Re: Shift lens for 3d cinematography & MAOFD

[P3D henry chung <magicmtp@xxxxxxxxxxxxxx>]

Dear John,

I began commercial photography before cinematography so I understand about
keystoning very much working before with view cameras everyday.

About the reasons for not using shift lenses for 3d cinematography:

First , we talk about dual band, two film strips filming, like they used in Terminator 3d,
in dual camera rigs, we need two cameras with same lenses shooting in perfect
sync to achieve 3d results.

I think there are only very limited amount of shift/tilt lenses in Hollywood for filming,
even if there are suitable pairs of them, they are not specially designed for 3d, most
of them are for products shooting and they took longer time to set up.

I said they are not designed for 3d because they could shift up and down as well,
which we only wanted in limited amount, they also tilts too in both directions, they
are mostly mounted on bellows instead of metal mounts.

Also they mostly came out after the filming of Terminator 3d, so it is obvious that they
cannot risk to use something not thoroughly tested before the shoot on a film of
their calibre.

Actually there is another limitation that I had just thought of, the space between the
45 degree beamsplitter and the camera is extremely small, most of the bellowed
shift tilt lenses cannot be fitted because of their sizes.

Another reason is that now convergence of the cameras can be adjusted manually
during a take, there is not yet a shift lens that had a motor in it that allows it to alter the
shift internally existed that I know of.

But, for single strip 3-d cinematography, a lot of lenses used shifting elements for
the convergence part, but they are also very rare and now limited in numbers.
Their limitation is they cannot vary the interaxials like the dual strips.

I cannot access to the MAOFD, except for the text part, do I need to have Excel ?
I only have Word.  Is there a simple chart or I must use it as a program because of the variable
distances? You see, I am not a computor expert at all.

Thanks John, I had invested nothing in the Stocks Market luckily.

Henry Chung
http://www.pac.com.hk/world/henry/




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