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View Full Version : Autofocus in Av or Tv mode?




furious
Apr 3, 2010, 01:57 AM
Hi, I recently purchased a secondhand Canon 40d.

Is the camera meant to autofocus in Av or Tv mode. The camera is not. I have only experience with P&S cameras. SLRs and their features are new to me. I am thinking it could be one of the custom function setting has been set by the previous owner to be this way.

:Edit: I am using the 40d paired with a Canon 50mm f1.4.



AlaskaMoose
Apr 3, 2010, 02:05 AM
Hi, I recently purchased a secondhand Canon 40d.

Is the camera meant to autofocus in Av or Tv mode. The camera is not. I have only experience with P&S cameras. SLRs and their features are new to me. I am thinking it could be one of the custom function setting has been set by the previous owner to be this way.

:Edit: I am using the 40d paired with a Canon 50mm f1.4.

The camera autofocuses in all modes, including the fully automatic ones, and M.

Av is aperture priority (you control the lens aperture by rotating the wheel by your index finger near the shutter button), and the camera selects the best matching shutter speed possible (depending on ISO speed).

Tv is shutter priority. You control the shutter speed, and the camera selects the best matching lens aperture possible (depending on ISO speed).

Make sure that the AF/M switch on the lens barrel is set to AF (autofocus), first. How do you know that the camera is not focusing automatically?

I would suggest for you to buy David D. Bush book written for the 40D. It will save you a lot of time learning about this camera.
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Several of us in this forum can also help you go through the steps setting up you camera, but you have to let us know what you are doing (settings, etc.).

furious
Apr 3, 2010, 02:09 AM
I turn it on and point it at the wall and all I get is a blurry picture in Av or Tv modes;););)

:edit: I have not changed any setting. Only used it the way it was sent to me.

AlaskaMoose
Apr 3, 2010, 02:12 AM
I turn it on and point it at the wall and all I get is a blurry picture in Av or Tv modes;););)
Point it at something else and see if it focuses. Make sure the AF/M switch on the side of the lens is switched to AF. Press the shutter button half-way and let the camera focus, and then press it all the way. How close to the wall are you?

Forgot something else: there is a very small wheel on the right side of the eyepiece. Point the camera at a white wall, and then turn the wheel one way (or the other way) to adjust the camera's eyepiece to your eye.

furious
Apr 3, 2010, 02:31 AM
I just reset the custom function and now it is working. :o Silly me.

Thank you for your help. :D

AlaskaMoose
Apr 3, 2010, 01:02 PM
I just reset the custom function and now it is working. :o Silly me.

Thank you for your help. :D

Well, that's good news. The seller must have had the camera set to focus with another button (other than the shutter button)?.

furious
Apr 3, 2010, 06:34 PM
Well, that's good news. The seller must have had the camera set to focus with another button (other than the shutter button)?.

He may have. He has a studio and I get the feeling this camera was bit long in the tooth for him. Perfect for me though. As I would never been able to afford this camera had it not been so cheap. :D