Can't set f-stop on 20D

Has anyone else had this problem? I haven't used my 20D for a few days, and I tried to take a pic this evening of my new puppy to use for a Christmas card. Set the camera on Manual, set shutter speed, and aperature just stays at 4.0. I put on a different lens - the 85 1.8, and aperature reads 00. (I started with the 17-40 2.8) I put on the nifty 50 it reads 4.0 again. And of course the camera is just out of the warranty period.

Jackie Boyd

I'm guessing you know the main dial in the back is used to change the aperture value in 'M' mode?

And make sure the "on" switch is set to the topmost setting. If you don't put it there, the command dial is disabled in M.

liza wrote in post #2382208
And make sure the "on" switch is set to the topmost setting. If you don't put it there, the command dial is disabled in M.

This is what I was going to suggest.

I do that ALL the time.

yup, I know about the suggestions above, and checked all of that initially, before posting here. Still doesn't work.

Have you checked the contacts on the lens mount, to make sure there is not debris that prevents proper connection? The 00 is an indication of no lens (such as using my Olmpus lens on EF mount adapter).

checked the contacts. All look clean. BTW, if I put the camera in aperature mode I *can* change the aperature.

Remove the battery, replace it, and turn the camera on again to the second ON setting. Then try once again. It may need to be rebooted.

Thanks Liza - did that. It didn't change anything. I then tried my last resort and "reset all camera functions." That worked. I don't know what I possibly could have set that would have not allowed me to set the aperature. I think I will still call Canon support tomorrow.

Thanks everyone for your help!

Jackie

Isn't there a custom function that makes it so the back wheel selects AF points rather than aperture?

I know there is one to use the wheel to select focus point, but I am not aware if that also makes it not set aperature. I did have it set to use the wheel to select focus point. Back to the manual!

jboyd wrote in post #2382384
checked the contacts. All look clean. BTW, if I put the camera in aperature mode I *can* change the aperature.

You are not putting the power switch into the THIRD setting (the line above the word 'On')!

If you put the power switch to On, even in Manual mode only the wheel near the shutter button works. On only way for the big wheel on the back to work (to control the aperture) is when the Power button points to the Line!

Wilt wrote in post #2382930
You are not putting the power switch into the THIRD setting (the line above the word 'On')!

If you put the power switch to On, even in Manual mode only the wheel near the shutter button works. On only way for the big wheel on the back to work (to control the aperture) is when the Power button points to the Line!

I did have the setting to the line above "on" and it still didn't work. That was one of the first things I checked.

this looks like a simple case of broken/dirty lens, OR, if all lenses do that, a simple case of i was too lazy to turn off the camera while changing lenses. if it's just the 85 that does it (which you can check with your second body, the 10d), then it's the lens that needs fixing, else, most likely some small firmware glitch that can probably be fixed simply by re-installing the firmware