Author Topic: Parallel action  (Read 1205 times)

garry23

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Parallel action
« on: February 21, 2017, 09:37:21 PM »
I'm thinking about how to implement ICM (intentional camera movement) using, of course, ML Lua.

The idea is simple.

During an open shutter action, move the lens, i.e. coincident with the image being taken.

The ICM technique implies a longish exposure, eg using an ND filter.

Does anyone know if this parallel action is possible?

If it is not, could one of the gurus consider implementing  ;)

Cheers

Garry

dmilligan

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Re: Parallel action
« Reply #1 on: February 21, 2017, 09:50:32 PM »
What do you mean by "move the lens"? The only physical movement on a lens that we can control from software is the focus position. For lenses with IS, it might be possible to jiggle the IS element, but AFAIK, we don't know how to do that (requires reverse engineering, probably on the MPU).

garry23

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Re: Parallel action
« Reply #2 on: February 21, 2017, 11:20:00 PM »
@dmilligan

The idea is to 'zoom' away from the FP in a controlled way.  I appreciate that at the moment lens movement control is rather crude, but, hopefully, in time we may gain access to finer control.

Thus the 'feature idea' is to allow lens movement during an exposure.

Cheers

Garry

dmilligan

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Re: Parallel action
« Reply #3 on: February 22, 2017, 01:40:38 AM »
So you want to move the zoom (focal length) of a zoom lens? Unless I'm mistaken, the zoom ring of Canon DSLR lenses are not motorized. Do you have some external controller in mind?

garry23

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Re: Parallel action
« Reply #4 on: February 22, 2017, 08:03:50 AM »
@dmilligan

Sorry I wasn't clear enough. I know we can't control the actual zoom in FL, hence my thought was to change focus during an exposure.

The idea is to focus at just beyond the HFD so that moving the focus by, say, step size 2 or 3 will change the image because of 'lens breathing'. This will give an ICE effect.

Thus 'all' I'm trying to do is to start an exposure and change focus, i.e. coincidently.

But my gut felling is ML, or Lua, can't do this.

Cheers

Garry

a1ex

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Re: Parallel action
« Reply #5 on: February 22, 2017, 08:31:55 AM »
You can simulate the process with a focus stack sequence (or a video with rack focus, if you don't mind the lower resolution). Simply add (or average) all the frames.

garry23

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Re: Parallel action
« Reply #6 on: February 22, 2017, 02:25:24 PM »
@a1ex

Yes I too had considered that, but ideally, for the ICE effect, you really need to continuously move whilst taking an exposure.

The idea is not on the top of my list, but I thought it worth flagging up - just in case.

Cheers

Garry

a1ex

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Re: Parallel action
« Reply #7 on: February 22, 2017, 03:22:05 PM »
5D3: 0x08, 0x09, 0x01, num_steps_hi, num_steps_lo, 0x07, 0x00, 0x00: lens focus control in LiveView (also works in paused LiveView). Commands appear to be queued properly, but breaks focus distance reporting.

So, it's possible, but not exactly straightforward to implement.

Adding the frames from a video recorded with 360 degree shutter speed (pushed using Movie -> Shutter fine-tuning), during a rack focus motion, should give the same results as a single exposure with continuous focus motion (just lower resolution). The tiny delay between frames should not be noticeable.