Newish T5i Phase Detection Problem-Anything Left To Try?

[KI2K]

My T5i is about 6 months old, also have good T3 body to help in my troubleshooting. T5i will no longer lock focus on like flying airplanes or birds in any lighting and with fresh battery- it just hunts, stays busy, or focuses as blur in all modes and with multiple lenses that all work fine on T3 body. Still subjects are no issue, crisp focus.

It feels like the t5i body has some new and suddenly onset issue, but I'd love to hear any other ideas to try based on the symptom before I engage Canon for repair.

If it does need to go back, does this sound like a calibration issue? I'm assuming warranty would cover it, but curious why it would just develop this sort of issue. Also curious about typical turnaround time if it does have to go back.

Thanks for any input and advice.

[ebiggs1]

Did you set it to AI-Servo by mistake?  If, yes, set it back to One Shot AF.  Or, do a Clear all settings and a Clear all Custom setting reset in the Menu.

[KI2K]

Thanks for reply,. I did verify One Shot selected, also cleared all settings, and fairly meticulously compared both settings and lenses between my old T3 and my new T5i before turning here for help. I've taken thousands of pictures since buying the T5i and feel sure that I'm seeing a bona fide problem as this camera and the lenses in use faithfully very recently locked on to what they struggle with now (only planes and birds in flight, and now clouds even with great contrast) and it may be getting worse as I can't even seem to take cloud pictures on the T5i. Again, move same lenses to T3 body and performance is as expected again.

I do see another thing that concerns me: I can't acquire dust data, either on the T5i anymore.

-Lee

[KI2K]

Ah ha- bigger issues are afoot here, though it's not making complete sense. I noticed the foam gasket for focusing screen was pinched and looking not right (I've never touched this part of the camera, and generally have no interest out of respect for its importance). Looking closer, hold down clip for screen not evenly seated on both sides, like one side was raised a bit from screen. I tried to seat it with gentle push on clip tab, and it popped off. Then screen and shim followed, so whole thing going to Canon. This was a new purchase from Amazon, I hope it wasn't actually a return or whatever sold as new. I've had Canon film cameras and the T3 prior to to T5i, and I can't imagine that this left the factory like that.

[ebiggs1]

Canon service is where this camera belongs.  If it can not be returned to the store where you bought it.

[KI2K]

Agreed, I have repair ticket started, and off she'll go in the next day or two. Thanks for the input.

[ebiggs1]

+1  

[TCampbell]

The focusing screen is on the top of the mirror chamber. The phase detection AF sensors are actually on the bottom of the chamber. The mirror is semi transparent. When it is down, some light can pass through to a second (smaller) folding mirror which bounces the light down to the AF points.

If you put the camera into manual cleaning mode you would see a few tiny holes in the bottom of the chamber. The AF points are located there. Make sure they are not obstructed.

You may want to test each individual AF point to learn if just one point is affected or if they are all the same.

[KI2K]

Thanks, Tim. As I mentioned, the focusing screen popped out when I touched the hold-down bracket that I noticed was cocked. My theory is that, given this T5i has only been in service since April, perhaps it was odd out of the box and getting worse with use over time until it became noticeable. I don't know if that's even plausible, but I can't imagine why the hold-down would ever become dislodged. I spent years (decades actually) with an AE1-Program then my T3 before the T5i, and I shoot a LOT of pictures. I could tell that something really odd changed rather suddenly, and after using my T3 to rule out lenses, and then running through reset of settings, etc. I opted just to send it off to Canon. Shipped it out today, with focusing screen, shim, and bracket in bag. Odd stuff.