[Shuttershane]

Maybe I have something setup wrong. But when I turn the switch at the top (on/off/dof preview) this actually takes a pictures instead of showing me the DOF preview through the view finder. Is this how it is suppose to work?

[AOShep]

I had the same thing happen to me with my K10D. It wasn't always that way, but as it turned out I had made some changes in the menus not knowing what it actually did. Forgot which option it was but once I found it the DOF switch worked again. I'll try to retrace my steps and post if someone doesn't beat me to it.

[AOShep]

OK, found it. See if this is the same on your 645D. In the menu options "Preview Method" has 2 choices, Optical Preview and Digital Preview. The Digital Preview appears to take a picture but it is only holding it in memory to display exposure, composition and focus info on the LCD panel before shooting.

[Shuttershane]

I think that's it. I thought turning that off meant no preview after an image was taken thanks!

[Royce Howland]

Yes, that's the setting you needed to change. Using the digital DOF preview can be helpful because you can zoom in and pan around the scene to check for critical focus. It's faster to do this using this preview function than to actually take a photo and then check focus during image play back.

Focusing by eye with optical DOF preview, it may or may not be a bit challenging to get complete critical sharpness. When I find that's the case, I switch over to digital DOF preview to tighten up the focus. It's the best we can get on the 645D without having a live view mode...