Canon 7D focus issue-new observation

Started Mar 31, 2013 | Discussions thread
TTMartin Veteran Member • Posts: 7,304
Re: If it happens in MF, it is not a focus issue.

rndman wrote:

Mr Ed M wrote:

rndman wrote:

plugin wrote:

I have no idea what is causing it (mine does not do anything like that), but if you are talking to Canon techs and call it a focus issue, you are making it harder for them to diagnose.

My suspicion  is that there could be some issue with the sensor cleaning mechanism. That is the only thing that can move the sensor. I know it ma not be moving back and forth, but that should be enough to create the un-sharp pictures..

It doesn't move the sensor, it moves the filter in front of the sensor.

Camera shake with a big long lens can be caused by a number of factors from the wind, to surface vibrations, to simply touching the camera.

Nothing new here that I haven't seen with reasonable explanation to the cause.

I agree.

But if the tripod is setup inside the house with subject being focused is outside, and you are just watching the image on the LCD from a distance. Now there should be no wind effect or touch effect. May be only floor vibration to some extent. Also the vibration just shakes the image it does not become wavy. What is the explanation to that..

If the vibration of the tripod is front to back it will be wavy, if it is side to side it will be shake, or a combination of the above.

As for a shooting through a window from indoor to outdoor, you multiply the issues, floor movement, shake from the house and wind movement in the pane of glass.

I had my Induro AT-413 (rated for 44 lbs) set up with my 7D and Sigma 150-500 outdoors, live view 10X zoom, focused on an eagles nest. When the wind blew you could see it in the image.

I had the same tripod set up indoors with my 7D and Sigma 120-300 with a 2X TC, doing MFA adjustment. Using the EOS utility live view method (zoom+200%). When I got up from the computer and walked over to the camera, you could see the movement on the computer screen, and it would take a few moments after I sat down for it to stabilize.

For the poster complaining about issues with Spot AF and AIServo. Canon recommends using Spot AF and AIServo together.

I agree there is nothing new being described here.

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