[2351HD]

Hello,
I am mainly asking this question of K3 users just to get an idea of what I may expect live view performance to be like on the new 645Z when I get it.

When you are using live view, does it keep the aperture open full time, then stop down to take the image? or does it close the aperture when you adjust it on the camera, showing the real-time adjustment?

If its the former, is there a way to close the aperture to the shooting aperture to view DOF in the live view frame, while moving around the screen to check focus through the scene?

The main reason I ask is that I use it that way on my Sony Nex6 and manual lenses, set the aperture on the lens and shutter speed on camera as required and the live view image gets brighter/dimmer as you change it.

Thanks, Scott

[Paul the Sunman]

Whether you are using the viewfinder or LiveView, the lens aperture is fully open. In either case, the default action when you use the Depth of Field Preview ring surrounding the shutter button is to stop the lens down to the selected aperture for visual (optical) preview. However, there is an optional (digital preview) set in the menus to take a test image, not saved to your card (unless you wish), which can be viewed and magnified on the preview screen.

So "Optical Preview" (the default action) works in Live View exactly the same way as with the viewfinder. If you want to magnify portions of the image for closer examination, then "Digital Preview" is the go. On the K3 it's set in the Camera-4 menu.

[stevebrot]

Whether you are using the viewfinder or LiveView, the lens aperture is fully open.

Maybe my settings are off, but I have found that when using DA, FA, and A-series lenses, the lens will stop down to about f/4.5 in live view when the scene is relatively bright and even narrower if very bright.* This can be problematic if doing manual focus. The workarounds that I have found are:

Move the aperture ring (if present) to other than the "A" position and shoot in M mode
-- or --
Press the "OK" button for several seconds to switch to magnified view
-- or --
Set the aperture to maximum and use the optical DOF preview (requires holding switch in position)

All of these force the aperture to wide open. For lenses lacking the "A" contacts, the aperture stays full-open during live view except at time of exposure.


Steve

* Firmware v1.03. It is my understanding that this behavior is designed to protect the sensor circuitry or some-such.

[Paul the Sunman]

Maybe my settings are off, but I have found that when using DA, FA, and A-series lenses, the lens will stop down to about f/4.5 in live view when the scene is relatively bright and even narrower if very bright.

I didn't know that, as I hardly ever use Live View. How can you tell that it is stopping down, just by the DOF? You're a brave man trying to circumvent the behaviour if it's designed to protect the sensor!

However, I doubt that it's relevant to the question posed in the thread. I guess that the Digital Preview image is taken at the selected f number, whether it was less than or greater than f/4.5. Can't test at the moment; not bright enough.

[stevebrot]

How can you tell that it is stopping down, just by the DOF?

I heard the mechanism when I was seeing how the live view worked and then turned the camera around to see that the lens was stopped down rather than open. Before then, I was puzzled that the focus peaking seemed to be very generous. Now we know why.


Steve