errors that had to be reset on the camera. I need to get a new SD card to add to my 32GB 120mb SanDisk. Waiting for it to come back so I can try out my new Macro extension tubes.
a word of warning on macro tubes, when i first started out i bought a set of EF macro tubes from neewer and they couldnt take the weight of the heavier ef lenses and broke apart, i was lucky and it happened when the camera and lens was on the table down loading, at the time i had no idea that tubes would or could fail in that way. i only trust canon tubes and extenders with my EF mounts. its more of a heads up message just in case.
Thankfully the issue was just into your SD Card. I would say check the compatible SD Cards which can work well and that have a higher transfer speed of data to be written while clicking photos and videos. Wish you luck on your photography.