Re: Single lens 3D questions

[P3D Peter Davis <pdavis@xxxxxxxxxxxxxxxxxx>]

Paul Kline wrote (in response to my message:

> Peter Davis wrote:

> >   2)	Since the system depends on shallow depth of field, the
> >	effect works best with a wide aperture, so much of the
> >	picture is out of focus.  Our eyes also have a limited
> 
> The concept does NOT depend on shallow depth of field, it is the Q-dos
> implementation that causes this.  Masking the two filters with smaller
> apertures will increase depth of field.  Average separation of the
> two apertures determines the amount of 3D-depth recorded, while size
> of the apertures determines the amount of 3D-depth recorded in focus.
> 
> >I can't think of a reason for the black stripes.  My understanding is
> >that the filters would be more effective if they actually abutted in
> >the center, with no separation.
> 
> That will decrease the average separation (sacrifice 3D-depth) and
> open the apertures (sacrifice depth-of-field).  But also balance unwanted
> colorization at the sides of the image.  BTW, do you notice red and
> blue shading at the sides of your pics?  I keep hoping this can be
> avoided with some aperture mask I haven't come up with.

Well, I'm beyond the limits of my understanding here, but seems to be
that by putting the clear and black stripes in the center of their
filter, Vivitar has both reduced the area of the filters (increasing
depth of field?) and increased the separation of the two apertures
(increasing the 3D-depth?).  I'm guessing you're using "aperture" here
to refer to the area of each filter, as opposed to the opening of the
diaphragm in the lens.  So, what's wrong with the Q-dos
implementation?  Or have a totally misunderstood your explanation?

I haven't noticed any red/blue shading at the edges.  I do see
red/blue "halos" around objects in the picture, which is what I
thought was providing the depth information.

By the way, another artifact I've noticed is "cardboarding," the
illusion that the picture is composed of different planes of objects
at different distances, rather than continuously varying depth.  Is
this also a Q-dos-specific problem?  What would cause that?

Thanks.

-pd


--------
Peter Davis		       "Education is not the		 617/873-4145
BBN Educational Technologies	filling of a pail, but	    FAX: 617/873-2455
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