[stevebrot]

but is it supposed to reflect the DOF

It will reflect the DOF for the aperture opening as you view. This is not always the maximum for the lens mounted and in bright light might be a little narrower. That being said, when not magnified, focus peaking can be pretty "blunt" and not suitable for fine focus. The highlighted zone depends on angle to the sensor and contrast.


Steve

[johnmflores]

I've just tried it. Seems to work nicely enough, but is it supposed to reflect the DOF ? I ask, because I changed the aperture and used the DOF preview button, but I could not see much difference in the Peaking area being displayed.

No, the aperture is adjusted to ensure that the Live View image is well exposed, so if you point it towards a bright light source and then away you will hear the aperture adjust.

Other systems (i.e., Panasonic) work differently, allowing you to control the aperture in Live View, which their mirrorless cameras are always in. I prefer this because you can see at a glance whether your settings will over- or under-expose a shot or areas of a shot. This is one feature that I wish Pentax would implement.

Don't expect to get tack sharp images at wide open apertures of moving subjects this way. The Focus Peaking will get you close though, and if you stop down a bit and focus bracket you increase your odds of getting the shot.

[Na Horuk]

I've just tried it. Seems to work nicely enough, but is it supposed to reflect the DOF ?

If you have a lens with A-setting on aperture ring or a DA, DFA lens, the camera will behave in a certain way in live view. It will automatically stop down the lens a little bit during live view (to help with composition and protect against sudden bright light surges, which could theoretically damage the sensor with very bright aperture lenses). When you press the digital zoom button, it will open the aperture to max size.This is why peaking is best used together with digital zoom (its the Info or Ok button on the camera, I think. Depends on model). You can check this behaviour by going outside in daylight and hitting LV, then look into the lens. Set Av mode to f8, then look at the aperture when no command is given, when DoF preview is pressed, when digital zoom is pressed. Also, peaking is meant to mostly represent the focus centre - it does not represent the DoF accurately, even if lens is at same aperture during live view as it is when taking the photo.

If you are using a manual lens with aperture lever (like M series lenses), then the camera will keep the lens wide open until you take a photo. If you have M mode selected, the camera will stop down the aperture to what is chosen on aperture ring. All other settings (like auto ISO) and modes will default to Av mode, which has constant metering but never stops down the lens, no matter what you chose on aperture ring.
Dead lenses (like m42 adapted lenses, or certain K-mount lenses with no aperture lever) will simply show you whatever you manually set, since the camera cannot know or affect the aperture on the lens.

[stevebrot]

This is why peaking is best used together with digital zoom (its the Info or Ok button on the camera, I think. Depends on model)

I think this is more appropriately called magnified live view. Digital zoom is another beast. Remember that the OP is shooting an animal in motion with the sole advantage that it is a confined space (zoo?). Live view is a suboptimal solution at best.


Steve