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View Full Version : 50D aperture fault - Anyone have a similar problem?

swag72
15-03-2009, 14:02
In the last three outings with my 50D I have had the following problem twice. I am using the setting where I have shutter speed on the front turnwheel, aperture on the large wheel at the back and focussing on the joystick.

All is going well, and then the aperture will not change. I change to AV from M, no luck. I can not alter the aperture at all. Shutter speed still changeable, and all the other settings, just not the aperture.

So twice now I have resorted to resetting the camera settings and taking out the battery. Of course then I have to go back and reset in the menu, but at least it is working again.

So, anyone any experience of this? I am running on the latest v3 firmware. Does this sound bad? Do I need to go back to the retailer?
33L
15-03-2009, 15:12
I have never had any problem like that with the 50D, Is it the same lens that was on when it happened both times.

I really cant think of anything lese that might be causing it.
mrgubby
15-03-2009, 15:14
I had it happen on my 30D, it turned out to be a dirty contact on my grip .
IanC_UK
15-03-2009, 15:15
check the contacts on the lens and camera body, and also grip if you have one, its possible the lens is losing communication with the camera and thats whats stopping it working.
Canon Bob
15-03-2009, 15:28
Sara....is this with the 100-400?

Bob
swag72
15-03-2009, 15:32
The lens has been different both times. It's done it with my 100mm macro and my 17-55mm - Not with the 100-400 yet, but haven't used that for a little while.

I've got no grip, so can not blame it on that. As it's a different lens, I guess it's not the contacts?
IanC_UK
15-03-2009, 15:38
The lens has been different both times. It's done it with my 100mm macro and my 17-55mm - Not with the 100-400 yet, but haven't used that for a little while.

I've got no grip, so can not blame it on that. As it's a different lens, I guess it's not the contacts?

Could still be the contacts on the camera body ;)

I use a tiny drop of eclipse on a pecpad and just lightly wipe over them, wait for the eclipse to evapoprate and then refit the lens and try again see if it still does it.
swag72
15-03-2009, 15:50
I use a tiny drop of eclipse on a pecpad and just lightly wipe over them, wait for the eclipse to evapoprate and then refit the lens and try again see if it still does it.

Don't have any at the moment - Anything I could use as a stop gap?
Canon Bob
15-03-2009, 15:53
Don't have any at the moment - Anything I could use as a stop gap?

A dab of vodka or gin would work.

Bob
swag72
15-03-2009, 16:02
A dab of vodka or gin would work.

Bob

I must be the only house in UK with neither!! How about something from the garage? Methylated spirit? or White Spirit?
dlh
15-03-2009, 16:06
I know this is probably a silly idea (and I don't know if it works the same as on my 20d) but have you got the power switch moved all the way round to the line rather than just to on?
RichardtheSane
15-03-2009, 16:16
I know this is probably a silly idea (and I don't know if it works the same as on my 20d) but have you got the power switch moved all the way round to the line rather than just to on?
Echoed my first thought when describing the symptoms...
swag72
15-03-2009, 16:21
I know this is probably a silly idea (and I don't know if it works the same as on my 20d) but have you got the power switch moved all the way round to the line rather than just to on?

I really don't know to be honest - But I will make sure I keep the power switch on all the way round to the line. Why would this 'on' setting cause this?
BigDex
15-03-2009, 16:28
Because with the power switch in the mid-position, the large thumbwheel on the back is disabled... it is only active with the power switch all the way up.

Worth checking!
Canon Bob
15-03-2009, 16:28
I must be the only house in UK with neither!! How about something from the garage? Methylated spirit? or White Spirit?

You're in good company Sara...there's none in this house either.

I'd avoid white spirit or meths as they both have either oil or colourant added.

Personally, I don't believe it's a comms problem as you'd have probably seen a focussing error at the same time as the body-lens communication uses the same contacts for both functions and no message is sent when you simply adjust the aperture...that happens at the moment of shooting.

Bob
swag72
15-03-2009, 16:30
Sounds like perhaps I didn't have the on switch in the right position then :bang::bang: Better get those settings all sorted again then!!

Thanks for your help everyone - Hopefully it has now been sorted :thumbs:
tarmac_chaser
15-03-2009, 21:57
Always try to check the power switch is in the right position first if this happens, usually the culprit!