Rob Trek Forum

I was out shooting trains yesterday I had the oddest problem with my 40 to 150 today. I was in a position to shoot the steam train. All of a sudden the camera went into manual focus. Tried a number to things and no go. It would go back into autofocus then I would change the exposure and would go back into manual focus. I saw the camera was not recognizing the lens in the display. I slapped on the 12 to 45 and no issues. Checked it out when I got home..same issue. Lens was not recognized but there was no error. So I put on the MC 20 and no issues. Autofocus was back on track. I hit the contacts of the lens with an electronic cleaner. BOOM working great... At least for now. Real-world problems. I never thought cleaning the contacts would have worked.

I really thought my lens needed to go in repair. I spoke to one of my ex-coworkers and he said he had the same trouble with the 100 to 400 and solved the lens recognition issue the same way.

I hope this information is helpful

Is it possible that the focus ring was bumped into the manual mode? I had this happen with my 17mm f18 lens, panic ensued until I discovered the focus ring had slipped into the manual position.

Lemonhawk wrote: ↑

15 Nov 2020 22:24

Is it possible that the focus ring was bumped into the manual mode? I had this happen with my 17mm f18 lens, panic ensued until I discovered the focus ring had slipped into the manual position.

Thank you for the reply. I have been bit by that before *LOL* . I was shooting a hot air balloon and I was in the chase vehicle. When I tried to focus on the balloon, NOTHING!!!. It too me about a minute before I figured it out the clutch moved.

This was different. Cleaning the contacts solved the problem.

Good to know you solved it! In my case I was looking thru the EVF and completely missed the MF indication!