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Is Panasonic 12-35mm II parfocal?

Started Feb 25, 2018 | Discussions thread
hindesite Veteran Member • Posts: 4,893
Re: Real parfocal is important in video though

Stejo wrote:

hindesite wrote:

Why?

Doesn't the example show the possibility (which is my assumption) that the lens manages it own corrections of focus to maintain parfocality; after all, these lens know their own characteristics and could adjust accordingly (just as they used to do using mechanical designs in the past).

Nothing to do with the camera body for this function; AF is not involved.

The lens can't power its AF motor by itself. Nor does it have an advanced processing engine on board typically. In order to keep shifting the elements around to maintain parfocality, somebody has to apply precise amounts of electrical current at specific moments. It seems unlikely that a lens would be allowed access to power on demand without the body provisioning for it.

Furthermore, the more likely scenario is that the amount of current required has to be judged on the basis of the projected image rather than focal length change. Seems reasonable to assume that as you're zooming in and out the body adjusts focus accordingly to maintain maximum contrast at the original focus plane.

Not so. You are talking as if the camera is refocusing using AF. It isn't.

If I put my 100-400 on the Z Cam E1, it behaves just the same.

And the E1 is dumb as a brick. No DFD (or any other) trickery there.

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